Transcriptional regulation of plant growth in nuclear micro domains.

To achieve "sustainable production of sufficient food to supply the world's growing population" scientists need to develop a strategy to promote plant growth by optimising light capture and energy production. One of the most dramatic developmental transitions in a plant's life cycle occurs during photomorphogenesis, when a seedling emerges from the soil and develops leaves, chloroplasts, an embryonic stem, roots and starts producing photoprotective compounds. The majority of these processes are regulated at the transcriptional level.

To fully understand the principles of transcriptional regulation of gene expression I propose to employ an innovative approach to investigating where, when and how environmental and endogenous stimuli integrate and signalling pathways cross-talk within the nucleus to coordinate the expression of genes that are essential for optimising plant growth. More specifically, we will investigate the function of a novel key nuclear signal integrator of environmental and endogenous stimuli in regulating gene expression. TZP is a nuclear component that plays a major role in integrating light, hormone and clock networks to accelerate plant growth. Plants expressing increased levels of TZP develop longer hypocotyls, petioles and stems that allow them to outperform their neighbours for light capture and energy production. Most crop plant species including soybean, rice, barley and brassicacea contain TZP orthologs in their genome, which is an indication of its functional significance across species. TZP could provide a new target for accelerating growth rates, seedling establishment and survival in economically valuable crop species. Furthermore, characterisation of highly conserved processes, such as transcriptional activation and signal integration will also contribute to the general knowledge of the regulation of gene expression in eukaryotes and facilitate the development of predictive disease screening.

The scientific scope of this research plan is encompassed within the strategic priorities of the BBSRC. Firstly, accelerating plant growth will have major applications in crop science. Secondly, the mechanism of transcriptional regulation of gene expression and nuclear compartmentalisation are fundamental and highly conserved processes among eukaryotic organisms. Findings stemming from this research proposal will have direct relevance to research on crop science as well as healthy ageing.

The focus of this research proposal is to investigate the role of novel, key regulators of gene expression with the aim to optimise plant growth and development. In particular, I propose to elucidate the mechanism of action of a new major signal integrator and transcriptional regulator of growth during photomorphogenesis. TZP is a unique nuclear protein that acts as a scaffold for integrating light, hormone and clock networks to accelerate plant growth and establish seedling development during de-etiolation. The subcellular localisation, domain content and association of TZP with RNA, transcription factors and photoreceptors indicates an active role in regulating gene expression. The concept of concentrating transcriptional machinery and inducing re-localisation of chromatin regions within punctate nuclear domains, defined as "transcription factories" has recently been established in higher eukaryotes. The existence of transcription factories and the possibility of active gene regions translocating towards areas enriched in transcriptional regulators remains to be elucidated in plants. TZP will be used as a model to examine the existence of transcription factories in plants and correlate the dynamics of global nuclear organisation with co-regulation of gene expression in response to light. Collectively, this study will characterise a potential target for improving growth rates and survival in economically valuable crop species.

Outcomes arising from this research proposal will be potentially attractive to diverse types of beneficiaries ranging from academic and research institutions, biotechnology and agriculture sectors as well as public outreach and science communication programmes. This research project will not only contribute to basic academic research and teaching but could also have applications in agriculture and pharmaceutical biotechnology. Furthermore, my hope is that findings stemming from this research plan will also contribute to the general philosophy of academic institutions in terms of research-led teaching, with the aim to enthuse the younger generation of science students.

In addition to the academic beneficiaries summarised in the previous section, this research proposal will benefit the society and the economy of the country. More specifically, societal beneficiaries will include public engagement and science communication approaches. Both the PI and the PDRA will be involved in public engagement programmes organised by the University of Glasgow (Hunterian Museum and Art Gallery) and the Gatsby Charitable Foundation to inform and educate the non-specialist audience about basic, applied and highly controversial issues such as genetically modified crops. The PI has been involved both as a PhD student and as a post-doc at the Salk Institute, in science communication programmes by explaining our lab's research interests, the model organism that we use and the approaches and facilities we use on an every day basis. In addition, the PI will provide summer projects for Undregraduatte and High School students. Such outreach initiatives provide an excellent way to inform the non-scientific community about the experimental procedures involved in the development and application of scientific discoveries to agriculture and medicine and to enthuse the younger generation to pursue a career in science.

Economic beneficiaries will develop by exploiting the potential application of new discoveries from basic science to biotechnology. Possible applications in agriculture will be pursued by actively participating in the yearly Glasgow University Industry Day event and by initiating collaborations with Crop Institutes. In the case of this study, understanding the variables and identifying the key players that promote plant hypocotyl growth in response to light, clock and hormones can be readily translated to crop species, such as the Brassica family, that are close relatives to Arabidopsis and retain all the highly conserved signalling components. Interaction and collaborations with institutes that have the facilities, funding and expertise will be established in order to perform field studies to screen and select or generate lines that show improved performance. For example, in the case of TZP, it is known that its overexpression leads to longer hypocotyls. Overexpression of the highly conserved TZP ortholog in Brassica, Rice, Soybean or other crop species, can be examined and developed to optimise crop yield.

The PI, RA and PDRAs will set an impact agenda and yearly monitor and measure the progress of the proposed objectives and milestones, which are detailed in the pathways to impact statement.