Plant responses to low oxygen: molecular and physiological mechanisms to improve tolerance

Low oxygen and flooding are environmental stresses for many natural and man-made ecosystems worldwide. They have a dramatic effect on the growth and yield of crop plants because most of economically important species are intolerant to flooding. Moreover, sensitive crops, like maize (Zea Mays), rice (Oryza sativa) and tomato (Solanum Lycopersicum L), are fundamental in the feeding of people that lives in country subject to natural disasters. The exploration of natural variation in strategies that improve O2 and carbohydrate status during flooding provides valuable resources for the improvement of crop endurance of an environmental adversity that is enhanced by global warming. The knowledge of physiological and molecular mechanisms involved in plant stress response to flooding will be important, in order to discover and isolate tolerant cultivars able to get over adverse conditions and to help the development of a sustainable agriculture. For this purpose, my research was aimed to understand the physiological and molecular mechanisms behind some important adaptive traits of rice plants that are able to withstand periods of partial or even complete submergence. Moreover, an additional goal was to identify and characterize genes involved in response to O2 deficiency, in order to understand the perception and signal transduction behind the stress. This second part of the work was done on Arabidopsis plant, chosen as model for the plant molecular biology and thus having the availability of many molecular tools.