ORCID Profile
0000-0003-0455-9699
Current Organisations
Monash University
,
Australian National University
,
University of Adelaide
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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)
Genetics | Gene Expression | Botany Not Elsewhere Classified | Genetic Development (Incl. Sex Determination) | Developmental Genetics (incl. Sex Determination) | Evolution of Developmental Systems | Biochemistry and Cell Biology | Cellular Interactions (Incl. Adhesion, Matrix, Cell Wall) | Optical And Photonic Systems | Cell Development (Incl. Cell Division And Apoptosis) |
ANZSRC Socio-Economic Objective (SEO)
Biological sciences | Telecommunications | Urogenital system and disorders | Expanding Knowledge in the Biological Sciences | Organs, diseases and abnormal conditions not elsewhere classified
Related Links
Publications
The trihelix family of transcription factors - light, stress and development
Publisher: Elsevier BV
Date: 03-2012
DOI: 10.1016/J.TPLANTS.2011.12.002
Abstract: GT factors are the founding members of the trihelix transcription factor family. They bind GT elements in light regulated genes, and their nature was uncovered in a burst of activity in the 1990s. Study of the trihelix family then slowed. However, interest is now re-awakening. Genomic studies have revealed 30 members of this family in Arabidopsis and 31 in rice, falling into five clades. Newly discovered functions involve responses to salt and pathogen stresses, the development of perianth organs, trichomes, stomata and the seed abscission layer, and the regulation of late embryogenesis. Thus the time is ripe for a review of the genomic and functional information now emerging for this neglected family.
Helical growth in plant organs: mechanisms and significance
Publisher: The Company of Biologists
Date: 15-09-2016
DOI: 10.1242/DEV.134064
Abstract: Many plants show some form of helical growth, such as the circular searching movements of growing stems and other organs (circumnutation), tendril coiling, leaf and bud reversal (resupination), petal arrangement (contortion) and leaf blade twisting. Recent genetic findings have revealed that such helical growth may be associated with helical arrays of cortical microtubules and of overlying cellulose microfibrils. An alternative mechanism of coiling that is based on differential contraction within a bilayer has also recently been identified and underlies at least some of these growth patterns. Here, I provide an overview of the genes and cellular processes that underlie helical patterning. I also discuss the ersity of helical growth patterns in plants, highlighting their potential adaptive significance and comparing them with helical growth patterns in animals.
Functional domains of SPATULA, a bHLH transcription factor involved in carpel and fruit development in Arabidopsis
Publisher: Wiley
Date: 07-2008
Genes directing flower development in Arabidopsis.
Publisher: Oxford University Press (OUP)
Date: 1989
DOI: 10.1105/TPC.1.1.37
SPATULA and ALCATRAZ, are partially redundant, functionally diverging bHLH genes required for Arabidopsis gynoecium and fruit development
Publisher: Wiley
Date: 19-09-2011
Regulation of tissue-specific expression of SPATULA, a bHLH gene involved in carpel development, seedling germination, and lateral organ growth in Arabidopsis
Publisher: Oxford University Press (OUP)
Date: 22-02-2010
DOI: 10.1093/JXB/ERQ015
Functional domains of the PETAL LOSS protein, a trihelix transcription factor that represses regional growth in Arabidopsis thaliana
Publisher: Wiley
Date: 09-07-2014
DOI: 10.1111/TPJ.12574
Abstract: PETAL LOSS (PTL) is a trihelix transcription factor that represses growth, especially between sepal primordia. As one of 30 trihelix proteins in Arabidopsis, it falls in the GT2 clade with duplicated trihelix DNA-binding domains and a long α-helical central domain. PTL orthologs occur in all angiosperm genomes examined except grasses, and sequence comparisons reveal that there are two further short conserved domains at each end. GT2 itself carries two nuclear localization sequences, but PTL has an additional nuclear localization sequence (NLS). We show that PTL can act as a transcriptional activator in yeast and in planta, with the latter tested by two different functional assays. Specific deletions revealed that the activation region is C-terminal. Site-directed mutagenesis of the DNA-binding domains has shown that a conserved tryptophan and two downstream acidic amino acids in the second trihelix, predicted to promote folding, are each required for PTL function. Also, three basic residues in the third helix, near the DNA interaction sites, support its function. PTL was found to dimerize in yeast. This was confirmed and extended by jointly expressing differentially tagged forms of PTL in a transient expression system in Nicotiana benthamiana leaves. Cytoplasmic PTL (with mutant NLS sequences) was carried into the nucleus upon binding with nuclear-localized PTL, providing each partner carried intact central domains. As this 90-amino acid domain is conserved in most trihelix family members, it seems likely that they all function in dimeric form.
