Ed Newbigin

RNase-based self-incompatibility: Puzzled by Pollen S

Publisher: Oxford University Press (OUP)

Date: 09-2008

DOI: 10.1105/TPC.108.060327

Abstract: Many plants have a genetically determined self-incompatibility system in which the rejection of self pollen grains is controlled by alleles of an S locus. A common feature of these S loci is that separate pollen- and style-expressed genes (pollen S and style S, respectively) determine S allele identity. The long-held view has been that pollen S and style S must be a coevolving gene pair in order for allelic recognition to be maintained as new S alleles arise. In at least three plant families, the Solanaceae, Rosaceae, and Plantaginaceae, the style S gene has long been known to encode an extracellular ribonuclease called the S-RNase. Pollen S in these families has more recently been identified and encodes an F-box protein known as either SLF or SFB. In this perspective, we describe the puzzling evolutionary relationship that exists between the SLF/SFB and S-RNase genes and show that in most cases cognate pairs of genes are not coevolving in the expected manner. Because some pollen S genes appear to have arisen much more recently than their style S cognates, we conclude that either some pollen S genes have been falsely identified or that there is a major problem with our understanding of how the S locus evolves.

Model-based analysis of the likelihood of gene introgression from genetically modified crops into wild relatives

Publisher: Elsevier BV

Date: 04-2003

DOI: 10.1016/S0304-3800(02)00347-2

The AusPollen partnership project

Publisher: Elsevier BV

Date: 11-2022

DOI: 10.1016/J.ENVRES.2022.113762

Abstract: Allergic rhinitis affects half a billion people globally, including a fifth of the Australian population. As the foremost outdoor allergen source, ambient grass pollen exposure is likely to be altered by climate change. The AusPollen Partnership aimed to standardize pollen monitoring and examine broad-scale biogeographical and meteorological factors influencing interannual variation in seasonality of grass pollen aerobiology in Australia. Daily airborne grass and other pollen concentrations in four eastern Australian cities separated by over 1700 km, were simultaneously monitored using Hirst-style s lers following the Australian Interim Pollen and Spore Monitoring Standard and Protocols over four seasons from 2016 to 2020. The grass seasonal pollen integral was determined. Gridded rainfall, temperature, and satellite-derived grassland sources up to 100 km from the monitoring site were analysed. The complexity of grass pollen seasons was related to latitude with multiple major summer-autumn peaks in Brisbane, major spring and minor summer peaks in Sydney and Canberra, and single major spring peaks occurring in Melbourne. The subtropical site of Brisbane showed a higher proportion of grass out of total pollen than more temperate sites. The magnitude of the grass seasonal pollen integral was correlated with pasture greenness, rainfall and number of days over 30 °C, preceding and within the season, up to 100 km radii from monitoring sites. Interannual fluctuations in Australian grass pollen season magnitude are strongly influenced by regional biogeography and both pre- and in-season weather. This first continental scale, Southern Hemisphere standardized aerobiology dataset forms the basis to track shifts in pollen seasonality, bio ersity and impacts on allergic respiratory diseases.

Comparative morphology and phylogeny of Nicotiana section Suaveolentes (Solanaceae) in Australia and the South Pacific

Publisher: CSIRO Publishing

Date: 2011

DOI: 10.1071/SB11006

Abstract: Molecular phylogenies alone have failed to resolve evolutionary relationships of Nicotiana L. section Suaveolentes Goodsp. (Solanaceae), a section largely comprising Australian endemics. Comparative morphology of Suaveolentes is illustrated and characters, together with the chromosome number, coded for phylogenetic analysis. Morphological characters included discrete characters of seeds and trichomes studied by scanning electron and light microscopy, and gap-coded quantitative measurements of flowers and vegetative organs. These data were analysed using both maximum parsimony and splits network, and compared to and combined with molecular analyses based on published nuclear and chloroplast-DNA sequences. Among morphological characters, there was a high level of homoplasy, possibly attributable to convergent evolution, hybridisation and introgression, and the underlying polyploid origin of the group. There was some conflict between the morphological and molecular datasets however, overall there was a level of concordance that identified a phylogenetic sequence of taxa that reflected a reduction in the chromosome number. With N. africana as the functional outgroup, analyses showed N. fragrans (New Caledonia and Tongatapu) and N. fatuhivensis (Marquesas islands, formerly N. fragrans var. fatuhivensis) to be a basal lineage in the Australian and South Pacific clade of Suaveolentes. N. forsteri (eastern mainland Australia, Lord Howe Island and New Caledonia) is the sister taxon to all other Australian species of Suaveolentes, which form a well supported monophyletic group. Within this Australian endemic group, species with a chromosome count of n = 24 or 23 are early lineages. Two clades with a reduced chromosome number are the ‘N. simulans clade’ (all taxa with n = 20) and the ‘N. suaveolens clade’ (n = 19, 18, 16, or 15). The position of N. cavicola (n = 20 or 23) is equivocal, and it and several other species require further study. Some widespread taxa require greater s ling of populations to test for variation in morphology, DNA sequences and chromosome number for further elucidation of the evolutionary history of Suaveolentes.

