Welcome to the Golz Group
We are based in the School of BioSciences at The University of Melbourne. Our main focus is to understand how complex patterns of gene expression are generated and maintained during cell-type specification and differentiation in multicellular organisms. This problem is being addressed in the model plant Arabidopsis through the analysis of transcriptional regulators that control cell differentiation in embryos, leaves and the outer layer of the seed coat. We are also interested in understanding how these regulators elicit developmental responses in response to environmental stimuli, such as heat and salt stress.
More recently the group has begun to consider how knowledge of developmental regulation in Arabidopsis can be applied to reducing the time and cost associated with generating transgenic crop plants. The aim here is to help the agricultural industry more quickly assess gene function by circumventing the bottleneck associated with the use of tissue culture for plant transformation.
The group uses a range of platforms and techniques in their research; including RNA-seq, molecular analyses, and microscopy to address their questions.
We have shown that the Gro/TUP1-like co-repressors LEUNIG (LUG) and LEUNIG_HOMOLOG (LUH) control diverse processes in the plant including apical-basal and auxin patterning during early embryogenesis, cell fate acquisition in developing leaves, and pectin modification in the developing seed coat (Stahle et al., 2009; Walker et al., 2011; Lee et al., 2014). As LUG/LUH lack a DNA-binding domain, they must interact with DNA binding co-factors if they are to be recruited to the regulatory sequences of target genes. This may occur through direct interactions with transcription factors or indirectly via the adaptor proteins SEUSS (SEU) or SEU-LIKE proteins (SLKs). As a result of these interactions, LUG/LUH are part of a large regulatory complex.
Current research projects
- Using RNA-seq and chromatin immunoprecipitation to identify the network of genes controlled by the LUG/LUH regulatory complex during embryonic and post-embryonic development
- Using protein interaction assays to define the interactome of LUG/LUH and associated co-regulators SEU/SLKs.
- Attempting to produce canola varieties that can be transformed by floral dipping, a procedure used extensively in the model plant Arabidopsis.
PhD opportunities in the Golz lab
The group is offering two PhD projects through the Melbourne-Potsdam PhD Program – you can see the full listing of projects here. The program, which is a joint initiative between the University of Melbourne (UoM) – Australia, the Max Planck Institute of Molecular Plant Physiology (MPI-MP) and the University of Potsdam (UP) – Germany, creates an international research training opportunity for PhD students. Time is spent in labs in both Australia and Germany, and on completion of the program result in a joint PhD from the University of Melbourne and the University of Potsdam.
Applications are due 12th Feb 2018; for more information click here.
MSc opportunities in the Golz lab
Potential MSc projects in the Golz lab are listed below. More projects may be added over the coming weeks. Each project is carefully designed so that you gain experience in microscopy, molecular techniques as well as plant genetics. You will be supervised by the lab head and work closely with PhD students in the group. If you would like more information about these projects please email John Golz. It is also a requirement for the MSc application process that you meet with project supervisors before you list their projects on the MSc application form.
For more information about the Master of Science (BioSciences) program, click here.
Project #1: Genetic approaches to understanding seed mass control
To enhance seed yield crop breeding programs typically seek to increase seed mass. This is achieved by modulating one or more of the three major components of the seed – the embryo, endosperm and seed coat. In flowering plants, the seed is derived from the ovule following a double fertilisation event in which one sperm cell fuses with the egg cell to form the embryo and a second sperm cell fuses with the diploid central cell to form the triploid endosperm. The seed coat is of maternal origin and is derived from the integument layers surrounding the ovule. It is the extent of embryo, endosperm and seed coat growth that ultimately determines the final mass of the seed and thus identifying the genetic pathways that modulate this growth will enhance efforts to improve seed yield.
In our efforts to investigate gene regulation in the Arabidopsis seed coat, we recently generated a transgenic line that displayed a 1.8 to 2-fold increase in seed mass. While we do not yet understand the molecular basis for this increase, we think it is caused by a perturbation in the seed coat.
