Couchoud Mégane, Salon Christophe, Girodet Sylvie, Jeudy Christian, Vernoud Vanessa, Prudent Marion
Agroécologie, AgroSup Dijon, INRAE, Université de Bourgogne, Université Bourgogne Franche-Comté, Dijon, France.
Front Plant Sci. 2020 Feb 27;11:204. doi: 10.3389/fpls.2020.00204. eCollection 2020.
As drought is increasingly frequent in the context of climate change it is a major constraint for crop growth and yield. The ability of plants to maintain their yield in response to drought depends not only on their ability to tolerate drought, but also on their capacity to subsequently recover. Post-stress recovery can indeed be decisive for drought resilience and yield stability. Pea (), as a legume, has the capacity to fix atmospheric nitrogen through its symbiotic interaction with soil bacteria within root nodules. Biological nitrogen fixation is highly sensitive to drought which can impact plant nitrogen nutrition and growth. Our study aimed at dynamically evaluating whether the control of plant N status after drought could affect nodulated pea plant's ability to recover. Two pea genotypes, Puget and Kayanne, displaying different drought resilience abilities were compared for their capacity to tolerate to, and to recover from, a 2-weeks water-deficit period applied before flowering. Physiological processes were studied in this time-series experiment using a conceptual structure-function analysis framework focusing on whole plant carbon, nitrogen, and water fluxes combined to two CO and N labeling experiments. While Puget showed a yield decrease compared to well-watered plants, Kayanne was able to maintain its yield. During the recovery period, genotype-dependent strategies were observed. The analysis of the synchronization of carbon, nitrogen, and water related traits dynamics during the recovery period and at the whole plant level, revealed that plant growth recovery was tightly linked to N nutrition. In Puget, the initiation of new nodules after water deficit was delayed compared to control plants, and additional nodules developed, while in Kayanne the formation of nodules was both rapidly and strictly re-adjusted to plant growth needs, allowing a full recovery. Our study suggested that a rapid re-launch of N acquisition, associated with a fine-tuning of nodule formation during the post-stress period is essential for efficient drought resilience in pea leading to yield stability.
在气候变化背景下，干旱日益频繁，这是作物生长和产量的主要限制因素。植物应对干旱时维持产量的能力不仅取决于其耐旱能力，还取决于随后的恢复能力。胁迫后恢复对于抗旱性和产量稳定性确实至关重要。豌豆作为一种豆科植物，能够通过与根瘤内土壤细菌的共生相互作用固定大气中的氮。生物固氮对干旱高度敏感，干旱会影响植物的氮营养和生长。我们的研究旨在动态评估干旱后对植物氮素状况的控制是否会影响结瘤豌豆植株的恢复能力。比较了两种具有不同抗旱能力的豌豆基因型Puget和Kayanne在开花前经历2周水分亏缺期后的耐受和恢复能力。在这个时间序列实验中，使用了一个概念性的结构-功能分析框架来研究生理过程，该框架侧重于全株碳、氮和水流，并结合了两个CO和N标记实验。与水分充足的植株相比，Puget的产量下降，而Kayanne能够维持其产量。在恢复期，观察到了基因型依赖的策略。对恢复期和全株水平上碳、氮和水相关性状动态同步性的分析表明，植物生长恢复与氮营养密切相关。在Puget中，水分亏缺后新根瘤的形成比对照植株延迟，并且形成了额外的根瘤，而在Kayanne中，根瘤的形成迅速且严格地重新调整以满足植物生长需求，从而实现了完全恢复。我们的研究表明，快速重新启动氮素获取，以及在胁迫后时期对根瘤形成进行微调，对于豌豆高效的抗旱性和产量稳定性至关重要。