Transgenic tobacco plants which express the chiA gene from Serratia marcescens have enhanced tolerance to Rhizoctonia solani

Publisher: Springer Science and Business Media LLC

Date: 03-1994

DOI: 10.1007/BF01974086

Temporal and spatial appearance of wall polysaccharides during cellularization of barley (Hordeum vulgare) endosperm

Publisher: Springer Science and Business Media LLC

Date: 11-03-2006

DOI: 10.1007/S00425-006-0244-X

Abstract: Barley endosperm begins development as a syncytium where numerous nuclei line the perimeter of a large vacuolated central cell. Between 3 and 6 days after pollination (DAP) the multinucleate syncytium is cellularized by the centripetal synthesis of cell walls at the interfaces of nuclear cytoplasmic domains between in idual nuclei. Here we report the temporal and spatial appearance of key polysaccharides in the cell walls of early developing endosperm of barley, prior to aleurone differentiation. Flowering spikes of barley plants grown under controlled glasshouse conditions were hand-pollinated and the developing grains collected from 3 to 8 DAP. Barley endosperm development was followed at the light and electron microscope levels with monoclonal antibodies specific for (1-->3)-beta-D: -glucan (callose), (1-->3,1-->4)-beta-D: -glucan, hetero-(1-->4)-beta-D: -mannans, arabino-(1-->4)-beta-D: -xylans, arabinogalactan-proteins (AGPs) and with the enzyme, cellobiohydrolase II, to detect (1-->4)-beta-D: -glucan (cellulose). Callose and cellulose were present in the first formed cell walls between 3 and 4 DAP. However, the presence of callose in the endosperm walls was transient and at 6 DAP was only detected in collars surrounding plasmodesmata. (1-->3,1-->4)-beta-D: -Glucan was not deposited in the developing cell walls until approximately 5 DAP and hetero-(1-->4)-beta-D: -mannans followed at 6 DAP. Deposition of AGPs and arabinoxylan in the wall began at 7 and 8 DAP, respectively. For arabinoxylans, there is a possibility that they are deposited earlier in a highly substituted form that is inaccessible to the antibody. Arabinoxylan and heteromannan were also detected in Golgi and associated vesicles in the cytoplasm. In contrast, (1-->3,1-->4)-beta-D: -glucan was not detected in the cytoplasm in endosperm cells similar results were obtained for coleoptile and suspension cultured cells.

Mutational approaches to the study of self-incompatibility: Revisiting the pollen-part mutants

Publisher: Oxford University Press (OUP)

Date: 03-2000

DOI: 10.1006/ANBO.1999.1060

Genetic analysis of Nicotiana pollen-part mutants is consistent with the presence of an S-ribonuclease inhibitor at the S locus.

Publisher: Proceedings of the National Academy of Sciences

Date: 18-12-2001

DOI: 10.1073/PNAS.261571598

Abstract: Self-incompatibility (SI) is a genetic mechanism that restricts inbreeding in flowering plants. In the nightshade family (Solanaceae) SI is controlled by a single multiallelic S locus. Pollen rejection in this system requires the interaction of two S locus products: a stylar (S)-RNase and its pollen counterpart (pollen S). pollen S has not yet been cloned. Our understanding of how this gene functions comes from studies of plants with mutations that affect the pollen but not the stylar SI response (pollen-part mutations). These mutations are frequently associated with duplicated S alleles, but the absence of an obvious additional allele in some plants suggests pollen S can also be deleted. We studied Nicotiana alata plants with an additional S allele and show that duplication causes a pollen-part mutation in several different genetic backgrounds. Inheritance of the duplication was consistent with a competitive interaction model in which any two nonmatching S alleles cause a breakdown of SI when present in the same pollen grain. We also examined plants with presumed deletions of pollen S and found that they instead have duplications that included pollen S but not the S-RNase gene. This finding is consistent with a bipartite structure for the S locus. The absence of pollen S deletions in this study and perhaps other studies suggests that pollen S might be required for pollen viability, possibly because its product acts as an S-RNase inhibitor.

Characterization of Rny1, the Saccharomyces cerevisiae member of the T2 RNase family of RNases: Unexpected functions for ancient enzymes?

Publisher: Proceedings of the National Academy of Sciences

Date: 30-01-2001

DOI: 10.1073/PNAS.98.3.1018

Abstract: The T 2 family of nonspecific endoribonucleases (EC 3.1.27.1 ) is a widespread family of RNases found in every organism examined thus far. Most T 2 enzymes are secretory RNases and therefore are found extracellularly or in compartments of the endomembrane system that would minimize their contact with cellular RNA. Although the biological functions of various T 2 RNases have been postulated on the basis of enzyme location or gene expression patterns, the cellular roles of these enzymes are generally unknown. In the present work, we characterized Rny1, the only T 2 RNase in Saccharomyces cerevisiae . Rny1 was found to be an active, secreted RNase whose gene expression is controlled by heat shock and osmotic stress. Inactivation of RNY1 leads to unusually large cells that are temperature-sensitive for growth. These phenotypes can be complemented not only by RNY1 but also by both structurally related and unrelated secretory RNases. Additionally, the complementation depends on RNase activity. When coupled with a recent report on the effect of specific RNAs on membrane permeability [Khvorova, A., Kwak, Y-G., Tamkun, M., Majerfeld, I. & Yarus, M. (1999) Proc. Natl. Acad. Sci. USA 96, 10649–10654], our work suggests an unexpected role for Rny1 and possibly other secretory RNases. These enzymes may regulate membrane permeability or stability, a hypothesis that could present an alternative perspective for understanding their functions.

