ORCID Profile
0000-0003-3096-3193
Current Organisation
Western Sydney University - Hawkesbury Campus
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Epigenetics (incl. Genome Methylation and Epigenomics) | Plant Cell and Molecular Biology | Genetics Not Elsewhere Classified | Genetics | Ecology And Evolution Not Elsewhere Classified | Crop And Pasture Production Not Elsewhere Classified | Plant Biology | Bioinformatics
ANZSRC Socio-Economic Objective (SEO)
Living resources (flora and fauna) | Environmentally Sustainable Plant Production not elsewhere classified | Primary products from plants | Plant Production and Plant Primary Products not elsewhere classified | Expanding Knowledge in the Biological Sciences | Biological sciences |
Related Links
Publications
Cloning and characterisation of ripening-induced ethylene biosynthetic genes from non-climacteric pineapple (Ananas comosus) fruits
Publisher: CSIRO Publishing
Date: 1998
DOI: 10.1071/PP98013
Abstract: To gain a better understanding of non-climacteric fruit ripening, pineapple was used as a model system to clone and characterise two ripening-inducible cDNAs coding for two enzymes of the ethylene biosynthetic pathway, 1-aminocyclopropane-1-carboxylate (ACC) synthase (acacc-1) and 1-aminocyclo-propane- 1-carboxylate oxidase (acaco-1) respectively. Due to the extreme acidity and high polyphenolic content of pineapple fruits, a method was optimised for the extraction of high quality RNA from fruit tissue. acacc-1 is a 1080 bp ACC synthase cDNA fragment encoding 360 amino acids including 10 of the 12 amino acid residues conserved in all aminotransferases. Comparison of the deduced amino acid sequence with previously reported ACC synthases shows between 52 and 67% similarity at the protein level. Southern analysis suggests the presence of only one copy of acacc-1 in the pineapple genome. Although some acacc-1 expression is detected in green fruits, there is a 16-fold increase in the level of acacc-1 in ripe fruit tissue. acaco-1 is a partial length cDNA clone of 611 bp which codes for 203 amino acids representing approximately 66% of the ACC oxidase open reading frame. Southern analysis suggests the presence of one or two copies of the gene in the pineapple genome. Northern analysis shows the expression of acaco-1 to be highly induced in wounded leaf tissue and to a lesser extent in ripening fruit tissue. The accumulation of ACC-synthase and ACC oxidase mRNAs during pineapple fruit ripening raises new questions about the putative role of ethylene during non-climacteric fruit ripening.
A Spontaneous Dominant-Negative Mutation within a 35S::AtMYB90 Transgene Inhibits Flower Pigment Production in Tobacco
Publisher: Public Library of Science (PLoS)
Date: 29-03-2010
Carotenoids in nature: insights from plants and beyond
Publisher: CSIRO Publishing
Date: 2011
DOI: 10.1071/FP11192
Abstract: Carotenoids are natural isoprenoid pigments that provide leaves, fruits, vegetables and flowers with distinctive yellow, orange and some reddish colours as well as several aromas in plants. Their bright colours serve as attractants for pollination and seed dispersal. Carotenoids comprise a large family of C40 polyenes and are synthesised by all photosynthetic organisms, aphids, some bacteria and fungi alike. In animals carotenoid derivatives promote health, improve sexual behaviour and are essential for reproduction. As such, carotenoids are commercially important in agriculture, food, health and the cosmetic industries. In plants, carotenoids are essential components required for photosynthesis, photoprotection and the production of carotenoid-derived phytohormones, including ABA and strigolactone. The carotenoid biosynthetic pathway has been extensively studied in a range of organisms providing an almost complete pathway for carotenogenesis. A new wave in carotenoid biology has revealed implications for epigenetic and metabolic feedback control of carotenogenesis. Developmental and environmental signals can regulate carotenoid gene expression thereby affecting carotenoid accumulation. This review highlights mechanisms controlling (1) the first committed step in phytoene biosynthesis, (2) flux through the branch to synthesis of α- and β-carotenes and (3) metabolic feedback signalling within and between the carotenoid, MEP and ABA pathways.
The promoter of the Arabidopsis PIN6 auxin transporter enabled strong expression in the vasculature of roots, leaves, floral stems and reproductive organs
Publisher: Informa UK Limited
Date: 2014
DOI: 10.4161/PSB.27898
Author response: A cis-carotene derived apocarotenoid regulates etioplast and chloroplast development
Publisher: eLife Sciences Publications, Ltd
Date: 04-12-2019
The mitochondrial outer membrane AAA ATP ase AtOM 66 affects cell death and pathogen resistance in A rabidopsis thaliana
Publisher: Wiley
Date: 27-10-2014
DOI: 10.1111/TPJ.12665
Abstract: One of the most stress-responsive genes encoding a mitochondrial protein in Arabidopsis (At3g50930) has been annotated as AtBCS1 (cytochrome bc1 synthase 1), but was previously functionally uncharacterised. Here, we show that the protein encoded by At3g50930 is present as a homo-multimeric protein complex on the outer mitochondrial membrane and lacks the BCS1 domain present in yeast and mammalian BCS1 proteins, with the sequence similarity restricted to the AAA ATPase domain. Thus we propose to re-annotate this protein as AtOM66 (Outer Mitochondrial membrane protein of 66 kDa). While transgenic plants with reduced AtOM66 expression appear to be phenotypically normal, AtOM66 over-expression lines have a distinct phenotype, showing strong leaf curling and reduced starch content. Analysis of mitochondrial protein content demonstrated no detectable changes in mitochondrial respiratory complex protein abundance. Consistent with the stress inducible expression pattern, over-expression lines of AtOM66 are more tolerant to drought stress but undergo stress-induced senescence earlier than wild type. Genome-wide expression analysis revealed a constitutive induction of salicylic acid-related (SA) pathogen defence and cell death genes in over-expression lines. Conversely, expression of SA marker gene PR-1 was reduced in atom66 plants, while jasmonic acid response genes PDF1.2 and VSP2 have increased transcript abundance. In agreement with the expression profile, AtOM66 over-expression plants show increased SA content, accelerated cell death rates and are more tolerant to the biotrophic pathogen Pseudomonas syringae, but more susceptible to the necrotrophic fungus Botrytis cinerea. In conclusion, our results demonstrate a role for AtOM66 in cell death and lifying SA signalling.
Simulated Herbivory: The Key to Disentangling Plant Defence Responses
Publisher: Elsevier BV
Date: 05-2019
DOI: 10.1016/J.TREE.2019.01.008
Abstract: Plants are subjected to a multitude of stimuli during insect herbivory, resulting in a complex and cumulative defence response. Breaking down the components of herbivory into specific stimuli and identifying the mechanisms of defence associated with them has thus far been challenging. Advances in our understanding of responses to inconspicuous stimuli, such as those induced by microbial symbionts in herbivore secretions and mechanical stimulation caused by insects, have illuminated the intricacies of herbivory. Here, we provide a synthesis of the interacting impacts of herbivory on plants and the consequential complexities associated with uncoupling defence responses. We propose that simulated herbivory should be used to complement true herbivory to decipher the mechanisms of insect herbivore-induced plant defence responses.
Promoting gene expression in plants by permissive histone lysine methylation
Publisher: Informa UK Limited
Date: 06-2009
DOI: 10.4161/PSB.4.6.8316
Smart glass impacts stomatal sensitivity of greenhouse Capsicum through altered light
Publisher: Oxford University Press (OUP)
Date: 23-01-2021
DOI: 10.1093/JXB/ERAB028
Abstract: Optical films that alter light transmittance may reduce energy consumption in high-tech greenhouses, but their impact on crop physiology remains unclear. We compared the stomatal responses of Capsicum plants grown hydroponically under control glass (70% diffuse light) or the smart glass (SG) film ULR-80, which blocked & % of short-wave radiation and ~9% of photosynthetically active radiation (PAR). SG had no significant effects on steady-state (gs) or maximal (gmax) stomatal conductance. In contrast, SG reduced stomatal pore size and sensitivity to exogenous abscisic acid (ABA), thereby increasing rates of leaf water loss, guard cell K+ and Cl– efflux, and Ca2+ influx. SG induced faster stomatal closing and opening rates on transition between low (100 µmol m–2 s–1) and high PAR (1500 µmol m–2 s–1), which compromised water use efficiency relative to control plants. The fraction of blue light (0% or 10%) did not affect gs in either treatment. Increased expression of stomatal closure and photoreceptor genes in epidermal peels of SG plants is consistent with fast stomatal responses to light changes. In conclusion, stomatal responses of Capsicum to SG were more affected by changes in light intensity than spectral quality, and re-engineering of the SG should maximize PAR transmission, and hence CO2 assimilation.
