Developmental and genotypic determinants of macro and micronutrient distribution across faba bean seed tissues

Faba bean (Vicia faba L) is the UK’s most important pulse crop, valued for its high nutrient density, strong nitrogen-fixing capacity and agronomic versatility and is in strong demand as a sustainably sourced raw material for both animal feed and meat and dairy alternative food manufacture. The mature faba bean seed consists of cotyledons, which represent the main storage tissue of the seed, the embryonic axis, containing plumule and radicle primordia, and the seed coat, enveloping and protecting the other two tissues, and regulating exchanges with the external environment. The different biological roles of these tissues underpin their compositional differences: the cotyledon being enriched in protein and starch as a nutrient reserve to power germination, while the seed coat is enriched in fibre and phytochemicals to enhance its function as a protective sheath.

While it is well known that pulses are a good source of protein and minerals, little is known about spatial distribution of these components in the seed. This is relevant because of the growing interest in using pulses for the formulation of bakery foods, with the aim to enhance their nutritional quality and sustainability [1]. This requires milling of the pulse to a flour, and an in-depth knowledge of macro and micronutrient distribution within the different parts of the seed would enable tailoring the milling method and further processing to achieve final products with specific nutritional and organoleptic characteristics. This is particularly relevant for faba bean, given the large genetic variability in seed size and shape available in this species and the possibility to obtain markedly differentiated end products. Understanding what determines the patterns of distribution of different seed components would also open the way to genetic improvement of seed composition and processing properties.

This project aims to address knowledge gaps in:  

• the distribution of macro and micronutrients in faba bean seeds across the different tissues of the seed and/or regions within the cotyledon tissue.

• whether patterns of distribution reflect the timing of synthesis and deposition of the different components and/or their turnover relative to cell division, expansion and differentiation events.

The student will start addressing these questions by studying tissue and time-resolved variation in gene expression and compositional differences through seed development on a panel of faba bean genotypes with diverse seed structure and composition.

This will be followed by in situ identification and quantification of proteins via light microscopy combined with Raman microscopy and subsequent laser-ablation ICP-MS analysis to map mineral distribution. Finally, key macro-and micronutrients with non-random distribution will be mapped throughout development and the fate of different tissues tracked through the milling process.

This project is one of two contemporaneous and complementary PhD projects both linked to the ongoing 5-year Defra-funded Pulse Crop Genetic Improvement Network (the other project is entitled “Molecular interactions between the bruchid beetle and developing faba bean seed.”)

Dr Tosi’s lab conducts pioneering research into the relationship between seed development and technological quality [2,3] and in the exploration of variation in the development [4] and nutritional properties [5] of the faba bean seed. The University of Reading boasts excellent molecular, imaging and analytical laboratories as well as controlled plant growth facilities to support the research and the appointee will join a vibrant and mutually supportive team of postdocs, PhDs and technicians all exclusively focused on different aspects of faba bean functional genomics, biology and breeding.

The studentship will start at the latest by October 2025.

[1] Lovegrove et al (2023) Nutrition Bulletin https://doi.org/10.1111/nbu.12601

[2] Shewry et al (2020) J Cereal Sci https://doi.org/10.1016/j.jcs.2019.102869

[3] Lovegrove et al (2020) Cereal Chemistry https://doi.org/10.1002/cche.10316

[4] Warsame et al (2022) J Agr Food Chem https://doi.org/10.1021/acs.jafc.2c02061

[5] Warsame et al (2020) J Agr Food Chem https://doi.org/10.1021/acs.jafc.0c02927

Funding

This studentship is for three years and provides full UK/home fees, a stipend at UKRI-BBSRC standard rates (currently £19,237 for 2024/25) as well as dedicated funds for consumables, training and travel.

Eligibility

Candidates must hold at least a BSc (Hons) 2.1 or higher in a relevant subject.

To be classed as a home student, candidates must meet the following criteria and the associated residency requirements:

• Be a UK or Irish National or,

• Have settled status or,

• Have pre-settled status or,

• Have indefinite leave to remain or enter

How to apply

To apply for this opportunity, please send a CV and covering letter covering your motivations for pursuing a higher research degree and the reasons why you think this is the project for you to: p.tosi@reading.ac.uk. Applications will be assessed at fortnightly intervals starting 15/02/2025 and screening will continue until a suitable candidate is identified.

Please also complete an online application for a PhD in Crop Sciences in the School of Agriculture, Policy and Development. When applying, if the application system prompts you to submit a research proposal, please paste in the project title and move on to the next step in the application. When the system asks about funding, please enter ‘DRC24-133‘ in the relevant box.