Ancient mechanisms of expansion: exploring the evolution of plant physical biology
Lead Research Organisation:
University of Cambridge
Department Name: Sainsbury Laboratory
Abstract
Plant cell expansion is a fundamentally physical process: the force for expansion is provided by turgor pressure, and changes in material properties allow the cell wall to yield to that force and permit expansion. In Arabidopsis, and other higher plants, there is mounting evidence that a link from the instructive phytohormone auxin to the cell wall pectin matrix is key in regulating plant cell expansion. While recent experiments suggest that auxin plays a role in growth of the basal plants Physcomitrella patens and Marchantia polymorpha, there is nothing known about how auxin may (or may not) link to physical changes in the cell wall. The cell walls of basal plants contain pectins; with the emergence of genome sequences and genome editing by CRISPR/Cas9 - it is a pivotal moment for exploring the ancient mechanisms of physical cell expansion. This project will focus on 1) the growth of phyllids in P. patens and 2) thallus growth in M. polymorpha, with particular emphasis on how auxin and its responses relate to changes in cell wall biochemistry and mechanical properties. Later stages of the project would involve: identification of transcriptional changes associated with growth (RNAseq), CRISPR/Cas9-mediated genome editing of genes of interest involved in auxin and cell wall biology, and characterization of such transgenic plants. There is room for expansion and change in the project at the Ph.D stage.
People |
ORCID iD |
| Siobhan Braybrook (Primary Supervisor) | |
| Giulia Arsuffi (Student) |
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| BB/M011194/1 | 01/10/2015 | 31/03/2024 | |||
| 1643505 | Studentship | BB/M011194/1 | 01/10/2015 | 30/09/2019 | Giulia Arsuffi |
| Description | This award funded my PhD programme. I have written up my research in my PhD thesis and I am now waiting for my defense. During the past years, I tested the effect of a wide range of conditions on the growth of the early land plant model Marchantia polymorpha and identified an optimal set of environmental conditions for Marchantia culture and growth tracking. I also profiled the cell wall composition of Marchantia and foud pectin to be an abundant component of the wall of this early land plant. I have recapitulated others' results that auxin modulates growth in early land plants and I have built on that knowledge to show that pectin might have an equally dramatic effect on Marchantia growth. In accord with these findings, the key enzymes involved in pectin biochemical changes (PMEs) were found to be differentially expressed in growing areas compared with areas which had ceased growth. I characterised the member of the PME family which showed the starkest difference in expression and found that its loss causes defects in growth of baby Marchantia clones (gemmae) and increased susceptibility to pathogen infection. I also reconstructed the phylogenetic history of the PME family across several land plant species and found that this family may have acquired novel specific functions as new plant families emerged. Finally, I have shown the limitations of an antibody-based approach to the characterisation of the cell wall of bryophytes. |
| Exploitation Route | The characterisation of growth conditions for the early land plant model Marchantia polymorpha is a resource for other researchers using this model, who can now browse the set of conditions to choose what is best suited to the kind of manipulation the wish to carry out. |
| Sectors | Agriculture, Food and Drink |
| Description | IMTC2 |
| Organisation | University of Kyoto |
| Department | Graduate School of Biostudies |
| Country | Japan |
| Sector | Academic/University |
| PI Contribution | I shared the knowledge from our team about how to culture Marchantia as a model system and how to keep good collaboration networks through the same tools used by OpenPlant (BBSRC-funded synthetic biology initiative). |
| Collaborator Contribution | The Kohchi and Araki lab gave the opportunity to a few participants to visit their facilities and receive 3 weeks of training on how to exploit Marchantia as a model system, including techniques and bioinformatics resources. They also provided some constructs made by them for doing transgenic work in Marchantia. |
| Impact | As a result of this collaboration, I now have a mutant line which is helping me dissect the molecular mechanism behind my research question. This collaboration also put all of the participants in touch with the rest of the community. So far, only academic impact has resulted from this collaboration. |
| Start Year | 2016 |
| Description | SB in UCLA |
| Organisation | University of California, Los Angeles (UCLA) |
| Country | United States |
| Sector | Academic/University |
| PI Contribution | My previous PhD supervisor moved from my current university (Cambridge) to another one (UCLA). We still discuss projects, methods and advances in the field. |
| Collaborator Contribution | My supervisor designed the project and was my mentor for the first two years of the PhD programme. She is now a collaborator of the new team I joined. |
| Impact | The collaboration has just been established (Jan 2018) and so it is too early to say. |
| Start Year | 2018 |
| Description | OpenPlant Forum 2017 |
| Form Of Engagement Activity | A formal working group, expert panel or dialogue |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Professional Practitioners |
| Results and Impact | OpenPlant Forum is an annual open meeting for plant synthetic biology organised by the OpenPlant partners: University of Cambridge, John Innes Centre and the Earlham Institute. During the course of the Forum we explored new ways of exploiting genetic tools, automation, open international exchange, DIY/maker approaches and more to develop globally accessible synthetic biology research and teaching resources. I was personally involved in organising the networkiing BBQ on the final day of the Forum. We had a great mix of people from academia, startups, patenting law and more sectors intermingle and discover new ways of collaborating both in the formal context of the presentations and poster session and the informal get-togethers like the BBQ. |
| Year(s) Of Engagement Activity | 2017 |
| URL | https://www.openplant.org/events-calendar/2017/7/24/openplant-forum |
| Description | Science Festival - Univeristy of Cambridge |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | Regional |
| Primary Audience | Public/other audiences |
| Results and Impact | Families from Cambridge and the towns close by came to see the Plant Sciences Marquée during the Science Festival period and reported a shift in opinion about the research that gets carried out on plants. They did not think that so many mechanisms were shared with animals and that we knew so much about plant development. |
| Year(s) Of Engagement Activity | 2017 |
| Description | Student Masterclass |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | Local |
| Primary Audience | Schools |
| Results and Impact | A group of students from different schools in Cambridge attended a talk by a researcher in the discipline of Plant Sciences and gathered to discuss what was said and how it relates to a major contemporary and/or future challenge. Under the supervision of a PhD student mentor (myself and others), the high school students then devised a strategy to tackle this major challenge partly via research and technology and partly via engagement and policymaking. The students, who mostly joined in order to see what it is like to do research in biology, reported being more aware of 'what makes a good scientist' and of how interesting and impactful plant science research can be. |
| Year(s) Of Engagement Activity | 2018 |
| Description | SymBLS 2017 |
| Form Of Engagement Activity | A formal working group, expert panel or dialogue |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Postgraduate students |
| Results and Impact | The Symposium for Biological Life Sciences aims to bring together graduate students across a variety of biological disciplines and many different Colleges and Institutes in Cambridge, to share their research experiences. We invited excellent researchers, science communicators, clinicians, physicists and experts on commercialisation to give graduates an insight into the possibilities of various careers in Science. All in all, the syposium was well received with feedback including: "Great atmosphere, enjoyed the variety of topics discussed" and "Extremely enjoyable. Well organised!" Some participants suggested that we include more student talks, so as we pass on the baton to the next year's organisers we hope they can rise to the challenge! |
| Year(s) Of Engagement Activity | 2017 |
| URL | https://www.babraham.ac.uk/about-us/impact/impact-blog/blog/3/tagged/bioinformatics/blog/2017/09/cor... |