This project aims to:
- Use standard and scanning electron microscopy to investigate the cause of seed mass increase in the transgenic line
- Look at genetic interactions between this transgenic line and a variety of genes regulating seed mass in the seed coat, endosperm or embryo
- Use molecular approaches to monitor expression of genes regulating cell proliferation and cell elongation
Findings from this study will provide a better understanding of how seed mass is regulated at a genetic level, and may therefore help to improve crop improvement programs aimed at increasing seed yield.
Project #2: Metabolic control of post-translational modifications in embryo development
(with Mike Haydon)
Post-translational modifications of proteins, such as phosphorylation, acetylation or glycosylation, have important roles in modulating protein function in cells. O-linked N-acetylglucosomanine (O-GlcNAc) is emerging as a critical link between metabolic state and protein activity. Unlike the hundreds of kinases and phosphatases participating in protein phosphorylation, there are only two O-GlcNAc transferases (OGTs) encoded by SPINDLY (SPY) and SECRET AGENT (SEC) in Arabidopsis. A spy sec double mutant is embryo lethal, suggesting a critical role for protein O-GlcNAcylation in embryo development. A recent study reported a genome-wide survey of O-GlcNAcylated proteins and prominently identified components of the LEUNIG (LUG) repressor complex (Xu et al PNAS 2017). Similar to spy sec, double mutants between lug and closely related LEUNIG_HOMOLOG (LUH) are also embryo lethal. Since O-GlcNAcylation represents a regulatory input for metabolism on gene regulation, which is known to be important for embryo development, we wish to investigate the role of O-GlcNAcylation on the LUG repressor complex in developing embryos.
This project aims to:
- Use chemical and genetic tools to test effects of modified metabolism in embryo development
- Detect O-GlcNAcylation state of LUG and LUH by immunoblot
- Test functional role of OGT target sites in LUG repressor complex proteins by mutating O-GlcNAcylated residues
- Perform in situ hybridization for LUG complex gene targets in developing embryos of OGT mutants
- Generate mutant combinations between OGTs and lug and luh to test epistasis
Establishing that O-GlcNAcylation regulates LUG regulatory complex activity will provide a major breakthrough in understanding the molecular mechanism enabling metabolism to influence gene regulation during embryogenesis.
John completed his undergraduate degree at the University of East Anglia (UK) in 1992 and his PhD at the University of Melbourne (Australia) in 1998. He then took up an EMBO postdoctoral fellowship at the University of Edinburgh with Prof. Andrew Hudson. In 2003, John was awarded a ARC QEII fellowship and moved back to Australia to establish his own group at Monash University. Since 2006, he has been a group leader at the University of Melbourne, accepting a lectureship position in 2008.
Joanna completed her undergraduate degree in Biotechnology at the University of Wrocław, Poland. This was followed with a Master degree in Biotechnology from the same institution where she undertook a study of human metallothionein isoforms. As part of this MSc program, Joanna undertook two interneships at the MPI-Molecular Plant Physiology in Potsdam (Germany). Joanna joined the lab as a PhD in November 2016 and is studying the embryonic patterning pathways regulated by the LUG regulatory complex in the model plant Arabidopsis.
Qiwei Li, PhD candidate (Chinese Scholarship Council Scholarship) – joined the lab in 2017.
Qiwei completed her undergraduate degree at Agricultural University of Hebei followed by a Master degree in China Agricultural University, working on the function of Ethylene transcription factors in iron deficiency in Malus xiaojinensis. She joined the lab as a PhD in September 2017. Her project aims to investigate the function of SEU and LUG regulatory complex in auxin patterning in Liverwort Marchantia polymorpha.
