Pea Efficiency of Post-drought Recovery Relies on the Strategy to Fine-Tune Nitrogen Nutrition

Abstract

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 (Pisum sativum), 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 13 CO 2 and 15 N 2 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 finetuning of nodule formation during the post-stress period is essential for efficient drought resilience in pea leading to yield stability.

Variation in persistency, postdrought recovery and root characteristics in a tall fescue germplasm under interactive effects of exogenously applied salicylic acid and water stress

“…Postdrought recovery can certainly be decisive for drought resilience and yield stability. This highlights the importance of taking into consideration the mechanisms underlying plant recovery to improve crop stress resilience (Couchoud et al., 2020). In this study in the fourth year (2018), all genotypes were assessed for postdrought recovery by withheld irrigation from all previous treatments (the combination of three irrigated regimes and two salicylic levels) for two months.…”

Changes in Metabolic Profiles of Pea (Pisum sativum L.) as a Result of Repeated Short-Term Soil Drought and Subsequent Re-Watering

“…Metabolic, transcriptomic, and proteomic responses of the plant to repeated drought/re-watering cycles appear to play a key role in effective recovery from this stress [35]. Therefore, researchers have attempted for many years to approximate and elucidate the responses of plant species to this common and complex stress [34,36,37,[81][82][83]. The results of these studies showed that plants can strengthen their defenses by retaining information from previous stress periods [35].…”

Drought Stress Memory at the Plant Cycle Level: A Review

“…To that end, we propose a conceptual analysis framework ( Figure 3 ) including stress memory, stress forgetfulness and recovery memory that could help in understanding the dynamics of these processes. This conceptual framework follows the general concept initially developed by Couchoud et al [ 61 ], which involves the characterization of different parameters during both water stress and recovery periods: impact of the first stress, dynamics of the recovery after each stress, and duration of stress memory. Finally, a better characterization of the regulatory dynamics underlying stress memory would make it possible to predict plant responses to multiple stresses based on process-based modelling.…”