Characterization of WHIRLY1 functions in cereal crops

Lead Research Organisation: University of Leeds
Department Name: Inst of Integrative & Comparative Biolog

Abstract

Chloroplasts are major sensors of environmental change, particularly stress perception. Plants growing in fluctuating environments require coordinated regulation of photosynthesis, growth and defence. The current lack of understanding of how chloroplast and nuclear gene expression are co-regulated under abiotic stress conditions is a major impediment to crop improvement. This project, which concerns the functional characterization of WHY1, is based on recent work in the applicant's laboratory that demonstrated this protein as an important player in chloroplast and nuclear biology, with roles in signalling between these organelles. WHY1 is a member of the WHIRLY family of single-stranded DNA-binding proteins that is found in both plastids and the nucleus, fits well into BBSRC's strategic priorities in the area of "sustainably enhancing agricultural production", particularly in the topic of "greater resilience of crops to abiotic stresses". WHY1 acts as a transcription activator for pathogen-related gene expression in the nucleus and as a repressor for the kinesin-like protein 1 that modulates telomere length. In chloroplasts, WHY1 is required for plastid genome stability and plastid gene transcription. However, much remains uncertain concerning how WHY1 participates in the regulation of leaf development and stress tolerance. Moreover, WHY1 appears to be essential for plastid ribosome biogenesis in maize but not in other species. This project combines the expertise of the Foyer lab on WHIRLY proteins with that of Biogemma in cereal transformation and the creation of new traits suitable for plant breeders. These studies will provide new knowledge concerning WHY1 functions in cereals and shed new light on chloroplast to nucleus retrograde signalling mechanisms under optimal and stress conditions. The objectives of this proposal are:
1) To produce and characterise transgenic RNAi wheat plants lacking WHY1. (Milestone 1: generation of transgenic wheat lines with altered WHY1 expression).
2) To generate and characterise transgenic maize plants over-expressing WHY1 in either the mesophyll or bundle sheath chloroplasts. (Milestone 2: generation of transgenic maize lines with altered WHY1 expression)
3) To determine the effects of modified WHY1 expression on plant responses to low nitrogen availability, drought and high light stresses to link these changes to chloroplast to nucleus signalling (Milestone 3: Generation of transcript and metabolite profile data).
The transgenic lines and wild types will be used together with why1 and why2 Mu transposon-induced maize mutants to explore the roles of the WHY1 protein in the chloroplasts and nuclei of mesophyll and bundle sheath cells during leaf development in absence or presence of stress (high light, drought, low nitrogen). The mechanisms of redox regulation of the WHY1 protein in chloroplasts will be characterised. In addition to physiology, biochemistry and cell biology approaches to study photosynthesis and leaf development, the student will use RNAseq and metabolite profiling on specific lines under selected conditions. qPCR techniques and screens with lincomycyin and other inhibitors will be used to characterise chloroplast to nucleus signalling pathways. The effects of WHY1 deficiency on root phenotypes will also be compared in wild type and transgenic lines grown under optimal and stress conditions. Field behaviour and yield impacts will be assessed in selected lines

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
BB/M011151/1 01/10/2015 30/09/2023
1970896 Studentship BB/M011151/1 01/12/2017 28/02/2022 Rachel Taylor
 
Description iCASE partnership with Biogemma 
Organisation Limagrain
Country France 
Sector Private 
PI Contribution iCASE partnership with Biogemma, now Limagrain. Contribute to their knowledge of WHIRLY and its interactors.
Collaborator Contribution Provided plants and seeds to work on as well as growth spaces.
Impact Outcomes are knowledge of WHIRLY in cereal crops wheat and maize.
Start Year 2017
 
Description Demonstrating to Undergraduates 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Undergraduate students
Results and Impact I encourage students to consider the protocol before they arrive, read background information and use the VLE to allow engagement with the research-based learning of the Leeds curriculum.
I also use my time as a demonstrator both in teaching and marking providing feedback to students so that they can improve their education.
Year(s) Of Engagement Activity 2018,2019,2020
 
Description Discovery Zone 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact Set up a discovery zone stall aimed at inspiring science education in 11-14 year olds from schools in Yorkshire.
Around 200 pupils attended every year from a range of schools. The schools have reported interest in science amongst pupils since the event.
Year(s) Of Engagement Activity 2018,2020
 
Description Realising Opportunities Tutor 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact I mentored for Realising Opportunities, a programme for A-Level students from disadvantaged backgrounds to gain a better understanding of their chosen subject at university. During this course, I helped students develop an essay, assessed progress and marked progress. It is important when providing education to students across different cultures that different learning opportunities are provided; therefore, I gave students access to an internet learning portal, provided my email and face-to-face meetings.

Many of my students across the years have used their essay in Realising Opportunities to gain a place at university.
Year(s) Of Engagement Activity 2018,2019,2020