TheseirenaB Class Floral Homeotic Mutant of California Poppy (Eschscholzia californica) Reveals a Function of the Enigmatic PI Motif in the Formation of Specific Multimeric MADS Domain P
Publisher: Oxford University Press (OUP)
Date: 02-2013
Abstract: The products of B class floral homeotic genes specify petal and stamen identity, and loss of B function results in homeotic conversions of petals into sepals and stamens into carpels. Here, we describe the molecular characterization of seirena-1 (sei-1), a mutant from the basal eudicot California poppy (Eschscholzia californica) that shows homeotic changes characteristic of floral homeotic B class mutants. SEI has been previously described as EScaGLO, one of four B class–related MADS box genes in California poppy. The C terminus of SEI, including the highly conserved PI motif, is truncated in sei-1 proteins. Nevertheless, like the wild-type SEI protein, the sei-1 mutant protein is able to bind CArG-boxes and can form homodimers, heterodimers, and several higher order complexes with other MADS domain proteins. However, unlike the wild type, the mutant protein is not able to mediate higher order complexes consisting of specific B, C, and putative E class related proteins likely involved in specifying stamen identity. Within the PI motif, five highly conserved N-terminal amino acids are specifically required for this interaction. Several families lack this short conserved sequence, including the Brassicaceae, and we propose an evolutionary scenario to explain these functional differences.
Floral and Vegetative Morphogenesis in California Poppy (Eschscholzia californicaCham.)
Publisher: University of Chicago Press
Date: 07-2005
DOI: 10.1086/429866
Patterns of petal and stamen reduction in australian species of Lepidium l. (Brassicaceae)
Publisher: University of Chicago Press
Date: 1998
DOI: 10.1086/297522
PETAL LOSS, a trihelix transcription factor that represses growth in Arabidopsis thaliana, binds the energy-sensing SnRK1 kinase AKIN10
Publisher: Oxford University Press (OUP)
Date: 19-02-2015
DOI: 10.1093/JXB/ERV032
How flower development genes were identified using forward genetic screens in Arabidopsis thaliana
Publisher: Oxford University Press (OUP)
Date: 09-06-2023
Abstract: In the later part of the 1980s, the time was ripe for identifying genes controlling flower development. In that pregenomic era, the easiest way to do this was to induce random mutations in seeds by chemical mutagens (or irradiation) and to screen thousands of plants for those with phenotypes specifically defective in floral morphogenesis. Here, we discuss the results of premolecular screens for flower development mutants in Arabidopsis thaliana, carried out at Caltech and Monash University, emphasizing the usefulness of saturation mutagenesis, multiple alleles to identify full loss-of-function, conclusions based on multiple mutant analyses, and from screens for enhancer and suppressor modifiers of original mutant phenotypes. One outcome was a series of mutants that led to the ABC floral organ identity model (AP1, AP2, AP3, PI, and AG). In addition, genes controlling flower meristem identity (AP1, CAL, and LFY), floral meristem size (CLV1 and CLV3), development of in idual floral organ types (CRC, SPT, and PTL), and inflorescence meristem properties (TFL1, PIN1, and PID) were defined. These occurrences formed targets for cloning that eventually helped lead to an understanding of transcriptional control of the identity of floral organs and flower meristems, signaling within meristems, and the role of auxin in initiating floral organogenesis. These findings in Arabidopsis are now being applied to investigate how orthologous and paralogous genes act in other flowering plants, allowing us to wander in the fertile fields of evo-devo.