Mechanical stress acclimation in plants: Linking hormones and somatic memory to thigmomorphogenesis
Publisher: Wiley
Date: 18-01-2022
DOI: 10.1111/PCE.14252
Abstract: A single event of mechanical stimulation is perceived by mechanoreceptors that transduce rapid transient signalling to regulate gene expression. Prolonged mechanical stress for days to weeks culminates in cellular changes that strengthen the plant architecture leading to thigmomorphogenesis. The convergence of multiple signalling pathways regulates mechanically induced tolerance to numerous biotic and abiotic stresses. Emerging evidence showed prolonged mechanical stimulation can modify the baseline level of gene expression in naive tissues, heighten gene expression, and prime disease resistance upon a subsequent pathogen encounter. The phenotypes of thigmomorphogenesis can persist throughout growth without continued stimulation, revealing somatic‐stress memory. Epigenetic processes regulate TOUCH gene expression and could program transcriptional memory in differentiating cells to program thigmomorphogenesis. We discuss the early perception, gene regulatory and phytohormone pathways that facilitate thigmomorphogenesis and mechanical stress acclimation in Arabidopsis and other plant species. We provide insights regarding: (1) the regulatory mechanisms induced by single or prolonged events of mechanical stress, (2) how mechanical stress confers transcriptional memory to induce cross‐acclimation to future stress, and (3) why thigmomorphogenesis might resemble an epigenetic phenomenon. Deeper knowledge of how prolonged mechanical stimulation programs somatic memory and primes defence acclimation could transform solutions to improve agricultural sustainability in stressful environments.
GOLDEN TANGERINE TOMATO ROOTS SHOW INCREASED ACCUMULATION OF ACYCLIC CAROTENOIDS, LESS ABSCISIC ACID, DROUGHT SENSITIVITY, AND IMPAIRED ENDOMYCORRHIZAL COLONIZATION
Publisher: Cold Spring Harbor Laboratory
Date: 09-12-2021
DOI: 10.1101/2021.12.07.471680
Abstract: Heirloom golden tomato fruit varieties are highly nutritious as they accumulate tetra- cis -lycopene, which has a higher bioavailability and recognised health benefits in treating anti-inflammatory diseases compared to all- trans -lycopene isomers found in red tomatoes. We investigated if photoisomerization of tetra- cis -lycopene occurs in roots of the golden tangerine Micro-Tom variety ( tang mic ), and how this affects root to shoot biomass, mycorrhizal colonization, abscisic acid accumulation, and responses to drought. tang mic plants grown in soil under glasshouse conditions displayed a reduction in height, number of flowers, fruit yield, and root length compared to wild type (WT). Soil inoculation with Rhizophagus irregularis revealed fewer arbuscules and other fungal structures in the endodermal cells of roots in tang mic relative to WT. The roots of tang mic hyperaccumulated acyclic cis -carotenes, while only trace levels of xanthophylls and abscisic acid were detected. In response to a water deficit, leaves from the tang mic plants displayed a rapid decline in maximum quantum yield of photosystem II compared to WT, indicating a defective root to shoot signalling response to drought. The lack of xanthophylls biosynthesis in tang mic roots reduced abscisic acid levels, thereby likely impairing endomycorrhiza colonisation and drought-induced root to shoot signalling. Photoisomerization of prolycopene to lycopene is limited in root plastids. Roots of tangerine reveal an important tissue sink to store micronutrients such as prolycopene. Roots of tangerine lack ABA and show impaired mycorrhizal colonization. The tangerine plant is drought sensitive and has a smaller biomass as well as reduced yield.
Molecular Evolution and Interaction of Membrane Transport and Photoreception in Plants
Publisher: Frontiers Media SA
Date: 11-10-2019
A cis-carotene derived apocarotenoid regulates etioplast and chloroplast development
Publisher: eLife Sciences Publications, Ltd
Date: 31-01-2020
DOI: 10.7554/ELIFE.45310
Abstract: Carotenoids are a core plastid component and yet their regulatory function during plastid biogenesis remains enigmatic. A unique carotenoid biosynthesis mutant, carotenoid chloroplast regulation 2 ( ccr2 ), that has no prolamellar body (PLB) and normal PROTOCHLOROPHYLLIDE OXIDOREDUCTASE (POR) levels, was used to demonstrate a regulatory function for carotenoids and their derivatives under varied dark-light regimes. A forward genetics approach revealed how an epistatic interaction between a ζ-carotene isomerase mutant ( ziso-155 ) and ccr2 blocked the biosynthesis of specific cis -carotenes and restored PLB formation in etioplasts. We attributed this to a novel apocarotenoid retrograde signal, as chemical inhibition of carotenoid cleavage dioxygenase activity restored PLB formation in ccr2 etioplasts during skotomorphogenesis. The apocarotenoid acted in parallel to the repressor of photomorphogenesis, DEETIOLATED1 (DET1), to transcriptionally regulate PROTOCHLOROPHYLLIDE OXIDOREDUCTASE (POR), PHYTOCHROME INTERACTING FACTOR3 (PIF3) and ELONGATED HYPOCOTYL5 (HY5). The unknown apocarotenoid signal restored POR protein levels and PLB formation in det1 , thereby controlling plastid development.
Contrasting impacts of herbivore induction and elevated atmospheric CO2 on silicon defences and consequences for subsequent herbivores
Publisher: Wiley
Date: 05-04-2022
DOI: 10.1111/EEA.13168
Abstract: Plants are often sequentially attacked by multiple herbivores feeding by one herbivore can alter host plant quality that affects the performance of subsequent herbivores. Previous studies suggest that silicon (Si) is a highly inducible defence in grasses (Poaceae) following herbivory, so could mediate such temporally separated insect herbivore interactions. Elevated atmospheric CO 2 concentrations (eCO 2 ), in contrast, often reduce Si accumulation, which potentially weakens this interaction. We examined the effects of prior feeding by Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) on the performance of crickets, Acheta domesticus (L.) (Orthoptera: Gryllidae), subsequently feeding on the same plant. We used Brachypodium distachyon (L.) P. Beauv. grass supplemented or non‐supplemented with Si and grown in the glasshouse maintained at ambient (aCO 2 ) or eCO 2 concentrations. As hypothesized, prior feeding by caterpillars induced Si accumulation. Despite eCO 2 reducing Si accumulation, initial herbivore induction of Si negated the effects of eCO 2 . Both, previous caterpillar herbivory and Si supplementation reduced cricket performance. Si induction by successive herbivory was additive. Plant biomass was similar in plants attacked by caterpillars alone or both herbivores, suggesting that initial Si induction by caterpillars deterred feeding by crickets. Our results demonstrate that Si induction by one herbivore negatively impacts successive herbivores, as has been demonstrated for secondary metabolite‐mediated interactions. Uniquely, however, Si induction is an irreversible defence and potentially a stronger, or perhaps longer‐lasting mediator of such herbivore interactions in some plant taxa.
Metabolic similarity of plant and human: implications for efficacy and regulatory compliance of herbal therapies
Publisher: Eman Research, Ltd.
Date: 18-05-2019
DOI: 10.25163/AHI.2046
Purification and use of carotenoid standards to quantify cis-trans geometrical carotenoid isomers in plant tissues
Publisher: Elsevier
Date: 2022
DOI: 10.1016/BS.MIE.2022.01.005
Abstract: Reverse-phase high-performance liquid chromatography (HPLC) is a preferred method used to identify and quantify carotenoids. Here, we describe a straightforward, reliable, and cost-effective protocol to purify and develop in idual carotenoid standards for absolute quantification of carotenoids, including selected cis-trans (geometric) isomers. Analytical techniques to extract, purify and collect in idual carotenoids using an HPLC system equipped with a Diode Array Detector (DAD) and fraction collector are described. Carotenoids were separated and identified by their characteristic ultraviolet-visible (UV-Vis) absorption spectra and in idually isolated based on their retention times using a C30 column. This chapter outlines how to prepare standard calibration curves using known quantities of purified and/or commercially available carotenoids. A series of molar extinction and slope coefficients for phytoene, phytofluene, ζ-carotene, neurosporene, pro-lycopene, all trans-lycopene, lutein, β-carotene, zeaxanthin, antheraxanthin, violaxanthin, neoxanthin, capsanthin, capsorubin and β-cryptoxanthin are defined to enable absolute quantification of their abundance in plant, animal, and bacterial tissues. Different approaches for reporting carotenoid abundance by absolute concentration, relative composition, and/or using ratios of different pigments are provided as a convenient resource for carotenoid researchers.