Regional and seasonal variation in airborne grass pollen levels between cities of Australia and New Zealand

Publisher: Springer Science and Business Media LLC

Date: 29-07-2016

DOI: 10.1007/S10453-015-9399-X

Evaluation of the performance of short-term curated daily airborne grass pollen forecasts in diverse biogeographical regions during the AusPollen Partnership project 2016–2020

Publisher: Elsevier BV

Date: 10-2022

DOI: 10.1016/J.AEAOA.2022.100183

Associations between outdoor fungal spores and childhood and adolescent asthma hospitalizations

Publisher: Elsevier BV

Date: 04-2017

DOI: 10.1016/J.JACI.2016.06.046

Abstract: Childhood asthma is a significant public health problem and severe exacerbations can result in diminished quality of life and hospitalization. We sought to examine the contribution of outdoor fungi to childhood and adolescent asthma hospitalizations. The Melbourne Air Pollen Children and Adolescent study is a case-crossover study of 644 children and adolescents (aged 2-17 years) hospitalized for asthma. The Melbourne Air Pollen Children and Adolescent study collected in idual data on human rhinovirus infection and sensitization to Alternaria and Cladosporium and daily counts of ambient concentrations of fungal spores, pollen, and air pollutants. Conditional logistic regression models were used to assess associations with increases in spore counts while controlling for potential confounding and testing interactions. Exposure to Alternaria (adjusted odds ratio [aOR], 1.07 95% CI, 1.03-1.11), Leptosphaeria (aOR, 1.05 95% CI, 1.02-1.07), Coprinus (aOR, 1.04 95% CI, 1.01-1.07), Drechslera (aOR, 1.03 95% CI, 1.00-1.05), and total spores (aOR, 1.05 95% CI, 1.01-1.09) was significantly associated with child asthma hospitalizations independent of human rhinovirus infection. There were significant lagged effects up to 3 days with Alternaria, Leptosphaeria, Cladosporium, Sporormiella, Coprinus, and Drechslera. Some of these associations were significantly greater in participants with Cladosporium sensitization. Exposures to several outdoor fungal spore taxa, including some not reported in previous research, are associated with the risk of child and adolescent asthma hospitalization, particularly in in iduals sensitized to Cladosporium. We need further studies to examine cross-reactivity causing asthma exacerbations. Identifying sensitization to multiple fungal allergens in children with asthma could support the design and implementation of more effective strategies to prevent asthma exacerbations.

Modelling atmospheric concentrations of grass pollen using meteorological variables in Melbourne, Australia.

Publisher: Informa UK Limited

Date: 10-2007

DOI: 10.1080/09603120701628693

Abstract: This study aims to develop models that may be used to describe the relationship between meteorological variables and ambient concentrations of pollen. We used daily ambient concentrations of grass pollen during the pollen season (October to December) of 2004 in Melbourne, Australia. During this period, daily levels of meteorological data including average relative humidity, mean temperature, rain fall, wind speed, and wind direction were entered as predictors in the models. A generalized additive model (GAM) was used to assess the relationship between daily levels of meteorological variables and ambient concentrations of grass pollen. The relationship between average temperature, rain fall, wind speed, relative humidity and pollen were nonlinear and smooth terms were highly significant (p < 0.001). Nonlinear statistical methods such as the GAM approach have the potential to accurately predict ambient concentrations of pollen during the pollen season.

A retrotransposon-like sequence linked to the S-locus of

Publisher: Springer Science and Business Media LLC

Date: 1996

DOI: 10.1007/S004380050065

The macroecology of airborne pollen in Australian and New Zealand urban areas

Publisher: Public Library of Science (PLoS)

Date: 29-05-2014

DOI: 10.1371/JOURNAL.PONE.0097925

The sequence of a pea vicilin gene and its expression in transgenic tobacco plants.

Publisher: Springer Science and Business Media LLC

Date: 1988

DOI: 10.1007/BF00017468

Differences in grass pollen allergen exposure across Australia

Publisher: Elsevier BV

Date: 02-2015

DOI: 10.1111/1753-6405.12325

A genetic map of the Nicotiana alata S locus that includes three pollen-expressed genes

Publisher: Springer Science and Business Media LLC

Date: 04-2000

DOI: 10.1007/S001220051376

Molecular control of the glucan synthase-like protein NaGSL1 and callose synthesis during growth of Nicotiana alata pollen tubes

Publisher: Portland Press Ltd.

Date: 29-07-2008

DOI: 10.1042/BJ20080693

Abstract: The protein NaGSL1 (Nicotiana alata glucan synthase-like 1) is implicated in the synthesis of callose, the 1,3-β-glucan that is the major polysaccharide in the walls of N. alata (flowering tobacco) pollen tubes. Here we examine the production, intracellular location and post-translational processing of NaGSL1, and relate each of these to the control of pollen-tube callose synthase (CalS). The 220 kDa NaGSL1 polypeptide is produced after pollen-tube germination and accumulates during pollen-tube growth, as does CalS. A combination of membrane fractionation and immunoelectron microscopy revealed that NaGSL1 was present predominantly in the endoplasmic reticulum and Golgi membranes in younger pollen tubes when CalS was mostly in an inactive (latent) form. In later stages of pollen-tube growth, when CalS was present in both latent and active forms, a greater proportion of NaGSL1 was in intracellular vesicles and the plasma membrane, the latter location being consistent with direct deposition of callose into the wall. N. alata CalS is activated in vitro by the proteolytic enzyme trypsin and the detergent CHAPS, but in neither case was activation associated with a detectable change in the molecular mass of the NaGSL1 polypeptide. NaGSL1 may thus either be activated by the removal of a few amino acids or by the removal of another protein that inhibits NaGSL1. These findings are discussed in relation to the control of callose biosynthesis during pollen germination and pollen-tube growth.

The evolutionary dynamics of self-incompatibility systems

Publisher: Elsevier BV

Date: 09-2005

DOI: 10.1016/J.TIG.2005.07.003

Abstract: Self-incompatible flowering plants reject pollen that expresses the same mating specificity as the pistil (female reproductive tract). In most plant families, pollen and pistil mating specificities segregate as a single locus, the S locus. In at least two self-incompatibility systems, distinct pollen and pistil specificity genes are embedded in an extensive nonrecombining tract. To facilitate consideration of how new S locus specificities arise in systems with distinct pollen and pistil genes, we present a graphical model for the generation of hypotheses. It incorporates the evolutionary principle that nonreciprocal siring success (cross-pollinations between two plants produce seeds in only one direction) tends to favor the rejecting partner. This model suggests that selection within S-allele specificity classes could accelerate the rate of nonsynonymous (amino acid-changing) substitutions, with periodic selective sweeps removing segregating variation within classes. Accelerated substitution within specificity classes could also promote the origin of new S-allele specificities.