Former Lab members:
Debra David – currently writing up
Mahmud Hassan – submitted March 2018
Oliver Bonnacorso – submitted Dec 2017
Nadeeka Jayawardana – completed in 2016 – Returned to a lecturing position at the University of Peradeniya (Sri Lanka)
Joanne Lee – completed in 2014 – Postdoc with Markus Schmidt, Umea University (Sweden)
Melissa Mail (nee Stahle) – completed in 2009 – Now working as a Commercial Development Officer, University of Sydney
Arca Zaw – completed in 2017 – Currently looking for work
David Yoannidis – completed in 2015 – Now working as a medical scientist in the Peter MacCallum Pathology Department
Paul DeFazio – completed in 2013 – Now working as a medical scientist in the Monash Health Cytogenetics pathology laboratory
Murray Walker – completed in 2009 – Now working as a senior programs officer at Scienceworks, Museum Victoria
Francis Tenazas – completed in 2015 – Now working for DTS Food Laboratories as a Lab Analyst
Libby Puah – completed in 2010 and is now working as a lab technician in Singapore
Janine Kuehlich – completed in 2008 – Now working as a Business Designer for ThinkPlace
Adi Suputra – completed in 2007, returned to Indonesia
- Golz J.F. (2005) Lessons from the vegetative shoot apex. In Intercellular communications in plants (Ed A. Fleming), Blackwell, Oxford. pp 147-177
- Lee, J.E. and Golz J.F. (2012). Diverse roles of Groucho/Tup1 co-repressors in plant growth and development. Plant Signaling and Behavior 7, 86-92
- Stahle, M.I., Bonaccorso, O. and Golz J.F. (2008) Signalling: The green light to leaf development. Intl J. Plant Develop. Biol. 2, 13-24
- Golz J.F. (2006) Signalling between the shoot apical meristem and developing lateral organs. Plant Mol. Biol. 60, 889-903
- Golz J.F. and Hudson A. (2002) Signalling in plant lateral organ development. Plant Cell 14, S277-S288
- Golz J.F., Clarke A.E. and Newbigin E. (2000) Mutational approaches to the study of self incompatibility: revisiting the pollen-part mutants. Ann. Bot. 85 (Sup A), 95-103
- Golz J.F. and Hudson A. (1999) YABBYs claw to the fore. Curr. Biology 9, R861-R863
- Golz J.F., Newbigin E. and Clarke A.E. (1995) Self-incompatibility in flowering plants. Curr. Opin. Genet. Develop. 5, 640-645
Primary Research Articles
- Flores-Sandoval, E., Eklund, M.D., Hong, S-F., Alvarez, J., Fisher, T., Lampugnani, E., Golz, J., Vázquez-Lobo, A., Dierschke, T., Lin, S-S. and Bowman, J. (In Press) Class C ARFs evolved before the origin of land plants and antagonize differentiation and developmental transitions in Marchantia polymorpha. New Phytologist
- Amanda, D., Doblin, M.S., MacMillan, C., Galletti, R, Golz, J.F., Bacic, A, Ingram, G.C., and Johnson, K.L. (2017) Arabidopsis DEFECTIVE KERNEL1 regulates cell wall composition and axial growth in the inflorescence stem. Plant Direct DOI: 10.1002/pld3.27
- Geng, X. Horst, W.J., Golz, J.F., Lee, J.E., Ding, Z., and Yang, Z-B. (2017) LEUNIG_HOMOLOG mediates aluminum sensitivity through PECTIN METHYLESTERASE46-modulated cell-wall pectin methylesterification in Arabidopsis. Plant J. 90, 491-504
- Lim, B., Smirnoff, N., Cobbett, C. S. and Golz, J.F. (2016) Ascorbate-deficient vtc2 mutants in Arabidopsis do not exhibit decreased growth. Front. Plant Sci. (doi: 10.3389/fpls.2016.01025)