In vivo characterization of plant promoter element interaction using synthetic promoters
Publisher: Springer Science and Business Media LLC
Date: 25-07-2007
DOI: 10.1007/S11248-007-9117-8
Abstract: Short directly-repeated (DR) DNA enhancer elements of plant viral origin were analyzed for their ability, both in idually and in combination, to influence in vivo transcription when inserted upstream from a minimal CaMV35S promoter. Synthetic promoters containing multiple copies and/or combinations of DR cassettes were tested for their effect upon reporter gene (luciferase) expression using an Agrobacteria-based leaf-infiltration transient assay and within stably transformed plants (Nicotiana tabacum). Transgenic plants harboring constructs containing different numbers or combinations of DR cassettes were further tested to look for tissue-specific expression patterns and potential promoter response to the infiltration process employed during transient expression. Multimerization of DR elements produced enhancer activity that was in general additive, increasing reporter activity in direct proportion to the number of DR cassettes within the test promoter. In contrast, combinations of different DR cassettes often functioned synergistically, producing reporter enhancement markedly greater then the sum of the combined DR activities. Several of the DR constructs responded to Agrobacteria (lacking T-DNA) infiltration of transgenic leaves by an induction (2 elements) or reduction (1 element) in reporter activity. Combinations of DR cassettes producing the strongest enhancement of reporter activity were used to create two synthetic promoters (SynPro3 and SynPro5) that drive leaf reporter activities at levels comparable to the CaMV35S promoter. Characterization of these synthetic promoters in transformed tobacco showed strong reporter expression at all stages of development and in most tissues. The arrangement of DR elements within SynPro3 and SynPro5 appears to play a role in defining tissue-specificity of expression and/or Agrobacteria-infusion responsiveness.
Reducing PSY activity fine tunes threshold levels of acis-carotene-derived signal that regulates the PIF3/HY5 module and plastid biogenesis
Publisher: Cold Spring Harbor Laboratory
Date: 30-06-2023
DOI: 10.1101/2023.06.29.546996
Abstract: PHYTOENE SYNTHASE (PSY) is a rate-limiting enzyme catalysing the first committed step of carotenoid biosynthesis, and changes in PSY gene expression and/or protein activity alter carotenoid composition and plastid differentiation in plants. Here we identified four genetic variants of PSY ( psy −4 , psy −90 , psy −130 and psy −145 ) using a forward genetics approach that rescued leaf virescence phenotypes displayed by the Arabidopsis CAROTENOID ISOMERASE (CRTISO) mutant ccr2 ( carotenoid and chloroplast regulation 2 ) when grown under a shorter photoperiod. The four non-lethal mutations affected alternative splicing, enzyme-substrate interactions, and PSY:ORANGE multi-enzyme complex binding, constituting the dynamic posttranscriptional fine-tuning of PSY levels and activity without changing localization to the stroma and protothylakoid membranes. psy genetic variants did not alter overall total xanthophyll or cis-carotene accumulation in ccr2 yet reduced specific acyclic linear cis -carotenes linked to the biosynthesis of a yet-to-be-identified apocarotenoid signal. ccr2 psy variants modulated the ratio of PHYTOCHROME-INTERACTING FACTOR 3/ELONGATED HYPOCOTYL 5 (PIF3/HY5), displayed a normal PLB formation in etioplasts, and chlorophyll accumulation during seedling photomorphogenesis. Thus, suppressing PSY activity and impairing PSY:ORANGE protein interactions reveals how threshold specific cis -carotene levels can be fine-tuned through holoenzyme-metabolon interactions to control plastid development. Manipulation of the PHYTOENE SYNTHASE catalytic activity in concert with its regulatory protein, ORANGE, reduces threshold levels of acyclic linear cis -carotenes that signal control over plastid biogenesis in dark and light grown Arabidopsis seedlings
An extreme heatwave enhanced the xanthophyll de-epoxidation state in leaves of Eucalyptus trees grown in the field
Publisher: Springer Science and Business Media LLC
Date: 10-01-2020
Alternative splicing, activation of cryptic exons and amino acid substitutions in carotenoid biosynthetic genes are associated with lutein accumulation in wheat endosperm
Publisher: Springer Science and Business Media LLC
Date: 28-03-2009
DOI: 10.1007/S10142-009-0121-3
Abstract: Endosperm carotenoid content in wheat is a primary determinant of flour colour and this affects both the nutritional value of the grain and its utility for different applications. Utilising wheat rice synteny two genes, epsilon-cyclase (epsilon-LCY) and phytoene synthase (Psy-A1), were identified as candidate genes for two of the QTL affecting lutein content in wheat endosperm. Analysis of the sequence changes in epsilon-LCY and Psy-A1 revealed possible causal mechanisms for both QTL. A point mutation in epsilon-LCY results in the substitution of a conserved amino acid in the high lutein allele. This substitution has been observed in high lutein-accumulating species from the Gentiales order. In Psy-A1, a sequence duplication at the end of exon 2 creates a new splice site and causes alternative splicing of the transcript and activation of a cryptic exon, resulting in four different transcripts: a wild-type transcript, two transcripts with early terminations and a transcript that would produce an in-frame, albeit longer protein. Only the wild-type splice variant produced an enzymatically active protein and its mRNA abundance was reduced by titration with the other splice variants. This reduction in wild-type mRNA is argued to result in a reduction in PSY protein and thus carotenoid content in wheat.
Transcriptional control of SET DOMAIN GROUP 8 and CAROTENOID ISOMERASE during Arabidopsis development.
Publisher: Elsevier BV
Date: 2010
DOI: 10.1093/MP/SSP092
Abstract: Carotenoids are pigments required for photosynthesis, photoprotection and the production of carotenoid-derived hormones such as ABA and strigolactones. The carotenoid biosynthetic pathway bifurcates after lycopene to produce epsilon- and beta-carotenoids and this branch is critical for determining carotenoid composition. Here, we show how the branch point can be regulated by the chromatin-modifying histone methyltransferase, Set Domain Group 8 (SDG8) targeting the carotenoid isomerase (CRTISO). SDG8 is required to maintain permissive expression of CRTISO during seedling development, in leaves, shoot apex, and some floral organs. The CRTISO and SDG8 promoters show overlapping tissue-specific patterns of reporter gene activity. Interestingly, CRTISO showed atypical reporter gene expression in terms of greater variability between different lines compared to the Cauliflower Mosaic Virus 35S promoter (CaMV35s) and epsilonLCY promoters, potentially due to chromosomal position effects. Regulation of the CRTISO promoter was dependent in part upon the presence or absence of SDG8. Knockouts of SDG8 (carotenoid and chloroplast regulation (ccr1)) and CRTISO (ccr2) result in altered carotenoid composition and this could be restored in ccr2 using the CaMV35s or CRTISO promoters. In contrast, varying degrees of GUS expression and carotenoid complementation by CRTISO overexpression using CaMV35S or CRTISO promoters in the ccr1 background demonstrated that both the CRTISO promoter and open reading frame are necessary for SDG8-mediated expression of CRTISO.