The role of seasonal grass pollen on childhood asthma emergency department presentations

Publisher: Wiley

Date: 20-04-2012

DOI: 10.1111/J.1365-2222.2012.03995.X

Abstract: Few studies have focused on the role of grass pollen on asthma emergency department (ED) presentations among children. None have examined whether a dose-response effect exists between grass pollen levels and these asthma exacerbations. To examine the association between increasing ambient levels of grass pollen and asthma ED presentations in children. To determine whether these associations are seen only after a thunderstorm, or whether grass pollen levels have a consistent influence on childhood asthma ED visits during the season. A short time series ecological study was conducted for asthma presentations to ED among children in Melbourne, Victoria, and grass pollen, meteorological and air quality measurements recorded during the selected 2003 period. A semi-parametric Poisson regression model was used to examine dose-response associations between daily grass pollen levels and mean daily ED attendance for asthma. A smoothed plot suggested a dose-response association. As ambient grass pollen increased to about 19 grains/m(3) , the same day risk of childhood ED presentations also increased linearly (P < 0.001). Grass pollen levels were also associated with an increased risk in asthma ED presentations on the following day (lag 1, P < 0.001). This is the first study to establish a clear relationship between increased risk of childhood asthma ED attendance and levels of ambient grass pollen below 20 grains/m(3) , independent of any impact of thunderstorm-associated asthma. These findings have important implications for patient care, such as asthma management programs that notify the general public regarding periods of high grass pollen exposure, as well as defining the timing of initiation of pollen immunotherapy.

Do human rhinovirus infections and food allergy modify grass pollen-induced asthma hospital admissions in children?

Publisher: Elsevier BV

Date: 10-2015

DOI: 10.1016/J.JACI.2015.04.030

Glycoprotein E2 of classical swine fever virus: Expression in insect cells and identification as a ribonuclease

Publisher: Elsevier BV

Date: 05-1994

DOI: 10.1006/VIRO.1994.1218

Abstract: Two regions of amino acids homologous to the ribonuclease catalysis domain of the fungal RNases T2 of Aspergillus oryzae and Rh of Rhizopus niveus and the plant S-glycoproteins of Nicotiana alata are perfectly conserved in the amino acid sequence of the envelope glycoprotein E2 of classical swine fever virus (CSFV). To analyze the functional significance of these conserved sequences, the gene encoding E2 was inserted into the p10 locus of baculovirus and expressed in insect cells. Recombinant virus BacCE2 generated a protein which was similar in size (42 to 46 kDa) to wild-type E2 synthesized in swine kidney cells infected with CSFV. Recombinant E2 was purified by immunoaffinity chromatography from the lysate of cells infected with BacCE2 and assayed for RNase activity. RNase activity coeluted with the E2 fraction, indicating that ribonuclease activity is an inherent property of E2. The ribonuclease-specific activity of the protein fraction containing pure E2 was comparable to that of the N. alata S-glycoproteins.

A Glycosyltransferase from Nicotiana alata Pollen Mediates Synthesis of a Linear (1,5)-α-L-Arabinan When Expressed in Arabidopsis

Publisher: Oxford University Press (OUP)

Date: 05-02-2016

DOI: 10.1104/PP.15.02005

Callose and its role in pollen and embryo sac development in flowering plants

Publisher: Elsevier

Date: 2009

DOI: 10.1016/B978-0-12-373971-1.00014-5

Patterns of Variation Within Self-Incompatibility Loci

Publisher: Oxford University Press (OUP)

Date: 27-06-2003

DOI: 10.1093/MOLBEV/MSG209

On the causes of variability in amounts of airborne grass pollen in Melbourne, Australia

Publisher: Springer Science and Business Media LLC

Date: 04-09-2011

DOI: 10.1007/S00484-010-0361-X

Abstract: In Melbourne, Australia, airborne grass pollen is the predominant cause of hay fever (seasonal rhinitis) during late spring and early summer, with levels of airborne grass pollen also influencing hospital admissions for asthma. In order to improve predictions of conditions that are potentially hazardous to susceptible in iduals, we have sought to better understand the causes of diurnal, intra-seasonal and inter-seasonal variability of atmospheric grass pollen concentrations (APC) by analysing grass pollen count data for Melbourne for 16 grass pollen seasons from 1991 to 2008 (except 1994 and 1995). Some of notable features identified in this analysis were that on days when either extreme (>100 pollen grains m(-3)) or high (50-100 pollen grains m(-3)) levels of grass pollen were recorded the winds were of continental origin. In contrast, on days with a low ( 100 pollen grains m(-3)) during the study period were characterised by an average downward vertical wind anomaly in the surface boundary layer over Melbourne. Together these findings form a basis for a fine resolution atmospheric general circulation model for grass pollen in Melbourne's air that can be used to predict daily (and hourly) APC. This information will be useful to those sectors of Melbourne's population that suffer from allergic problems.

