Séminaire Ecobio - Cécile Jacques (Ecobio)
Climate change induces increasingly frequent periods of water deficits during the crop cycle. In this context, several studies highlighted the beneficial effect of priming of a first stress on the response to a second stress by the induction of a transcriptional memory. However, little is known about the effect of water stress memory on the different physiological processes of the plant. So, it seems important to highlight the plant memory at various levels ranging from the expression of genes to the physiological traits of plant. To highlight the potential beneficial effect of memory during recurrent water stress "memory genes" within the root system, metabolites and physiological processes related to plant hydro-mineral nutrition were characterized. These analyses revealed that a transcriptional memory was established in pea roots, via the regulation of genes involved in epigenetic marks. In addition, three antioxidants were specifically accumulated in roots during recurrent water stress: mannitol-1-phosphate, 3,4-dihydrobenzoic acid and isorhamnetin. And finally, an ecophysiological imprint of the stress involved in the memory of stress in pea was put forward: the increase of nodulation initiation during rewatering period. Taken together, these results provide new insights for understanding water stress memory in pea plants and offer new insights into the resilience of pea to recurrent water stress events for plant breeding strategies.