An in vivo, luciferase-based, Agrobacterium-infiltration assay system: implications for post-transcriptional gene silencing
Publisher: Springer Science and Business Media LLC
Date: 08-03-2006
DOI: 10.1007/S00425-006-0250-Z
Abstract: An in vivo assay system for analyzing transient luciferase expression in tobacco leaves infused with Agrobacterium tumefaciens is described. The system makes use of A. tumefaciens harboring T-DNA vectors containing either an intron-containing firefly (Photinus pyralis) luciferase (EC 1.13.12.7) gene or an intron-containing sea pansy (Renilla reniformis) luciferase (EC 1.13.12.5) gene. Single or mixed Agrobacterium lines were infiltrated into leaf tissues (Nicotiana tabacum or Nicotiana benthamiana) through stomatal openings and leaf disks from infused areas floated on reaction buffers specific to each enzyme. Photons emitted were then measured to determine reporter gene activity. Parameters affecting assay reliability and sensitivity were tested, including: buffer composition bacterial density infusion location reaction kinetics and environmental factors (light and temperature). The resulting in vivo assay system generates results comparable to those obtained using a commercially available in vitro dual-luciferase(R) reporter gene assay, and reports relative expression levels, as well as induction characteristics, analogous to those obtained using leaf tissue from stably transformed plants harboring the same promoter::gene constructs. Light and temperature were observed to markedly impact transient reporter activities. Co-expression of viral suppressors of post-transcriptional gene silencing (PTGS), HcPro, p19 and AC2, confirms the occurrence of PTGS within infused zones, and provides a convenient mechanism for PTGS analysis. The in vivo transient assay was used to examine the effect on PTGS of factors such as: promoter strength incubation temperature and double-stranded RNA production. Results from these assays provide insight into the mechanism(s) used by plants to trigger and maintain PTGS.
Leaf-age dependent response of carotenoid accumulation to elevated CO2 in Arabidopsis.
Publisher: Elsevier BV
Date: 06-2018
DOI: 10.1016/J.ABB.2018.03.034
Abstract: Carotenoids contribute to photosynthesis, photoprotection, phytohormone and apocarotenoid biosynthesis in plants. Carotenoid-derived metabolites control plant growth, development and signalling processes and their accumulation can depend upon changes in the environment. Elevated carbon dioxide (eCO
Sonic-induced cellular vibrations disrupt poricidal cone trichomes to boost tomato floral pollination
Publisher: Research Square Platform LLC
Date: 03-08-2023
DOI: 10.21203/RS.3.RS-3198339/V1
Abstract: Artificial pollination methods rely primarily on air-jets, vibrating wands and trellis tapping which can spread pathogens. This problem can be addressed by non-contact sonic techniques that vibrate cells via sound waves yet how frequency and intensity affect pollination, seed set and fruit size remain unclear. Our study systematic characterizes frequency-dependent vibration events on greenhouse-grown tomato flowers comparing them with contact-induced oscillations from a vibrating wand and a mechanical shaker arm. Sonic vibrations in the frequency range from 50 to 10,000 Hz increased pollination, fruit size, weight, and seed set in Sweetelle and Endeavour commercial varieties. Scanning electron microscopy revealed sonication loosened the trichomes joining the poricidal cone lobes that encase the anthers filled with pollen. Ultra-sonic frequencies enlarged fruit size, whereas seed set remained constant thereby challenging the floral cells power-law rheological characteristics in different frequency scales. Our bioacoustics non-contact precision technology can be used to boost tomato floral self-pollination. Teaser Leveraging bioacoustics from bees and bats to boost precision pollination of tomato flowers and fruit size in commercial varieties
cis/trans Carotenoid Extraction, Purification, Detection, Quantification, and Profiling in Plant Tissues
Publisher: Springer US
Date: 20-11-2020
DOI: 10.1007/978-1-4939-9952-1_11
Abstract: Reverse phase high-performance liquid chromatography (HPLC) is the method of choice used in biological, health, and food research to identify, quantify, and profile carotenoid species. The identification and quantification of cis- and/or trans-carotene and xanthophyll isomers in plant tissues can be affected by the method of s le preparation and extraction, as well as the HPLC column chemistry and the solvent gradient. There is a high degree of heterogeneity in existing methods in terms of their ease, efficiency, and accuracy. We describe a simple carotenoid extraction method and two different optimised HPLC methods utilizing C18 or C30 reverse-phase columns. We outline applications, advantages, and disadvantages for using these reverse phase columns to detect xanthophylls and cis-carotenes in wild-type photosynthetic leaves and mutant dark-grown etiolated seedlings, respectively. Resources are provided to profile in idual species based upon their spectral properties and retention time, as well as quantify carotenoids by their composition and absolute levels in different plant tissues.
Transgene Silencing and Transgene-Derived siRNA Production in Tobacco Plants Homozygous for an Introduced AtMYB90 Construct
Publisher: Public Library of Science (PLoS)
Date: 17-02-2012
Source to sink: regulation of carotenoid biosynthesis in plants
Publisher: Elsevier BV
Date: 05-2010
DOI: 10.1016/J.TPLANTS.2010.02.003
Abstract: Carotenoids are a erse group of colourful pigments naturally found in plants, algae, fungi and bacteria. They play essential roles in development, photosynthesis, root-mycorrhizal interactions and the production of phytohormones, such as abscisic acid and strigolactone. Carotenoid biosynthesis is regulated throughout the life cycle of a plant with dynamic changes in composition matched to prevailing developmental requirements and in response to external environmental stimuli. There are key regulatory nodes in the pathway that control the flux of metabolites into the pathway and alter flux through the pathway. The molecular nature of the mechanisms regulating carotenoid biosynthesis, including evidence for metabolite feedback, transcription and epigenetic control as well as their accumulation, storage and degradation will be the focus of this review.
cis-carotene biosynthesis, evolution and regulation in plants: The emergence of novel signaling metabolites
Publisher: Elsevier BV
Date: 09-2018
DOI: 10.1016/J.ABB.2018.07.014
Abstract: Carotenoids are isoprenoid pigments synthesised by plants, algae, photosynthetic bacteria as well as some non-photosynthetic bacteria, fungi and insects. Abundant carotenoids found in nature are synthesised via a linear route from phytoene to lycopene after which the pathway bifurcates into cyclised α- and β-carotenes. Plants evolved additional steps to generate a ersity of cis-carotene intermediates, which can accumulate in fruits or tissues exposed to an extended period of darkness. Enzymatic or oxidative cleavage, light-mediated photoisomerization and histone modifications can affect cis-carotene accumulation. cis-carotene accumulation has been linked to the production of signaling metabolites that feedback and forward to regulate nuclear gene expression. When cis-carotenes accumulate, plastid biogenesis and operational control can become impaired. Carotenoid derived metabolites and phytohormones such as abscisic acid and strigolactones can fine-tune cellular homeostasis. There is a hunt to identify a novel cis-carotene derived apocarotenoid signal and to elucidate the molecular mechanism by which it facilitates communication between the plastid and nucleus. In this review, we describe the biosynthesis and evolution of cis-carotenes and their links to regulatory switches, as well as highlight how cis-carotene derived apocarotenoid signals might control organelle communication, physiological and developmental processes in response to environmental change.
Current Technologies and Target Crops: A Review on Australian Protected Cropping
Publisher: MDPI AG
Date: 08-06-2022
DOI: 10.3390/CROPS2020013
Abstract: Protected cropping offers a way to bolster food production in the face of climate change and deliver healthy food sustainably with fewer resources. However, to make this way of farming economically viable, we need to consider the status of protected cropping in the context of available technologies and corresponding target horticultural crops. This review outlines existing opportunities and challenges that must be addressed by ongoing research and innovation in this exciting but complex field in Australia. Indoor farm facilities are broadly categorised into the following three levels of technological advancement: low-, medium- and high-tech with corresponding challenges that require innovative solutions. Furthermore, limitations on indoor plant growth and protected cropping systems (e.g., high energy costs) have restricted the use of indoor agriculture to relatively few, high value crops. Hence, we need to develop new crop cultivars suitable for indoor agriculture that may differ from those required for open field production. In addition, protected cropping requires high start-up costs, expensive skilled labour, high energy consumption, and significant pest and disease management and quality control. Overall, protected cropping offers promising solutions for food security, while reducing the carbon footprint of food production. However, for indoor cropping production to have a substantial positive impact on global food security and nutritional security, the economical production of erse crops will be essential.
