Manipulating photosynthesis and photoprotection in tropical rice
Dr Erik Murchie, University of Nottingham, UK
Wednesday 12 May 2010, 1600-1700
Furness Lecture Theatre 2
Centre for Sustainable Agriculture Seminar
Rice is a major source of calories for people in many parts of the world. Raising the rate of biomass production in rice crops is an important target for the improvements in yield and yield potential that will be required during the coming decades. Tropical rice is frequently subjected to high temperatures and high irradiance levels and the saturation of photosynthesis is common. We have been analysing the regulation of photosynthesis in both optimal and sub- optimal conditions. In particular, we are interested in the dynamic efficiency of photosynthesis and potential limitations placed on carbon assimilation by fluctuating environmental conditions and on the effect of photooxidative stress responses induced by high tropical irradiance levels.
Field data shows substantial down-regulation of photosynthesis and induction of photoprotective processes in rice under high irradiance in both optimal and suboptimal conditions. We have linked this with lab experiments where we have identified genes involved in short and long term responses to high irradiance. We have identified phenotypes where the down-regulation of photosynthesis is compromised: modelling predicts that this will have an impact on carbon gain at the canopy level. We are using these lines to quantify the impact of photoprotection at the canopy level and determine the optimal level of photoprotection for rice biomass production.