Polycomb-group genes are master regulators of development in plants and animals. They provide cells with a memory of their developmental identity, and in plants also of past environments to which they have been exposed. These memories consist of modifications in the histone proteins that package DNA, resulting in heritable changes in gene activity. Recent structural studies show that Polycomb proteins act together in large complexes which represent sophisticated molecular machines, able not only to write histone marks, but also to read and interpret them. I will describe the work of my group and others in showing how Polycomb proteins regulate flowering in Arabidopsis and then more recent work using genetic screens and proteomic approaches to identify novel components of the Polycomb machinery. Specifically, I will describe how plants have recycled transposases, generally thought to be parasitic elements, as novel regulators of their Polycomb and other epigenetic machinery. I propose that this may be the result of an evolutionary arms race between transposons and their hosts, much as plant viruses have evolved proteins to antagonise the RNAi machinery of their hosts.
题目：Evolution of a water proof skin and the multicellular embryo in land plants
Land plants are thought to have evolved from aquatic green algae. The move on to land required the development of a waterproof covering, the cuticle, to conserve water and also the development of a multicellular embryo. We identified a gene called Zhoupi which acts in the seed in Arabidopsis to promote cuticle development in the embryo and also to promote the breakdown of the surrounding endosperm, to allow the embryo to grow. In the first part of my talk I will describe work from my group and collorators identifying the targets and pathways controlled by Zhoupi during seed development in Arabidopsis. Strikingly, Zhoupi is found in all land plants, including basal lineages that lack seed. In the second part of the talk I will describe our recent unpublished work to identify the function of Zhoupi in early land plants. We are using the liverwort Marchantia polymorpha as a model system and we have applied the technique of CRISPR mediated genome editing to inactivate the Marchantia orthologues of the Zhoupi gene.
JustinGoodrich博士自2007年至今受聘英国爱丁堡大学生物学院发育生物学专业Senior Lecturer。早先为英国爱丁堡大学Royal Society University Research Fellow及Lecturer。曾在John Innes Centre, Norwich (UK) 和California Institute of Technology (USA) G. Coupland教授和E. Meyerowitz教授实验室做博士后工作。JustinGoodrich博士还曾受聘于英国Overseas Development Administration (ODA)和International Board for Plant Genetic Resources (IBPGR, FAO, Rome, Italy) 作为植物育种专家在叙利亚、马拉维和肯尼亚进行援助工作。Goodrich本科和硕士先后就读于英国牛津大学和英国剑桥大学，博士学位完成于University of East Anglia和John Innes Centre的E. S. Coen实验室，其博士论文荣获1993年Irene Manton prize for best thesis in Botany from Royal Linnean Society of London.
Fourquin, C., Beauzamy, L., Chamot, S., Creff, A.,Goodrich, J.,Boudaoud, A. and Ingram, G. (2016) 'Mechanical stress mediated by both endosperm softening and embryo growth underlies endosperm elimination in Arabidopsis seeds',Development143: 3300-5.
Zhang, Y., Li, X.,Goodrich, J., Wu, C., Wei, H., Yang, S. and Feng, X. (2016) 'Reduced function of the RNA-binding protein FPA rescues a T-DNA insertion mutant in the Arabidopsis ZHOUPI gene by promoting transcriptional read-through',Plant Mol Biol91: 549-61.
Liang, S*, Hartwig, B*, Perera, P, Mora-García, S, de Leau, E, Thornton, H, Lima de Alves, F, Rapsilber, J, Yang, S, Geo Velikkakam, J, Schneeberger, Finnegan, EJ, Turck, F♯,Goodrich, J♯(2015). Kicking against the PRCs – A domesticated transposase antagonises silencing mediated by Polycomb group proteins and is an accessory component of Polycomb Repressive Complex 2 in Arabidopsis.PLoS Genetics, 11 e1005660*equal contribution♯joint senior authors
*Ikeuchi, M, Iwase*, A, Rymen, B, Harashima, H, Shibata, M, Ohnuma, O, Breuer, C, Morao, A, de Lucas, M, de Veylder, L,Goodrich, J, Brady, S, Roudier, F and K Sugimoto (2015). PRC2 represses dedifferentiation of mature somatic cells in Arabidopsis.Nature Plants1, 1-7 .*equal contribution
Hautegem, T, Waters, A,Goodrich, Jand M. Nowack (2015) Only in Dying, Life: Programmed Cell Death in Plant Development. Trends in Plant Science,20: 102-13
Muller-Xing,R., Clarenz,O., Pokorny,L.,Goodrich,J♯., and Schubert,D♯. (2014). Polycomb-Group Proteins and FLOWERING LOCUS T Maintain Commitment to Flowering in Arabidopsis thaliana.Plant Cell26, 2457-2471. ♯Joint senior authors.
Lee, E., Lucas,J.R.,Goodrich,J., and Sack,F.D. (2014). Arabidopsis guard cell integrity involves the epigenetic stabilization of the FLP and FAMA transcription factor genes.Plant J.78, 566-577. D.S., 16-30.
Xing,Q., Creff,A., Waters,A., Tanaka,H.,Goodrich,J., and Ingram,G.C. (2013).ZHOUPIcontrols embryonic cuticle formation via a signalling pathway involving the subtilisin proteaseABNORMAL LEAF-SHAPE1and the receptor kinasesGASSHO1andGASSHO2.Development140, 770-779.
Lopez-Vernaza, M.,Yang,S., Muller,R., Thorpe,F., de,L.E., andGoodrich,J.(2012). Antagonistic roles ofSEPALLATA3,FTandFLCgenes as targets of the Polycomb group geneCURLY LEAF.PLoS. One.7,e30715.
Liu, X., Kim,Y.J., Muller,R., Yumul,R.E., Liu,C., Pan,Y., Cao,X.,Goodrich,J., and Chen,X. (2011).AGAMOUSterminates floral stem cell maintenance in Arabidopsis by directly repressingWUSCHELthrough recruitment of Polycomb Group proteins.Plant Cell23, 3654-3670
Farrona, S., Thorpe, F.L., Engelhorn, J., Adrian, J., Dong, X., Sarid-Krebs, L.,Goodrich, J., and F. Turck (2011). Tissue specific expression ofFLOWERING LOCUS TinArabidopsisis maintained independently of PcG repression. Plant Cell23: 3204-14
Bouyer, D., Roudier, F., Heese, M., Andersen, E. D., Gey, D., Nowack, M. K.,Goodrich, J., Renou, J. P., Grini, P. E., Colot, V. and A. Schnittger (2011) 'Polycomb repressive complex 2 controls the embryo-to-seedling phase transition',PLoS Genet7(3): e1002014
Bond, D. M., Buzas, D. M.,Goodrich, J., Helliwell, C. A., Tamada, Y., Yun, J. Y., Amasino, R. M. and Dennis, E. S. (2011) 'Polycomb proteins regulate the quantitative induction ofVERNALIZATION INSENSITIVE3 in response to low temperatures',Plant J65: 382-91.