- Lampugnani, E.R, Ho, Y.Y., Moller, I.E., Koh, P-L., Golz, J.F., Bacic, A. and Newbigin, E. (2016) A glycosyl transferase from Nicotiana pollen mediates synthesis of a linear (1,5)-α-L-arabinan when expressed in Arabidopsis. Plant Physiol. 170, 1962-1974
- Good, R.T., Varghese, T., Golz, J.F., Russell, D.A., Edwards, O. and Robin.C (2016) OffTargetFinder: a webtool for species-specific RNAi design. Bioinformatics 32, 1232-1234
- Boter, M., Golz, J.F., Giménez-Ibañez, S., Franco-Zorrilla, J.M., Díez-Díaz, M. and Solano, R. (2015) FILAMENTOUS FLOWER is a direct target of JAZ3 and modulates responses to jasmonate. Plant Cell 27, 3160-3174
- Lee, J.E., Lampugnani, E.R., Bacic, A. and Golz J.F. (2014) SEUSS and SEUSS-LIKE 2 coordinate auxin distribution and KNOXI activity during embryogenesis. Plant J. 80, 122-135
- Bonaccorso, O., Lee, J.E., Puah, L., Scutt, C.P. and Golz J.F. (2012) FILAMENTOUS FLOWER controls lateral organ development by acting as both an activator and a repressor. BMC Plant Biology 12, 176-195
- Walker, M., Tehseen, M., Doblin, M.S., Pettolino, A., Wilson, S.M., Bacic, A. and Golz J.F. (2011). The transcriptional regulator LEUNIG_HOMOLOG regulates mucilage release from the Arabidopsis testa. Plant Physiol. 156, 46–60
- Stahle, M.I., Kuehlich, J., Staron, L., von Arnim, A. and Golz J.F. (2009) YABBYs and the transcriptional co-repressors LEUNIG and LEUNIG HOMOLOG maintain leaf polarity and meristem activity in Arabidopsis. Plant Cell 21, 3105-3118
- Golz J.F., Roccaro, M., Kuzoff, R. and Hudson, A. (2004) GRAMINIFOLIA promotes growth and polarity of Antirrhinum. Development 131, 3661-3670
- Navarro, C., Efremova, N., Golz J.F., Rubiera, R., Kuckenburg, M., Castillo, R., Tietz, O., Saedler, H. and Schwarz-Sommer, Z. (2004) Molecular and genetic interactions between STYLOSA and GRAMINIFOLIA in the control of Antirrhinum vegetative and floral development. Development 131, 3649-3659
- Schwarz-Sommer Z., Silva E.D., Berndtgen R., Lonnig W.E., Muller A., Nindl I., Stuber K., Wunder J., Saedler H., Gubitz T., Borking A., Golz J.F., Ritter E. and Hudson A. (2003) A linkage map of an F-2 hybrid population of Antirrhinum majus and A. molle. Genetics 163, 699-710
- Golz J.F., Keck E. and Hudson A. (2002) Spontaneous mutations in knox genes give rise to a novel floral structure in Antirrhinum. Curr. Biology 12, 515-522
- Golz J.F., Young H., Su V., Kusaba M. and Newbigin E. (2001) Genetic analysis of Nicotiana pollen-part mutants is consistent with the presence of an S-ribonuclease inhibitor at the S locus. Proc. Natl. Acad. Sci. USA 98, 15372-15376
- Tsiantis M., Schneeberger R., Golz J.F., Freeling M. and Langdale J.A. (1999) The maize rough sheath2 gene and leaf development programs in monocot and dicot plants. Science 284, 154-156
- Golz J.F., Su V., Clarke A.E. and Newbigin E. (1999) A molecular description of mutations affecting the pollen component of the Nicotiana alata S locus. Genetics 152, 1123-1135
- Golz J.F., Clarke A.E., Newbigin E. and Anderson M.A. (1998) A relic S-RNase is expressed in the styles of self-compatible Nicotiana sylvestris. Plant J. 16, 591-599
- Vissers A., Dodds P.N., Golz J.F. and Clarke A.E. (1995) Cloning and nucleotide sequence of the S7-RNase from Nicotiana alata Link and Otto. Plant Physiol. 108, 427-428