Shaila Satu

Profile

Project Title: The importance of photosynthesis in awns and developing seeds of barley (Hordeum vulgare) for grain yield and seed viability.

Summary: Photosynthesis converts light energy to transform CO2 into soluble carbohydrates, which are then utilized for plant  growth and maintenance. Most research has focused on leaf photosynthesis with a minimal understanding of potential carbon assimilation in nonfoliar green tissue including flower, stem, awns, developing seed etc. and its contribution to yield and seed quality. In comparison to leaves, we know almost nothing about the photosynthesis in nonfoliar green tissue. We aim to discover why photosynthesis in awns and developing seeds is important for grain yield and seed viability.

Cereal grains form the staple of most human (and increasingly livestock) diets worldwide. During cereal grain development, the awns and developing seeds (which are among the highest parts of the plant and can therefore receive a lot of light) are capable of photosynthesis. Previous studies have indicated that photosynthesis in these tissues can be important for grain yield and seed viability. The reasons for this remain unclear. It is suggested that unique, but unknown, features of the leaf spikes (awns) enable them to make a large contribution to grain filling, especially in drought conditions. Seed photosynthesis is understood in terms of supporting respiration in the developing seed (by supplying O2 and recovering the CO2 lost during respiration). Remarkably, light harvesting and photosynthetic electron transport, which supply the energy for photosynthesis, have never been thoroughly investigated in these extraordinarily important tissues. 

We want to understand how and why this is the case, and to test a new hypothesis: that free radicals produced during photosynthetic electron transport, are exploited by the developing seed as developmental triggers, and integrate with hormone signaling to control seed development.  

Supervisor:

• Dr Guy Hanke

Research