Final Report Summary - SUMORICE (SUMOrice: Exploiting an emerging protein modification system, SUMOylation to boost rice yield during drought and salt stress)
To feed 9 billion people by 2050 is an unprecedented challenge. Rice is the food source for the majority of the world's population but also a model for cereals. Drought and related high salinity during essential periods of plant growth affects nearly all crops including the major cereals such as rice causing drastic yield losses. A major goal of plant biology is to develop crop cultivars that are "drought and salt resistant", defined as those that have higher yields than standard cultivars under these environmental stresses. However plant responses to drought and salinity are overlapping and complex involving many physiological pathways controlled by cascades of molecular networks. This makes engineering drought and salt resistance in crops possible but very challenging unless we identify molecular mechanisms (‘Master’ co-ordinators) that can influence multiple signalling networks to produce an integrated stress response. Crop improvement programmes that target these ‘Master’ co-ordinators will have the greatest potential for yield increase. We have discovered that SUMOylation, an emerging protein modification mechanism can be recruited to co-ordinate multiple molecular response pathways to dramatically improve Arabidopsis growth on high salinity and during drought stress, a model but non-crop plant. This groundbreaking and exclusive discovery ideally places us to exploit this finding to generate stress resistant crops. So far we have shown that this system operates in a very similar way in the rice crop. We shown that this SUMO modification system allows plants to sense water availability in soil and promote root growth towards it. This is a breakthrough discovery in plants and will pave the way to generating crops better suited to a changing climate.