Impacts of heat stress on yield and seed quality in oilseed rape: analysis of the dynamic development of seed storage compounds

International audienceMany studies pointed out the deleterious effect of high temperatures during the crop reproductive stage on seed yield and quality. However, the response of plants to repeated stressing events remains poorly understood, especially in a context of climate change characterized by the increased frequency of extreme events, such as spring and summer heat waves. Although genetic improvement and management practices are relevant tools of adaptation strategies, this study aims at providing insights of stress memory effects in acclimation schemes. Prior results in oilseed rape have shown that an effective thermos-sensitizing sequence must consider i) the optimal temperature of the compound biosynthesis process, and ii) the synchrony between the temperature stress and the period of biosynthesis of the targeted storage compound. In the present study, harvests throughout the reproductive phase were performed to monitor the evolution of the main storage compounds used to determine seed nutritional quality in oil crops i.e., fatty acids and proteins which are the major criteria for edible oil and cakes used in human and animal consumption, respectively. These results should provide a better understanding of the compound specific critical periods in terms of timing, duration and intensity, in the perspective of providing thermo-sensitizing protocols to maintain or even increase seed yield and quality under climate change conditions