Supervisor
Dr Ahmed Warsame
Brief summary
Legume seeds are a vital source of nutrients including proteins, starch, and minerals, which are essential for human nutrition. However, these nutritional components can be significantly altered under stress conditions. Additionally, legumes contain anti-nutritional compounds, such as phytic acid (PA), condensed tannins (CTs), and raffinose family oligosaccharides (RFOs), which play critical roles in plant stress adaptation. This project aims to investigate how drought-induced shifts in plant biological processes influence seed nutrient composition.
Importance of Research
Understanding how stress conditions such as drought affect seed quality and identifying the nutritional quality traits that are most sensitive to stress conditions will aid in developing both agronomic and genetic strategies to maintain or improve the nutritional properties of food crops grown in drought-prone regions.
Project Summary
Climate change is projected to affect both the yield and the nutritional quality of food crops. Drought stress, for instance, has been shown to elevate anti-nutritional compounds (e.g. phytic acid) while reducing essential minerals (e.g. iron) in legumes. These crops are naturally rich in several antinutrients, and understanding their nutritional quality under elevated stress conditions is crucial because of the growing interest in increasing their production and consumption to improve human health and environmental sustainability in the face of climate change. This project examines the extent to which drought stress modulates the accumulation of (a) major anti-nutritional compounds, (b) seed storage proteins, (c) starch, and (d) minerals in legume seeds. By elucidating these dynamics, this study will inform breeding programs on which nutritional traits should be prioritised when selecting for drought tolerance. This information can also be used to understand the molecular mechanisms underlying the changes in nutritional quality under drought stress.
What will the student do?
This project will involve the evaluation of cowpea accessions with different levels of drought tolerance for seed nutritional composition under stress and non-stress conditions. Drought stress will be imposed at different growth stages to simulate common patterns of drought occurrence in the field. During plant growth, the student will collect data on drought response-related traits, including the concentration of anti-nutritional compounds in the leaves. At maturity, in addition to yield components, a complete analysis of the chemical composition of the seeds will be performed. Based on these data, further follow-up experiments will be conducted, including transcriptomic analyses of developing seeds under stress and control conditions.
Training provided
The student will gain experience with a variety of techniques, including experimental design, biochemical assays, molecular genetics, and bioinformatics. Training in molecular biology techniques and bioinformatics will also be provided. The student will be supported by a group lab technician and any relevant training will be provided.
References
1. Boukar, O., et al., Cowpea (Vigna unguiculata): Genetics, genomics and breeding. Plant Breeding, 2019. 138(4): p. 415-424. doi: 10.1111/pbr.12554
2. Choukri, H., et al., Heat and Drought Stress Impact on Phenology, Grain Yield, and Nutritional Quality of Lentil (Lens culinaris Medikus). Frontiers in Nutrition, 2020. 7. doi: 10.3389/fnut.2020.596307
3. Hummel, M., et al., Reduction in nutritional quality and growing area suitability of common bean under climate change induced drought stress in Africa. Scientific Reports, 2018. 8(1): p. 16187. doi: 10.1038/s41598-018-33952-4
##Notes:
1. Comparing each accession under control and stress conditions will indicate the stress-related changes in seed composition.
2. Comparisons among accessions with different levels of stress tolerance will provide clues as to whether better adaptation is associated with compromised nutritional quality.
3. Understanding each nutrients response to stress will give us options for target: for instance, if PA and raffinose are both significantly increased, which one can we aim to reduce? These same is for different seed storage proteins.