Pea convicilin: structure and primary sequence of the protein and expression of a gene in the seeds of transgenic tobacco

Publisher: Springer Science and Business Media LLC

Date: 03-1989

DOI: 10.1007/BF02411442

Proteomic and biochemical evidence links the callose synthase in Nicotiana alata pollen tubes to the product of the NaGSL1 gene

Publisher: Wiley

Date: 25-07-2007

DOI: 10.1111/J.1365-313X.2007.03219.X

Tom22', an 8-kDa trans-Site Receptor in Plants and Protozoans, Is a Conserved Feature of the TOM Complex That Appeared Early in the Evolution of Eukaryotes

Publisher: Oxford University Press (OUP)

Date: 12-02-2004

DOI: 10.1093/MOLBEV/MSH166

Pollen tubes of Nicotiana alata express two genes from different β-glucan synthase families

Publisher: Oxford University Press (OUP)

Date: 04-2001

DOI: 10.1104/PP.125.4.2040

Abstract: The walls deposited by growing pollen tubes contain two types of β-glucan, the (1,3)-β-glucan callose and the (1,4)-β-glucan cellulose, as well as various α-linked pectic polysaccharides. Pollen tubes of Nicotiana alata Link et Otto, an ornamental tobacco, were therefore used to identify genes potentially encoding catalytic subunits of the callose synthase and cellulose synthase enzymes. Reverse transcriptase-polymerase chain reactions (RT-PCR) with pollen-tube RNA and primers designed to conserved regions of bacterial and plant cellulose synthase (CesA) genes lified a fragment that corresponded to an abundantly expressed cellulose-synthase-like gene named NaCslD1. A fragment from a true CesA gene (NaCesA1) was also lified, but corresponding cDNAs could not be identified in a pollen-tube library, consistent with the very low level of expression of the NaCesA1 gene. RT-PCR with pollen-tube RNA and primers designed to regions conserved between the fungalFKS genes [that encode (1,3)-β-glucan synthases] and their presumed plant homologs (the Gsl or glucan-synthase-like genes) lified a fragment that corresponded to an abundantly expressed gene named NaGsl1. A secondGsl gene detected by RT-PCR (NaGsl2) was expressed at low levels in immature floral organs. The structure of full-length cDNAs of NaCslD1, NaCesA1, and NaGsl1 are presented. Both NaCslD1and NaGsl1 are predominantly expressed in the male gametophyte (developing and mature pollen and growing pollen tubes), and we propose that they encode the catalytic subunits of two β-glucan synthases involved in pollen-tube wall synthesis. Different β-glucans deposited in one cell type may therefore be synthesized by enzymes from different gene families.

Understanding and controlling plant development

Publisher: Elsevier BV

Date: 09-1995

DOI: 10.1016/S0167-7799(00)88978-7

Evolutionary Dynamics of Dual-Specificity Self-Incompatibility Alleles

Publisher: Oxford University Press (OUP)

Date: 03-2000

DOI: 10.1105/TPC.12.3.310

Metabolic responses to salt stress of barley (Hordeum vulgare L.) cultivars, Sahara and Clipper, which differ in salinity tolerance

Publisher: Oxford University Press (OUP)

Date: 10-08-2009

DOI: 10.1093/JXB/ERP243

In Vitro Grown Pollen Tubes of Nicotiana alata Actively Synthesise a Fucosylated Xyloglucan

Publisher: Public Library of Science (PLoS)

Date: 08-10-2013

DOI: 10.1371/JOURNAL.PONE.0077140

Self-compatibility in aLycopersicon peruvianum variant (LA2157) is associated with a lack of style S-RNase activity

Publisher: Springer Science and Business Media LLC

Date: 08-1994

DOI: 10.1007/BF01253997

Genetic variation in Banksia saxicola (Proteaceae), a rare Australian plant with a markedly disjunct distribution

Publisher: Springer Science and Business Media LLC

Date: 10-05-2001

DOI: 10.1007/S006060170059

Regulation of LAT52 promoter activity during pollen tube growth through the pistil of Nicotiana alata

Publisher: Springer Science and Business Media LLC

Date: 28-06-2000

DOI: 10.1007/S004970000022

Supplementary material to &quot;Development and evaluation of pollen source methodologies for the Victorian Grass Pollen Emissions Module VGPEM1.0&quot;

Publisher: Copernicus GmbH

Date: 15-02-2019

DOI: 10.5194/GMD-2019-43-SUPPLEMENT

An investigation of phyllode variation in Acacia verniciflua and A. leprosa (Mimosaceae), and implications for taxonomy

Publisher: CSIRO Publishing

Date: 2005

DOI: 10.1071/SB04052

Abstract: Acacia verniciflua A.Cunn. and A. leprosa Sieber ex DC. are believed to be closely related, although strict interpretation of the current sectional classification of subgenus Phyllodineae places them in separate sections based on main nerve number. Six populations, comprised of the common and the southern variants of A. verniciflua and the large phyllode variant of A. leprosa, were s led to test the value of nerve number as a taxonomic character and the current delimitation of these geographically variable species. Morphometrics, microscopy and the AFLP technique were used to compare and contrast populations. Phyllode nerve development was investigated and the abaxial nerve was found to be homologous with the mid-rib of a simple leaf. Three taxa were differentiated, two that are consistently two-nerved and one taxon that is variably one-nerved, two-nerved or both within a single plant. The first two-nerved taxon, characterised by smaller phyllodes, matches the type specimen of A. verniciflua. The second two-nerved taxon, characterised by large phyllodes, is apparently endemic to Mt William. The third taxon, with variable main nerve number, also has large phyllodes, and combines large phyllode variant A. leprosa (Wilhelmina Falls) and southern variant A. verniciflua (Kinglake) in iduals. The number of main nerves per face in phyllodes is not a useful taxonomic character for sectional classification of Acacia. Although it has clearly proved functional in some instances, the character appears too variable to reliably define natural monophyletic groups. Anatomical features such as cell number of resinous glands and staining patterns proved to be informative.