Light-altering cover materials and sustainable greenhouse production of vegetables: a review
Publisher: Springer Science and Business Media LLC
Date: 11-06-2021
Epigenetic Control of Carotenogenesis During Plant Development
Publisher: Informa UK Limited
Date: 02-01-2021
Regulation of Carotenoid Composition and Shoot Branching inArabidopsisby a Chromatin Modifying Histone Methyltransferase, SDG8
Publisher: Oxford University Press (OUP)
Date: 2009
Abstract: Carotenoid pigments are critical for plant survival, and carotenoid composition is tuned to the developmental stage, tissue, and to environmental stimuli. We report the cloning of the CAROTENOID CHLOROPLAST REGULATORY1 (CCR1) gene. The ccr1 mutant has increased shoot branching and altered carotenoid composition, namely, reduced lutein in leaves and accumulation of cis-carotenes in dark-grown seedlings. The CCR1 gene was previously isolated as EARLY FLOWERING IN SHORT DAYS and encodes a histone methyltransferase (SET DOMAIN GROUP 8) that methylates histone H3 on Lys 4 and/or 36 (H3K4 and H3K36). ccr1 plants show reduced trimethyl-H3K4 and increased dimethyl-H3K4 surrounding the CAROTENOID ISOMERASE (CRTISO) translation start site, which correlates with low levels of CRTISO mRNA. Microarrays of ccr1 revealed the downregulation of 85 genes, including CRTISO and genes associated with signaling and development, and upregulation of just 28 genes. The reduction in CRTISO transcript abundance explains the altered carotenoid profile. The changes in shoot branching are additive with more axillary branching mutants, but the altered carotenoid profile may partially affect shoot branching, potentially by perturbed biosynthesis of the carotenoid substrates of strigolactones. These results are consistent with SDG8 regulating shoot meristem activity and carotenoid biosynthesis by modifying the chromatin surrounding key genes, including CRTISO. Thus, the level of lutein, the most abundant carotenoid in higher plants that is critical for photosynthesis and photoprotection, appears to be regulated by a chromatin modifying enzyme in Arabidopsis thaliana.
Prolonged cold exposure to Arabidopsis juvenile seedlings extends vegetative growth and increases the number of shoot branches.
Publisher: Informa UK Limited
Date: 07-07-2020
An Uncharacterized Apocarotenoid-Derived Signal Generated in ζ-Carotene Desaturase Mutants Regulates Leaf Development and the Expression of Chloroplast and Nuclear Genes inArabidopsis
Publisher: Oxford University Press (OUP)
Date: 06-2014
Abstract: In addition to acting as photoprotective compounds, carotenoids also serve as precursors in the biosynthesis of several phytohormones and proposed regulatory signals. Here, we report a signaling process derived from carotenoids that regulates early chloroplast and leaf development. Biosynthesis of the signal depends on ζ-carotene desaturase activity encoded by the ζ-CAROTENE DESATURASE (ZDS)/CHLOROPLAST BIOGENESIS5 (CLB5) gene in Arabidopsis thaliana. Unlike other carotenoid-deficient plants, zds/clb5 mutant alleles display profound alterations in leaf morphology and cellular differentiation as well as altered expression of many plastid- and nucleus-encoded genes. The leaf developmental phenotypes and gene expression alterations of zds/clb5/spc1 de181 plants are rescued by inhibitors or mutations of phytoene desaturase, demonstrating that phytofluene and/or ζ-carotene are substrates for an unidentified signaling molecule. Our work further demonstrates that this signal is an apocarotenoid whose synthesis requires the activity of the carotenoid cleavage dioxygenase CCD4.
Smart Film Impacts Stomatal Sensitivity of Greenhouse Capsicum Through Altered Light
Publisher: Cold Spring Harbor Laboratory
Date: 24-09-2020
DOI: 10.1101/2020.09.22.309427
Abstract: Optical films that alter light transmittance may reduce energy consumption in high-tech greenhouses, but their impact on crop physiology remains unclear. We compared the stomatal responses of capsicum plants grown hydroponically under control glass (70% diffuse light) or smart glass (SG) film ULR-80, which blocked % of ultraviolet light and 19% of photosynthetically active radiation (PAR). SG had no significant effects on steady-state ( g s ) or maximal ( g max ) stomatal conductance. In contrast, SG reduced stomatal pore size and sensitivity to exogenous ABA thereby increasing rates of leaf water loss, guard cell K + and Cl - efflux, and Ca 2+ influx. The transition between low (100 μmol m −2 s −1 ) and high (1500 μmol m −2 s −1 ) PAR induced faster stomatal closing and opening rates in SG relative to control plants. The fraction of blue light (0% or 10%) did not affect g s , but induced stomatal oscillations in SG plants. Increased expression of stomatal closure and photoreceptor genes in epidermal peels of SG plants is consistent with fast stomatal responses to light changes. In conclusion, light intensity was more critical than spectral quality for optimal stomatal responses of capsicum under SG, and re-engineering of the SG should maximize PAR transmission to maintain a better stomatal development. Capsicum plants grown under SG film exhibit decreased stomatal pore area, higher water loss and reduced ABA-sensitivity. SG-grown plants have faster rates of stomatal closing and opening in response to light intensity changes. SG increases efflux of K + and Cl - and influx of Ca 2+ of guard cells. SG upregulated the expression of key genes involved in stomatal regulation and light sensing.
Advancing herbal medicine through metabolic pathway analysis in plants and animals for routine pharmacological assessments
Publisher: Elsevier BV
Date: 05-2019
A foliar pigment-based bioassay for interrogating chloroplast signalling revealed that carotenoid isomerisation regulates chlorophyll abundance
Publisher: Springer Science and Business Media LLC
Date: 17-02-2022
DOI: 10.1186/S13007-022-00847-5
Abstract: Some plastid-derived metabolites can control nuclear gene expression, chloroplast biogenesis, and chlorophyll biosynthesis. For ex le, norflurazon (NFZ) induced inhibition of carotenoid biosynthesis in leaves elicits a protoporphyrin IX (Mg-ProtoIX) retrograde signal that controls chlorophyll biosynthesis and chloroplast development. Carotenoid cleavage products, known as apocarotenoids, also regulate plastid development. The key steps in carotenoid biosynthesis or catabolism that can regulate chlorophyll biosynthesis in leaf tissues remain unclear. Here, we established a foliar pigment-based bioassay using Arabidopsis rosette leaves to investigate plastid signalling processes in young expanding leaves comprising rapidly iding and expanding cells containing active chloroplast biogenesis. We demonstrate that environmental treatments (extended darkness and cold exposure) as well as chemical (norflurazon NFZ) inhibition of carotenoid biosynthesis, reduce chlorophyll levels in young, but not older leaves of Arabidopsis . Mutants with disrupted xanthophyll accumulation, apocarotenoid phytohormone biosynthesis (abscisic acid and strigolactone), or enzymatic carotenoid cleavage, did not alter chlorophyll levels in young or old leaves. However, perturbations in acyclic cis -carotene biosynthesis revealed that disruption of CAROTENOID ISOMERASE (CRTISO), but not ZETA-CAROTENE ISOMERASE (Z-ISO) activity, reduced chlorophyll levels in young leaves of Arabidopsis plants. NFZ-induced inhibition of PHYTOENE DESATURASE (PDS) activity caused higher phytoene accumulation in younger crtiso leaves compared to WT indicating a continued substrate supply from the methylerythritol 4-phosphate (MEP) pathway. The Arabidopsis foliar pigment-based bioassay can be used to differentiate signalling events elicited by environmental change, chemical treatment, and/or genetic perturbation, and determine how they control chloroplast biogenesis and chlorophyll biosynthesis. Genetic perturbations that impaired xanthophyll biosynthesis and/or carotenoid catabolism did not affect chlorophyll biosynthesis. The lack of CAROTENOID ISOMERISATION reduced chlorophyll accumulation, but not phytoene biosynthesis in young leaves of Arabidopsis plants growing under a long photoperiod. Findings generated using the newly customised foliar pigment-based bioassay implicate that carotenoid isomerase activity and NFZ-induced inhibition of PDS activity elicit different signalling pathways to control chlorophyll homeostasis in young leaves of Arabidopsis .
Periodic root branching in Arabidopsis requires synthesis of an uncharacterized carotenoid derivative
Publisher: Proceedings of the National Academy of Sciences
Date: 17-03-2014
Abstract: A fundamental question in developmental biology is how patterns are established in space and time. In plants, key differences in root system architecture are attributed to the spatial distribution pattern of lateral roots (LRs), yet how the pattern of LRs is established is only beginning to be understood. We demonstrate that the establishment of sites competent to form LRs roots requires carotenoid biosynthesis. Furthermore, our results implicate an uncharacterized carotenoid-derived molecule that functions non–cell-autonomously, specifically in LR formation. The results of this study reveal novel aspects of carotenoid biology and expand the roles of carotenoid-derived molecules into root developmental patterning.
