Cultivating resilience: Use of water deficit to prime peanut production and improve water stress tolerance

Abstract

Regulated deficit irrigation is a potential strategy for priming peanut plants to improve their acclimation to water stress. To assess possible effects of priming and develop an effective water stress priming strategy, greenhouse experiments were conducted to compare primed and non-primed peanut cultivars, C7616 and TUFRunner ‘511′™, to subsequent water stress. Plants were divided into 1) controls with daily irrigation to field capacity throughout the entire growth cycle, 2) non-primed plants receiving daily irrigation up to 55 to 65 days after planting (DAP), followed by exposure to mid-season water stress, and 3) primed plants that received 50 % of the control irrigation either from 5 to 45 DAP (long-term priming), or 20–45 DAP (short-term priming), followed by mid-season water stress at 55 to 65 DAP. An automated physiological phenotyping platform was used to control irrigation and continuously monitor soil water content, whole-plant transpiration and water use. Single-leaf measurements of net CO₂ assimilation, stomatal conductance, and transpiration were taken periodically. Plant biomass and biomass partitioning were also determined. Results indicated that primed plants grown under water deficit exhibited either reduced (acclimated) or intensified (sensitized) physiological stress responses upon subsequent water stress. Timing and duration of the priming period played a key role in modulating plant phenotypic plasticity, which varied by genotype, suggesting that priming could be in part genetically controlled.