The 1.55 Å resolution structure of Nicotiana alata SF11-RNase associated with gametophytic self-incompatibility

Publisher: Elsevier BV

Date: 11-2001

DOI: 10.1006/JMBI.2001.5127

A molecular perspective on pollination in flowering plants

Publisher: Elsevier BV

Date: 04-1996

DOI: 10.1016/S0092-8674(00)81090-9

Abstract: Copper radical alcohol oxidases (CRO-AlcOx), which have been recently discovered among fungal phytopathogens, are attractive for the production of fragrant fatty aldehydes. With the initial objective to investigate the secretion of CRO-AlcOx by natural fungal strains, we undertook time course analyses of the secretomes of three Colletotrichum species (C. graminicola, C. tabacum, and C. destructivum) using proteomics. The addition of a copper-manganese-ethanol mixture in the absence of any plant-biomass mimicking compounds to Colletotrichum cultures unexpectedly induced the secretion of up to 400 proteins, 29 to 52% of which were carbohydrate-active enzymes (CAZymes), including a wide ersity of copper-containing oxidoreductases from the auxiliary activities (AA) class (AA1, AA3, AA5, AA7, AA9, AA11, AA12, AA13, and AA16). Under these specific conditions, while a CRO-glyoxal oxidase from the AA5_1 subfamily was among the most abundantly secreted proteins, the targeted AA5_2 CRO-AlcOx were secreted at lower levels, suggesting heterologous expression as a more promising strategy for CRO-AlcOx production and utilization. C. tabacum and C. destructivum CRO-AlcOx were thus expressed in Pichia pastoris, and their preference toward both aromatic and aliphatic primary alcohols was assessed. The CRO-AlcOx from C. destructivum was further investigated in applied settings, revealing a full conversion of C

Do levels of airborne grass pollen influence asthma hospital admissions?

Publisher: Wiley

Date: 17-09-2007

DOI: 10.1111/J.1365-2222.2007.02818.X

Abstract: The effects of environmental factors and ambient concentrations of grass pollen on allergic asthma are yet to be established. We sought to estimate the independent effects of grass pollen concentrations in the air over Melbourne on asthma hospital admissions for the 1992-1993 pollen season. Daily grass pollen concentrations were monitored over a 24-h period at three stations in Melbourne. The outcome variable was defined as all-age asthma hospital admissions with ICD9-493 codes. The ambient air pollutants were average daily measures of ozone, nitrogen dioxide and sulphur dioxide, and the airborne particle index representing fine particulate pollution. Semi-parametric Poisson regression models were used to estimate these effects, adjusted for air temperature, humidity, wind speed, rainfall, day-of-the-week effects and seasonal variation. Grass pollen was a strong independent non-linear predictor of asthma hospital admissions in a multi-pollutant model (P=0.01). Our data suggest that grass pollen had an increasing effect on asthma hospital admissions up to a threshold of 30 grains/m3, and that the effect remains stable thereafter. Our findings suggest that grass pollen levels influence asthma hospital admissions. High grass pollen days, currently defined as more than 50 grains/m3, are days when most sensitive in iduals will experience allergic symptoms. However, some asthmatic patients may be at a significant risk even when airborne grass pollen levels are below this level. Patients with pollen allergies and asthma would be advised to take additional preventive medication at lower ambient concentrations.

Are designer plant cell walls a realistic aspiration or will the plasticity of the plant's metabolism win out?

Publisher: Elsevier BV

Date: 04-2013

DOI: 10.1016/J.COPBIO.2013.11.012

Abstract: Plants have been redesigned by humans since the advent of modern agriculture some 10000 years ago, to provide ever increasing benefits to society. The phenomenal success of the green revolution in converting biomass from vegetative tissues into grain yield has sustained a growing population. At the dawn of the 21st century the need to further optimise plant biomass (largely plant walls) for a sustainable future is increasingly evident as our supply of fossil fuels is finite and the quality of our crop-based foods (functional foods also determined by the composition of walls) are critical to maintaining a healthy lifestyle. Our capacity to engineer 'designer walls' suited to particular purposes is challenging plant breeders and biotechnologists in unprecedented ways. In this review we provide an overview of the critical steps in the assembly and remodelling of walls, the success (or otherwise) of such approaches and highlight another complex network, the cell surface, as a cell wall integrity (CWI) sensor that exerts control over wall composition and will need to be considered in any future modification of walls for agro-industrial purposes.

Pollen-expressed S-RNases are not involved in self-incompatibility in Lycopersicon peruvianum

Publisher: Springer Science and Business Media LLC

Date: 29-06-1999

DOI: 10.1007/S004970050175

Crystallization and preliminary X-ray crystallographic analysis ofS-allelic glycoproteinS_F11-RNase fromNicotiana alata

Publisher: International Union of Crystallography (IUCr)

Date: 2001

DOI: 10.1107/S0907444900014050

Abstract: Nicotiana alata S(F11)-RNase is an S-glycoprotein associated with gametophytic self-incompatibility. Crystals of S(F11)-RNase have been grown at room temperature using polyethylene glycol as a precipitant. A crystal diffracted to better than 1.4 A resolution at 100 K at the SPring-8 synchrotron-radiation source, indicating that it is very suitable for high-resolution structure analysis. The crystal belongs to the space group P2(1), with unit-cell parameters a = 65.86 (11), b = 44.73 (5), c = 64.36 (7) A, beta = 90.27 (9) degrees. The asymmetric unit contains two monomers, giving a crystal volume per protein mass (V(M)) of 2.05 A(3) Da(-1) and a solvent content of 39.6% by volume. A full set of X-ray diffraction data was collected to 1.55 A resolution with a completeness of 97.4%. A heavy-atom derivative has been successfully prepared with ethylmercury thiosalicylate (EMTS) and structure analysis is in progress.