Acis-carotene derived apocarotenoid regulates etioplast and chloroplast development
Publisher: Cold Spring Harbor Laboratory
Date: 23-01-2019
DOI: 10.1101/528331
Abstract: Carotenoids are core plastid components, yet a regulatory function during plastid biogenesis remains enigmatic. A unique carotenoid biosynthesis mutant, carotenoid chloroplast regulation 2 ( ccr2 ), that has no prolamellar body (PLB) and normal PROTOCHLOROPHYLLIDE OXIDOREDUCTASE (POR) levels, was used to demonstrate a regulatory function for carotenoids under varied dark-light regimes. A forward genetics approach revealed how an epistatic interaction between a (-carotene isomerase mutant ( ziso-155 ) and ccr2 blocked the biosynthesis of specific cis -carotenes and restored PLB formation in etioplasts. We attributed this to a novel apocarotenoid signal, as chemical inhibition of carotenoid cleavage dioxygenase activity restored PLB formation in ccr2 etioplasts during skotomorphogenesis. The apocarotenoid acted in parallel to the transcriptional repressor of photomorphogenesis, DEETIOLATED1 (DET1), to post-transcriptionally regulate PROTOCHLOROPHYLLIDE OXIDOREDUCTASE (POR), PHYTOCHROME INTERACTING FACTOR3 (PIF3) and ELONGATED HYPOCOTYL5 (HY5) protein levels. The apocarotenoid signal and det1 complemented each other to restore POR levels and PLB formation, thereby controlling plastid development. Carotenoids are not just required as core components for plastid biogenesis, they can be cleaved into an apocarotenoid signal that regulates etioplast and chloroplast development during extended periods of darkness.
Smart Glass Film Reduced Ascorbic Acid in Red and Orange Capsicum Fruit Cultivars without Impacting Shelf Life
Publisher: MDPI AG
Date: 04-04-2022
Abstract: Smart Glass Film (SGF) is a glasshouse covering material designed to permit 80% transmission of photosynthetically active light and block heat-generating solar energy. SGF can reduce crop water and nutrient consumption and improve glasshouse energy use efficiency yet can reduce crop yield. The effect of SGF on the postharvest shelf life of fruits remains unknown. Two capsicum varieties, Red (Gina) and Orange (O06614), were cultivated within a glasshouse covered in SGF to assess fruit quality and shelf life during the winter season. SGF reduced cuticle thickness in the Red cultivar (5%) and decreased ascorbic acid in both cultivars (9–14%) without altering the overall morphology of the mature fruits. The ratio of total soluble solids (TSSs) to titratable acidity (TA) was significantly higher in Red (29%) and Orange (89%) cultivars grown under SGF. The Red fruits had a thicker cuticle that reduced water loss and extended shelf life when compared to the Orange fruits, yet neither water loss nor firmness were impacted by SGF. Reducing the storage temperature to 2 °C and increasing relative humidity to 90% extended the shelf life in both cultivars without evidence of chilling injury. In summary, SGF had minimal impact on fruit development and postharvest traits and did not compromise the shelf life of mature fruits. SGF provides a promising technology to block heat-generating solar radiation energy without affecting fruit ripening and marketable quality of capsicum fruits grown during the winter season.
Plant viral intergenic DNA sequence repeats with transcription enhancing activity
Publisher: Springer Science and Business Media LLC
Date: 2005
A novel cover material improves cooling energy and fertigation efficiency for glasshouse eggplant production
Publisher: Elsevier BV
Date: 07-2022
Establishment of an Arabidopsis callus system to study the interrelations of biosynthesis, degradation and accumulation of carotenoids
Publisher: Public Library of Science (PLoS)
Date: 02-02-2018
Abscisic acid supports colonization of Eucalyptus grandis roots by the mutualistic ectomycorrhizal fungus Pisolithus microcarpus
Publisher: Wiley
Date: 16-11-2022
DOI: 10.1111/NPH.17825
Abstract: The pathways regulated in ectomycorrhizal (EcM) plant hosts during the establishment of symbiosis are not as well understood when compared to the functional stages of this mutualistic interaction. Our study used the EcM host Eucalyptus grandis to elucidate symbiosis‐regulated pathways across the three phases of this interaction. Using a combination of RNA sequencing and metabolomics we studied both stage‐specific and core responses of E. grandis during colonization by Pisolithus microcarpus . Using exogenous manipulation of the abscisic acid (ABA), we studied the role of this pathway during symbiosis establishment. Despite the mutualistic nature of this symbiosis, a large number of disease signalling TIR‐NBS‐LRR genes were induced. The transcriptional regulation in E. grandis was found to be dynamic across colonization with a small core of genes consistently regulated at all stages. Genes associated to the carotenoid/ABA pathway were found within this core and ABA concentrations increased during fungal integration into the root. Supplementation of ABA led to improved accommodation of P. microcarpus into E. grandis roots. The carotenoid pathway is a core response of an EcM host to its symbiont and highlights the need to understand the role of the stress hormone ABA in controlling host–EcM fungal interactions.
Tangerine tomato roots show increased accumulation of acyclic carotenoids, less abscisic acid, drought sensitivity, and impaired endomycorrhizal colonization
Publisher: Elsevier BV
Date: 08-2022
DOI: 10.1016/J.PLANTSCI.2022.111308
Abstract: The Heirloom Golden tangerine tomato fruit variety is highly nutritious due to accumulation of tetra-cis-lycopene, that has a higher bioavailability and recognised health benefits in treating anti-inflammatory diseases compared to all-trans-lycopene isomers found in red tomatoes. We investigated if photoisomerization of tetra-cis-lycopene occurs in roots of the MicroTom tangerine (tang
Towards the production of transgenic pineapple to control flowering and ripening
Publisher: International Society for Horticultural Science (ISHS)
Date: 05-2000
Analysis of RNA-mediated gene silencing using a new vector (pKNOCKOUT) and an in plantaAgrobacterium transient expression system
Publisher: Springer Science and Business Media LLC
Date: 12-2004
DOI: 10.1007/BF02772678
Prior exposure of Arabidopsis seedlings to mechanical stress heightens jasmonic acid-mediated defense against necrotrophic pathogens
Publisher: Springer Science and Business Media LLC
Date: 12-2020
DOI: 10.1186/S12870-020-02759-9
Abstract: Prolonged mechanical stress (MS) causes thigmomorphogenesis, a stress acclimation response associated with increased disease resistance. What remains unclear is if 1) plants pre-exposed to a short period of repetitive MS can prime defence responses upon subsequent challenge with necrotrophic pathogens, 2) MS mediates plant immunity via jasmonic acid (JA) signalling, and 3) a short period of repetitive MS can cause long-term changes in gene expression resembling a stress-induced memory. To address these points, 10-days old juvenile Arabidopsis seedlings were mechanically stressed for 7-days using a soft brush and subsequently challenged with the necrotrophic pathogens, Alternaria brassicicola, and Botrytis cinerea . Here we assessed how MS impacted structural cell wall appositions, disease symptoms and altered gene expression in response to infection. The MS-treated plants exhibited enhanced cell wall appositions and jasmonic acid (JA) accumulation that correlated with a reduction in disease progression compared to unstressed plants. The expression of genes involved in JA signalling, callose deposition, peroxidase and phytoalexin biosynthesis and reactive oxygen species detoxification were hyper-induced 4-days post-infection in MS-treated plants. The loss-of-function in JA signalling mediated by the JA-insensitive coronatine-insensitive 1 ( coi1 ) mutant impaired the hyper-induction of defense gene expression and promoted pathogen proliferation in MS-treated plants subject to infection. The basal expression level of PATHOGENESIS-RELATED GENE 1 and PLANT DEFENSIN 1.2 defense marker genes were constitutively upregulated in rosette leaves for 5-days post-MS, as well as in naïve cauline leaves that differentiated from the inflorescence meristem well after ceasing MS. This study reveals that exposure of juvenile Arabidopsis plants to a short repetitive period of MS can alter gene expression and prime plant resistance upon subsequent challenge with necrotrophic pathogens via the JA-mediated COI1 signalling pathway. MS may facilitate a stress-induced memory to modulate the plant’s response to future stress encounters. These data advance our understanding of how MS primes plant immunity against necrotrophic pathogens and how that could be utilised in sustainable agricultural practices.