Evolution and genetic control of the floral ground plan
Publisher: Wiley
Date: 30-06-2018
DOI: 10.1111/NPH.15282
Abstract: Contents Summary 70 I. Introduction 70 II. What is the floral ground plan? 71 III. Diversity and evolution of the floral ground plan 72 IV. Genetic mechanisms 77 V. What's next? 82 Acknowledgements 83 References 83 SUMMARY: The floral ground plan is a map of where and when floral organ primordia arise. New results combining the defined phylogeny of flowering plants with extensive character mapping have predicted that the angiosperm ancestor had whorls rather than spirals of floral organs in large numbers, and was bisexual. More confidently, the monocot ancestor likely had three organs in each whorl, whereas the rosid and asterid ancestor (Pentapetalae) had five, with the perianth now ided into sepals and petals. Genetic mechanisms underlying the establishment of the floral ground plan are being deduced using model species, the rosid Arabidopsis, the asterid Antirrhinum, and in grasses such as rice. In this review, evolutionary and genetic conclusions are drawn together, especially considering how known genes may control in idual processes in the development and evolution of ground plans. These components include organ phyllotaxis, boundary formation, organ identity, merism (the number or organs per whorl), variation in the form of primordia, organ fusion, intercalary growth, floral symmetry, determinacy and, finally, cases where the distinction between flowers and inflorescences is blurred. It seems likely that new pathways of ground plan evolution, and new signalling mechanisms, will soon be uncovered by integrating morphological and genetic approaches.
PETAL LOSS is a boundary gene that inhibits growth between developing sepals in Arabidopsis thaliana
Publisher: Wiley
Date: 14-06-2012
Wrinkles on Sepals: Cuticular Ridges Form when Cuticle Production Outpaces Epidermal Cell Expansion
Publisher: Elsevier BV
Date: 04-2017
Transparent Testa Glabra2, a trichome and seed coat development gene of Arabidopsis, encodes a WRKY transcription factor
Publisher: Oxford University Press (OUP)
Date: 06-2002
DOI: 10.1105/TPC.001404
Abstract: Mutants of a new gene, TRANSPARENT TESTA GLABRA2 (TTG2), show disruptions to trichome development and to tannin and mucilage production in the seed coat. The gene was tagged by the endogenous transposon Tag1 and shown to encode a WRKY transcription factor. It is the first member of this large, plant-specific family known to control morphogenesis. The functions of all other WRKY genes revealed to date involve responses to pathogen attack, mechanical stress, and senescence. TTG2 is strongly expressed in trichomes throughout their development, in the endothelium of developing seeds (in which tannin is later generated) and subsequently in other layers of the seed coat, and in the atrichoblasts of developing roots. TTG2 acts downstream of the trichome initiation genes TTG1 and GLABROUS1, although trichome expression of TTG2 continues to occur if they are inactivated. Later, TTG2 shares functions with GLABRA2 in controlling trichome outgrowth. In the seed coat, TTG2 expression requires TTG1 function in the production of tannin. Finally, TTG2 also may be involved in specifying atrichoblasts in roots redundantly with other gene(s) but independently of TTG1 and GLABRA2.