An investigation of genetic variation in Banksia integrifolia (Proteaceae) by the use of the AFLP technique

Publisher: CSIRO Publishing

Date: 2002

DOI: 10.1071/SB01013

Abstract: The Banksia integrifolia L.f. species complex has undergone several taxonomic treatments over the past 20 years. In order to gain further insight into phenetic relationships between the taxa of this species, the distribution of genetic variation over the geographic range of B. integrifolia was investigated by the lified fragment length polymorphism (AFLP) technique. Ordination and classification analyses resulted in clusters of in iduals that closely conformed to the different taxa of this species. Further ordination and classification analyses of in iduals of just B. integrifolia subsp. integrifolia indicate that there are also geographical patterns within the subspecies, with those in iduals from the north of the species’ range clustering away from those in the south of the range. A Mantel-test between morphological data collected in a previous study and molecular data collected in this study indicated a highly significant correlation between morphological and genetic variation. This study thus supports the current taxonomic classification of the B. integrifolia species complex.

Access relative to need for community conservation funding in Australia

Publisher: Informa UK Limited

Date: 21-03-2019

DOI: 10.1080/13527258.2019.1590446

Aberrant cell expansion in the elongation mutants of barley

Publisher: Oxford University Press (OUP)

Date: 30-01-2009

DOI: 10.1093/PCP/PCP015

Abstract: The elongation (elo) mutants of barley (Hordeum vulgare cv 'Himalaya') are a class of dwarf plants with defects affecting cell expansion. The phenotypes of mutants in three of the elo loci (elo1, elo2 and elo3) are recessive to the wild-type allele, and the mutations at elo-4 and elo-5 are semi-dominant. Allelism tests showed that elo1, elo2 and elo3 were at separate loci, and mapping data indicated that elo-5 was possibly allelic to either elo1 or elo2. A phenotype common to all elo mutants was the presence of short, radially swollen cells on the leaf epidermis, indicating a defect in longitudinal cell expansion. In three of the mutants, elo1, elo3 and elo5, this was accompanied by a twisting growth habit. Two of the mutations, elo2 and elo-5, affected cell ision, with aberrant periclinal cell ision resulting in the formation of increased cell layers in the leaf epidermis of elo2 and elo-5 homozygotes and in the aleurone layer of elo2 grains. Misplaced anticlinal isions also occurred in the elo-5 leaf epidermis. Leaf cell walls of all elo lines contained less cellulose than the wild- type, and the cortical microtubules in elongating root epidermal cells in some elo lines were more randomly oriented than in the wild-type, consistent with the presence of radially swollen cells. We discuss possible functions for the Elo genes in primary cell wall synthesis.

A relic S-RNase is expressed in the styles of self-compatible Nicotiana sylvestris.

Publisher: Wiley

Date: 12-1998

DOI: 10.1046/J.1365-313X.1998.00331.X

Abstract: We surveyed ribonuclease activity in the styles of Nicotiana spp. and found little or no activity in self-compatible species and in a self-compatible accession of a self-incompatible species. All self-incompatible species had high levels of ribonuclease activity in their style. Interestingly, one self-compatible species, N. sylvestris, had a level of stylar ribonuclease activity comparable to that of some self-incompatible Nicotiana species. A ribonuclease with biochemical properties similar to those of the self-incompatibility (S-)RNases of N. alata was purified from N. sylvestris styles. The N-terminal sequence of this protein was used to confirm the identity of a cDNA corresponding to the stylar RNase. The amino acid sequence deduced from the cDNA was related to those of the S-RNases and included the five conserved regions characteristic of these proteins. It appears that the N. sylvestris RNase may have evolved from the S-RNases and is an ex le of a 'relic S-RNase'. A number of features distinguish the N. sylvestris RNase from the S-RNases, and the role these may have played in the presumed loss of the self-incompatibility response during the evolution of this species are discussed.

Self-incompatibility in flowering plants.

Publisher: Elsevier BV

Date: 10-1995

DOI: 10.1016/0959-437X(95)80033-6

Abstract: Fertilization in flowering plants begins with a pollen grain bearing the male gametes landing on the female stigma. Several mechanisms enable the stigma to discriminate between the different types of pollen that it may receive, of which the best studied is self-incompatibility. The molecules that regulate self-incompatibility are well characterized in two plant families, the Solanaceae and Brassicaceae. This list has recently been extended to include candidates for self-incompatibility molecules from the Rosaceae, Papaveraceae and Poaceae. The information provided by the sequences of these molecules gives insight into the mechanisms and evolution of self-incompatibility in the different families of flowering plants.

Expression of 10 S-class SLF-like genes in Nicotiana alata pollen and its implications for understanding the pollen factor of the S locus

Publisher: Oxford University Press (OUP)

Date: 12-2007

DOI: 10.1534/GENETICS.107.076885

Abstract: The S locus of Nicotiana alata encodes a polymorphic series of ribonucleases (S-RNases) that determine the self-incompatibility (SI) phenotype of the style. The pollen product of the S locus (pollen S) in N. alata is unknown, but in species from the related genus Petunia and in self-incompatible members of the Plantaginaceae and Rosaceae, this function has been assigned to an F-box protein known as SLF or SFB. Here we describe the identification of 10 genes (designated DD1–10) encoding SLF-related proteins that are expressed in N. alata pollen. Because our approach to cloning the DD genes was based on sequences of SLFs from other species, we presume that one of the DD genes encodes the N. alata SLF ortholog. Seven of the DD genes were exclusively expressed in pollen and a low level of sequence variation was found in alleles of each DD gene. Mapping studies confirmed that all 10 DD genes were linked to the S locus and that at least three were located in the same chromosomal segment as pollen S. Finally, the different topologies of the phylogenetic trees produced using available SLF-related sequences and those produced using S-RNase sequences suggests that pollen S and the S-RNase have different evolutionary histories.