Light-limited photosynthesis under energy-saving film decreases eggplant yield
Publisher: Wiley
Date: 29-08-2020
DOI: 10.1002/FES3.245
Carotenoid Biosynthesis and Regulation in Plants
Publisher: Wiley
Date: 12-01-2016
Effect of high light on canopy-level photosynthesis and leaf mesophyll ion flux in tomato
Publisher: Springer Science and Business Media LLC
Date: 09-10-2020
DOI: 10.1007/S00425-020-03493-0
Abstract: This study highlights the potential link between high light-induced canopy-level photosynthesis and mesophyll cell K
Potential implications for epigenetic regulation of carotenoid biosynthesis during root and shoot development
Publisher: Informa UK Limited
Date: 04-2009
DOI: 10.4161/PSB.4.4.8193
Flow restoration and the impacts of multiple stressors on fish communities in regulated rivers
Publisher: Wiley
Date: 31-05-2019
Contrasting effects of Miocene and Anthropocene levels of atmospheric CO 2 on silicon accumulation in a model grass
Publisher: The Royal Society
Date: 11-2020
Abstract: Grasses are hyper-accumulators of silicon (Si), which they acquire from the soil and deposit in tissues to resist environmental stresses. Given the high metabolic costs of herbivore defensive chemicals and structural constituents (e.g. cellulose), grasses may substitute Si for these components when carbon is limited. Indeed, high Si uptake grasses evolved in the Miocene when atmospheric CO 2 concentration was much lower than present levels. It is, however, unknown how pre-industrial CO 2 concentrations affect Si accumulation in grasses. Using Brachypodium distachyon , we hydroponically manipulated Si-supply (0.0, 0.5, 1, 1.5, 2 mM) and grew plants under Miocene (200 ppm) and Anthropocene levels of CO 2 comprising ambient (410 ppm) and elevated (640 ppm) CO 2 concentrations. We showed that regardless of Si treatments, the Miocene CO 2 levels increased foliar Si concentrations by 47% and 56% relative to plants grown under ambient and elevated CO 2 , respectively. This is owing to higher accumulation overall, but also the reallocation of Si from the roots into the shoots. Our results suggest that grasses may accumulate high Si concentrations in foliage when carbon is less available (i.e. pre-industrial CO 2 levels) but this is likely to decline under future climate change scenarios, potentially leaving grasses more susceptible to environmental stresses.
Role of the Arabidopsis PIN6 Auxin Transporter in Auxin Homeostasis and Auxin-Mediated Development
Publisher: Public Library of Science (PLoS)
Date: 29-07-2013
Environmental impacts on carotenoid metabolism in leaves
Publisher: Springer Science and Business Media LLC
Date: 07-09-2020
An energy-saving glasshouse film reduces seasonal, and cultivar dependent Capsicum yield due to light limited photosynthesis
Publisher: Cold Spring Harbor Laboratory
Date: 31-10-2022
DOI: 10.1101/2022.10.29.513818
Abstract: Glasshouse films can be used to reduce energy costs by limiting non-productive heat-generating radiation, but the impact on yield of greenhouse horticultural crops remains unknown. The effects of energy-saving film ULR-80 (referred to as Smart Glass SG) designed to block long wavelength light that generates heat also reduced photosynthetically active radiation (PAR) consequently affecting crop morphology, photosynthesis, leaf pigments, and yield of two hydroponically grown capsicum ( Capsicum annuum L.) cultivars (Red and Orange). The crops were grown in four high-tech glasshouse bays over two seasons of similar daily light integrals (DLI) during ascending (Autumn) and descending (Summer) photoperiods. The Red cultivar exhibited higher photosynthetic rates (light saturated - A sat and maximal - A max ) and yield than the Orange cultivar in control but displayed stronger reductions in modelled photosynthetic rates at growth light and yield in SG without changes in photosynthetic capacity. Foliar pigment ratios of chlorophyll a/b and carotenoid: chlorophyll remained unaffected by the SG during both seasons indicating that chloroplast homeostasis was similar between SG and control. The seasonal differences in photosynthetic pigments and xanthophyll de-epoxidation state (DPS) revealed that cultivars were able to sense the SG-altered light environment during the ascending, but not descending photoperiod. The descending photoperiod correlated with a lower daily light level and a substantial yield reduction of 29 % and 13 % in Red and Orange cultivars, respectively. Thus, SG-induced higher reductions in yield during the descending photoperiod indicate that SG may be more beneficial for capsicum crops planted during Autumn with an ascending photoperiod. A potential energy saving SG film limited net photosynthesis of capsicum The SG film reduced yield of two capsicum cultivars that can be mitigated by planting during the low light growth season with a shorter photoperiod SG reduced genotype-dependent capsicum yield was associated with alterations in the level of foliar pigments required for photoprotection under adverse light conditions
Inflorescence stem grafting made easy in Arabidopsis
Publisher: Springer Science and Business Media LLC
Date: 12-2012
Abstract: Plant grafting techniques have deepened our understanding of the signals facilitating communication between the root and shoot, as well as between shoot and reproductive organs. Transmissible signalling molecules can include hormones, peptides, proteins and metabolites: some of which travel long distances to communicate stress, nutrient status, disease and developmental events. While hypocotyl micrografting techniques have been successfully established for Arabidopsis to explore root to shoot communications, inflorescence grafting in Arabidopsis has not been exploited to the same extent. Two different strategies (horizontal and wedge-style inflorescence grafting) have been developed to explore long distance signalling between the shoot and reproductive organs. We developed a robust wedge-cleft grafting method, with success rates greater than 87%, by developing better tissue contact between the stems from the inflorescence scion and rootstock. We describe how to perform a successful inflorescence stem graft that allows for reproducible translocation experiments into the physiological, developmental and molecular aspects of long distance signalling events that promote reproduction. Wedge grafts of the Arabidopsis inflorescence stem were supported with silicone tubing and further sealed with parafilm to maintain the vascular flow of nutrients to the shoot and reproductive tissues. Nearly all (87%) grafted plants formed a strong union between the scion and rootstock. The success of grafting was scored using an inflorescence growth assay based upon the growth of primary stem. Repeated pruning produced new cauline tissues, healthy flowers and reproductive siliques, which indicates a healthy flow of nutrients from the rootstock. Removal of the silicone tubing showed a tightly fused wedge graft junction with callus proliferation. Histological staining of sections through the graft junction demonstrated the differentiation of newly formed vascular connections, parenchyma tissue and lignin accumulation, supporting the presumed success of the graft union between two sections of the primary inflorescence stem. We describe a simple and reliable method for grafting sections of an Arabidopsis inflorescence stem. This step-by-step protocol facilitates laboratories without grafting experience to further explore the molecular and chemical signalling which coordinates communications between the shoot and reproductive tissues.
A chloroplast retrograde signal, 3’phosphoadenosine 5’-phosphate, acts as a secondary messenger in abscisic acid signaling in stomatal closure and germination
Publisher: eLife Sciences Publications, Ltd
Date: 21-03-2017
DOI: 10.7554/ELIFE.23361
Abstract: Organelle-nuclear retrograde signaling regulates gene expression, but its roles in specialized cells and integration with hormonal signaling remain enigmatic. Here we show that the SAL1-PAP (3′-phosphoadenosine 5′- phosphate) retrograde pathway interacts with abscisic acid (ABA) signaling to regulate stomatal closure and seed germination in Arabidopsis. Genetically or exogenously manipulating PAP bypasses the canonical signaling components ABA Insensitive 1 (ABI1) and Open Stomata 1 (OST1) priming an alternative pathway that restores ABA-responsive gene expression, ROS bursts, ion channel function, stomatal closure and drought tolerance in ost1-2. PAP also inhibits wild type and abi1-1 seed germination by enhancing ABA sensitivity. PAP-XRN signaling interacts with ABA, ROS and Ca2+ up-regulating multiple ABA signaling components, including lowly-expressed Calcium Dependent Protein Kinases (CDPKs) capable of activating the anion channel SLAC1. Thus, PAP exhibits many secondary messenger attributes and exemplifies how retrograde signals can have broader roles in hormone signaling, allowing chloroplasts to fine-tune physiological responses.