Auxin controls petal initiation in Arabidopsis
Publisher: The Company of Biologists
Date: 2013
DOI: 10.1242/DEV.084582
Abstract: Floral organs are usually arranged in concentric whorls of sepals, petals, stamens and carpels. How founder cells of these organs are specified is unknown. In Arabidopsis, the PETAL LOSS (PTL) transcription factor functions in the sepal whorl, where it restricts the size of the inter-sepal zone. Genetic evidence suggests that PTL acts to support a petal initiation signal active in the adjacent whorl. Here we aimed to characterise the signal by identifying enhancers that disrupt initiation of the remaining petals in ptl mutants. One such enhancer encodes the auxin influx protein AUX1. We have established that auxin is a direct and mobile petal initiation signal by promoting its biosynthesis in the inter-sepal zone in ptl mutant plants and restoring nearby petal initiation. Consistent with this, loss of PTL function disrupts DR5 expression, an auxin-inducible indicator of petal-initiation sites. The signalling network was extended by demonstrating that: (1) loss of RABBIT EARS (RBE) function apparently disrupts the same auxin influx process as PTL (2) the action of AUX1 is supported by AXR4, its upstream partner in auxin influx (3) polar auxin transport, which is controlled by PINOID (PID) and PIN-FORMED1 (PIN1), functions downstream of PTL and (4) the action of pmd-1d, a dominant modifier of the ptl mutant phenotype, is dependent on auxin transport. Thus, loss of PTL function disrupts auxin dynamics, allowing the role of auxin in promoting petal initiation to be revealed.
PETAL LOSS, a trihelix transcription factor gene, regulates perianth architecture in the Arabidopsis flower
Publisher: The Company of Biologists
Date: 15-08-2004
DOI: 10.1242/DEV.01279
Abstract: Perianth development is specifically disrupted in mutants of the PETAL LOSS (PTL) gene, particularly petal initiation and orientation. We have cloned PTL and show that it encodes a plant-specific trihelix transcription factor, one of a family previously known only as regulators of light-controlled genes. PTL transcripts were detected in the early-developing flower, in four zones between the initiating sepals and in their developing margins. Strong misexpression of PTL in a range of tissues universally results in inhibition of growth, indicating that its normal role is to suppress growth between initiating sepals, ensuring that they remain separate. Consistent with this, sepals are sometimes fused in ptl single mutants, but much more frequently in double mutants with either of the organ boundary genes cup-shaped cotyledon1 or 2. Expression of PTL within the newly arising sepals is apparently prevented by the PINOID auxin-response gene. Surprisingly, PTL expression could not be detected in petals during the early stages of their development, so petal defects associated with PTLloss of function may be indirect, perhaps involving disruption to signalling processes caused by overgrowth in the region. PTL-driven reporter gene expression was also detected at later stages in the margins of expanding sepals, petals and stamens, and in the leaf margins thus, PTL may redundantly d en lateral outgrowth of these organs, helping define their final shape.
Interactions of CUP-SHAPED COTYLEDON and SPATULA Genes Control Carpel Margin Development in Arabidopsis thaliana
Publisher: Oxford University Press (OUP)
Date: 17-04-2012
DOI: 10.1093/PCP/PCS057
PETAL LOSS and ROXY1 Interact to Limit Growth Within and between Sepals But to Promote Petal Initiation in Arabidopsis thaliana
Publisher: Frontiers Media SA
Date: 08-02-2017
The Plant CellIntroduces Breakthrough Reports: A New Forum for Cutting-Edge Plant Research
Publisher: Oxford University Press (OUP)
Date: 20-10-2015
DOI: 10.1105/TPC.15.00862
Related Organisations
Related Funding Activities
Discovery Projects - Grant ID: DP0880214
Start Date: 04-2008
End Date: 04-2011
Amount: $259,000.00
Funder: Australian Research Council
View Funded ActivityLinkage Infrastructure, Equipment And Facilities - Grant ID: LE0561229
Start Date: 03-2005
End Date: 08-2007
Amount: $518,427.00
Funder: Australian Research Council
View Funded ActivityDiscovery Projects - Grant ID: DP130100177
Start Date: 06-2013
End Date: 09-2016
Amount: $430,000.00
Funder: Australian Research Council
View Funded ActivityDiscovery Projects - Grant ID: DP0879251
Start Date: 10-2008
End Date: 11-2008
Amount: $957,500.00
Funder: Australian Research Council
View Funded ActivityDiscovery Projects - Grant ID: DP0451208
Start Date: 2004
End Date: 12-2007
Amount: $300,000.00
Funder: Australian Research Council
View Funded Activity