Development and evaluation of pollen source methodologies for the Victorian Grass Pollen Emissions Module VGPEM1.0

Publisher: Copernicus GmbH

Date: 15-02-2019

DOI: 10.5194/GMD-2019-43

Abstract: Abstract. We present the first representation of grass pollen in a 3D dispersion model anywhere in Australia, tested using observations from eight counting sites in Victoria. The region's population has high rates of allergic rhinitis and asthma, and this has been linked to the high incidence of grass pollen allergy. Despite this, grass pollen dispersion in the Australian atmosphere has not been studied previously, and its source strength is untested. We describe ten pollen emission source methodologies examining the strengths of different immediate and seasonal timing functions, and spatial distribution of the sources. The timing function assumes a smooth seasonal term, modulated by an hourly meteorological function. A simple Gaussian representation of the pollen season worked well (average r = 0.54), but lacks the spatial and temporal variation that the satellite-derived Enhanced Vegetation Index (EVI) data can provide. However poor results were obtained using the EVI gradient (average r = 0.35), which gives the timing when grass turns from maximum greenness to a drying and flowering period this is due to the greater spatial and temporal variability from this combined spatial and seasonal term. Better results were obtained using statistical methods that combine elements of the EVI dataset, a smooth seasonal term and instantaneous variation based on historical grass pollen observations (average r = 0.69). The seasonal magnitude is inferred from the maximum winter-time EVI, while the timing of the peak of the season was based on the day of the year when the EVI falls to 0.05 below its winter maximum. Measurements are vital to monitor changes in the pollen season, and the new pollen measurement sites in the Victorian network should be maintained.

Maximum-Likelihood Estimation of Rates of Recombination Within Mating-Type Regions

Publisher: Oxford University Press (OUP)

Date: 08-2004

DOI: 10.1534/GENETICS.103.021535

Abstract: Features common to many mating-type regions include recombination suppression over large genomic tracts and cosegregation of genes of various functions, not necessarily related to reproduction. Model systems for homomorphic self-incompatibility (SI) in flowering plants share these characteristics. We introduce a method for the exact computation of the joint probability of numbers of neutral mutations segregating at the determinant of mating type and at a linked marker locus. The underlying Markov model incorporates strong balancing selection into a two-locus coalescent. We apply the method to obtain a maximum-likelihood estimate of the rate of recombination between a marker locus, 48A, and S-RNase, the determinant of SI specificity in pistils of Nicotiana alata. Even though the s led haplotypes show complete allelic linkage disequilibrium and recombinants have never been detected, a highly significant deficiency of synonymous substitutions at 48A compared to S-RNase suggests a history of recombination. Our maximum-likelihood estimate indicates a rate of recombination of perhaps 3 orders of magnitude greater than the rate of synonymous mutation. This approach may facilitate the construction of genetic maps of regions tightly linked to targets of strong balancing selection.

Sex and self-denial

Publisher: Springer Science and Business Media LLC

Date: 05-2003

DOI: 10.1038/423229A

Trans-disciplinary research in synthesis of grass pollen aerobiology and its importance for respiratory health in Australasia

Publisher: Elsevier BV

Date: 11-2015

DOI: 10.1016/J.SCITOTENV.2015.04.001

The S-locus of Nicotiana alata: genomic organization and sequence analysis of two S-RNase alleles

Publisher: Springer Science and Business Media LLC

Date: 08-1995

DOI: 10.1007/BF00042070

Development and evaluation of pollen source methodologies for the Victorian Grass Pollen Emissions Module VGPEM1.0

Publisher: Copernicus GmbH

Date: 04-06-2019

DOI: 10.5194/GMD-12-2195-2019

Abstract: Abstract. We present the first representation of grass pollen in a 3-D dispersion model in Australia, tested using observations from eight counting sites in Victoria. The region's population has high rates of allergic rhinitis and asthma, and this has been linked to the high incidence of grass pollen allergy. Despite this, grass pollen dispersion in the Australian atmosphere has not been studied previously, and its source strength is untested. We describe 10 pollen emission source methodologies examining the strengths of different immediate and seasonal timing functions, and the spatial distribution of the sources. The timing function assumes a smooth seasonal term, modulated by an hourly meteorological function. A simple Gaussian representation of the pollen season worked well (average r=0.54), but lacked the spatial and temporal variation that the satellite-derived enhanced vegetation index (EVI) can provide. However, poor results were obtained using the EVI gradient (average r=0.35), which provides the timing when grass turns from maximum greenness to a drying and flowering period this is due to noise in the spatial and temporal variability from this combined spatial and seasonal term. Better results were obtained using statistical methods that combine elements of the EVI dataset, a smooth seasonal term and instantaneous variation based on historical grass pollen observations (average r=0.69). The seasonal magnitude is inferred from the maximum winter-time EVI, whereas the timing of the season peak is based on the day of the year when the EVI falls to 0.05 below its winter maximum. Measurements are vital to monitor changes in the pollen season, and the new pollen measurement sites in the Victorian network should be maintained.

Karyotypic variation in Nicotiana section Suaveolentes

Publisher: Springer Science and Business Media LLC

Date: 13-07-2011

DOI: 10.1007/S10722-011-9724-3

INSTITUTO DO MEIO AMBIENTE DE SANTA CATARINA

Location: Brazil

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Université Grenoble Alpes-INRAE

Location: France

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Australian National University

Location: Australia

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University Of Melbourne

Location: Australia

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Discovery Projects - Grant ID: DP0557470

Start Date: 2005

End Date: 06-2008

Amount: $260,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE0668549

Start Date: 12-2006

End Date: 12-2007

Amount: $280,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP0343004

Start Date: 2003

End Date: 12-2007

Amount: $60,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP110100410

Start Date: 05-2011

End Date: 06-2014

Amount: $330,000.00

Funder: Australian Research Council