Short‐term resistance that persists: Rapidly induced silicon anti‐herbivore defence affects carbon‐based plant defences
Publisher: Wiley
Date: 28-10-2020
A chromatin modifying enzyme, SDG8, is involved in morphological, gene expression, and epigenetic responses to mechanical stimulation
Publisher: Frontiers Media SA
Date: 21-10-2014
Short photoperiod attenuates CO 2 fertilization effect on shoot biomass in Arabidopsis thaliana .
Publisher: Springer Science and Business Media LLC
Date: 16-03-2021
Short‐term exposure to silicon rapidly enhances plant resistance to herbivory
Publisher: Wiley
Date: 26-07-2021
DOI: 10.1002/ECY.3438
Abstract: Silicon (Si) can adversely affect insect herbivores, particularly in plants that evolved the ability to accumulate large quantities of Si. Very rapid herbivore‐induced accumulation of Si has recently been demonstrated, but the level of protection against herbivory this affords plants remains unknown. Brachypodium distachyon , a model Si hyperaccumulating grass, was exposed to the chewing herbivore, Helicoverpa armigera, and grown under three conditions: supplied Si over 34 d (+Si), not supplied Si (−Si), or supplied Si once herbivory began (−Si → +Si). We evaluated the effectiveness of each Si treatment at reducing herbivore performance and measured Si‐based defenses and phenolics (another form of defense often reduced by Si). Although Si concentrations remained lower, within 72 h of exposure to Si, −Si → +Si plants were as resistant to herbivory as +Si plants. Both +Si and −Si → +Si treatments reduced herbivore damage and growth, and increased mandible wear compared to −Si. After 6 h, herbivory increased filled Si cell density in −Si → +Si plants, and within 24 h, −Si → +Si plants reached similar filled Si cell densities to +Si plants, although decreased phenolics only occurred in +Si plants. We demonstrate that plants with short‐term Si exposure can rapidly accumulate Si‐based antiherbivore defenses as effectively as plants with long‐term exposure.
Construction and testing of an intron-containing luciferase reporter gene fromRenilla reniformis
Publisher: Springer Science and Business Media LLC
Date: 09-2003
DOI: 10.1007/BF02772802
Biosynthesis and regulation of carotenoids in plants - Micronutrients, vitamins and health benefits
Publisher: Springer Berlin Heidelberg
Date: 2010
Anti‐herbivore silicon defences in a model grass are greatest under Miocene levels of atmospheric CO 2
Publisher: Wiley
Date: 14-04-2021
DOI: 10.1111/GCB.15619
Microbes in Helicoverpa armigera oral secretions contribute to increased senescence around plant wounds
Publisher: Wiley
Date: 11-05-2020
DOI: 10.1111/EEN.12886
Precise Phenotyping for Improved Crop Quality and Management in Protected Cropping: A Review
Publisher: MDPI AG
Date: 22-09-2022
DOI: 10.3390/CROPS2040024
Abstract: Protected cropping produces more food per land area than field-grown crops. Protected cropping includes low-tech polytunnels utilizing protective coverings, medium-tech facilities with some environmental control, and high-tech facilities such as fully automated glasshouses and indoor vertical farms. High crop productivity and quality are maintained by using environmental control systems and advanced precision phenotyping sensor technologies that were first developed for broadacre agricultural and can now be utilized for protected-cropping applications. This paper reviews the state of the global protected-cropping industry and current precision phenotyping methodology and technology that is used or can be used to advance crop productivity and quality in a protected growth environment. This review assesses various sensor technologies that can monitor and maintain microclimate parameters, as well as be used to assess plant productivity and produce quality. The adoption of precision phenotyping technologies is required for sustaining future food security and enhancing nutritional quality.
Precision Pollination Strategies for Advancing Horticultural Tomato Crop Production
Publisher: MDPI AG
Date: 18-02-2022
Abstract: Global climate change and anthropological activities have led to a decline in insect pollinators worldwide. Agricultural globalisation and intensification have also removed crops from their natural insect pollinators, and sparked research to identify alternate natural insect pollinators and artificial technologies. In certain countries such as Australia the importation of commercial insect pollinators is prohibited, necessitating manual labour to stimulate floral pollination. Artificial pollination technologies are now increasingly essential as the demand for food grown in protected facilities increases worldwide. For tomato fruits, precision pollination has the ability to vastly improve their seed set, size, yield, and quality under optimal environmental conditions and has become financially beneficial. Like many crops from the Solanaceae, tomatoes have a unique self-pollinating mechanism that requires stimulation of the floral organs to release pollen from the poricidal anthers. This review investigates various mechanisms employed to pollinate tomato flowers and discusses emerging precision pollination technologies. The advantages and disadvantages of various pollinating technologies currently available in the protected-cropping industry are described. We provide a buzz perspective on new promising pollination technologies involving robotic air and acoustic devices that are still in their nascency and could provide non-contact techniques to automate pollination for the tomato horticultural industry.
Functional characterization of the geminiviral conserved late element (CLE) in uninfected tobacco
Publisher: Springer Science and Business Media LLC
Date: 07-2005
DOI: 10.1007/S11103-005-6589-X
Abstract: The conserved late element (CLE) was originally identified as an evolutionarily conserved DNA sequence present in geminiviral intergenic regions. CLE has subsequently been observed in promoter sequences of bacterial (T-DNA) and plant origin, suggesting a role in plant and plant viral gene regulation. Synthetic DNA cassettes harboring direct repeats of the CLE motif were placed upstream from a -46 to +1 minimal CaMV 35S promoter-luciferase reporter gene and reporter activity characterized in Nicotiana species during both transient and stable expression. A single direct-repeat cassette of the element (2x CLE) enhances luciferase activity by 2-fold, independent of the element's orientation, while multiple copies of the cassette (4-12x CLE) increases activity up to 10- to 15-fold in an additive manner. Transgenic tobacco lines containing synthetic CLE promoter constructs enhance luciferase expression in leaf, cotyledon and stem tissues, but to a lesser extent in roots. Single nucleotide substitution at six of eight positions within the CLE consensus (GTGGTCCC) eliminates CLE enhancer-like activity. It has been previously reported that CLE interacts with the AC2 protein from Pepper Huasteco Virus (PHV-AC2). PHV-AC2 (also called AL2 or C2) is a member of the transcriptional activator protein, or TrAP, gene family. In transient and stable expression systems PHV-AC2 expression was found to result in a 2-fold increase in luciferase activity, irrespective of the presence of CLE consensus sequences within the reporter's promoter. These data suggests that the PHV-AC2 protein, instead of interacting directly with CLE, functions as either a general transcriptional activator and/or a suppressor of post-transcriptional gene silencing.
Related Organisations
USDA Agricultural Research Service
Location: United States of America
Related Funding Activities
National Tree Genomics Program
Start Date: 2019
End Date: 2022
Funder: Hort Innovation
View Funded ActivityResearch And Operations To Trial Innovation Glass And Photovoltaic Technologies In Protected Cropping
Start Date: 2017
End Date: 2021
Funder: Hort Innovation
View Funded ActivityGlasshouse Films To Reduce Energy Use And Increase Resource Use Efficiency
Start Date: 2022
End Date: 2027
Funder: Future Food Systems Cooperative Research Centre
View Funded ActivityThe Hunt For RNA Riboswitches And Genetic Sensors Of Metabolic Flux In Plants
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End Date: 2016
Funder: Australian Research Council
View Funded ActivityCooperative Research Centre In Future Food Systems
Start Date: 2019
End Date: 2029
Funder: Department of Industry, Innovation and Science, Australian Government
View Funded ActivityLinkage Infrastructure, Equipment And Facilities - Grant ID: LE0989589
Start Date: 2009
End Date: 06-2009
Amount: $550,000.00
Funder: Australian Research Council
View Funded ActivityDiscovery Projects - Grant ID: DP130102593
Start Date: 06-2013
End Date: 12-2017
Amount: $375,000.00
Funder: Australian Research Council
View Funded Activity