Do pea nodulated roots have a memory like a sieve or like an elephant when faced with recurrent water deficits ?

Abstract

National audienceIn the current context of climate change, periods of water deficit occur more frequentlyalong the crop cycle, leading to high yield losses. To limit the negative impact of recurrentwater deficits, plants can adapt, via the mobilization of “stress memory”, allowing them torespond to a subsequent stress in a faster and/or more intensive manner. After a first stressevent, plants can keep an imprint of this stress via the induction of epigenetic (e.g. memorygene regulation), physiological (e.g. stomatal closure) and molecular (e.g. compoundaccumulation) changes. When maintained between two stress periods, these changes mayprepare plants for a subsequent water deficit.This work addresses the potential role of stress memory in plant adaptation to recurrent waterdeficits with a special focus on plant hydro-mineral uptake by roots. For this purpose, anexperiment was conducted on the high throughput phenotyping platform (4PMI, Dijon, France),where several frequencies of water deficits were applied to pea plants. An integrativeapproach, including a structure-function ecophysiological framework characterizing planthydromineral nutrition (nutrients and beneficial elements), enriched with root and noduletranscriptomic analyses (RNA-seq), revealed the mechanisms underlying the “memory effect”throughout the plant cycle. We will discuss the role of memory genes during recurrent stressesand plant strategies to acquire water as well as macro- and micro-nutrients more efficientlyduring recurrent stresses. This work offers the new perspective of considering plant memoryin the design of ideotypes better adapted to multiple stress events in a context of climatechange.Study conducted in the framework of the EAUPTIC project, supported by the “Fond UniqueInterministériel" (n° 3870401/1), BPIFrance (n° DOS0097244/00), the Regional Council ofBurgundy (n° DOS0133465/00), Dijon Metropole (n° CONV-DM2018-118-20180820), and theFonds Européen de Développement Régional (n° 2018-6200FEO003S01889)