Seed biology and biotechnology
A major area of interest in the lab is the regulation of ion homeostasis by a family of intracellular Na+/H+ antiporters in the model plant Arabidopsis.
Overexpression of many of these family members leads to increased salt tolerance, but the mechanisms for this resistance is poorly understood. We have recently shown that two of these antiporters are required for normal plant development and have roles in intracellular protein trafficking. These antiporters regulate the pH of intracellular compartments, and influence ion sensitivity and protein trafficking by interacting with specific components of the protein trafficking, sorting and recycling machinery. We have recently shown that these antiporters affect the processing an accumulation of seed storage proteins and other vacuole localised proteins, and this suggests that pH regulation is likely to be important for seed development and grain quality in crop species.
Seed storage protein synthesis and mobilisation
Seed storage proteins accumulate in the seeds of all major food crops. In many plant species, the amount and quality of seed proteins is a critical determinant of their nutritional properties. The synthesis during embryo development, and the subsequent mobilisation (breakdown) of these nitrogen rich proteins during germination is crucial for seedling establishment.
This project will investigate the mechanism of seed storage protein biosynthesis and mobilisation during germination in barley and will determine if altering the normal biosynthesis of seed storage proteins leads to changes in protein content and improved nutritional properties. It will use a combination of sub-cellular fractionation to separate protein storage vacuoles, proteomics to identify proteins that are mis- localised and/or mis-processed in mutants with trafficking and processing defects, or in plants that overexpress components of the sorting machinery.