Acetic acid enhances drought tolerance more in female than in male willows

Abstract

Drought is an important stress factor that limits plant growth and development. Female willows generally display stronger drought tolerance than males. The application of exogenous acetic acid (AA) has emerged as an efficient and eco‐friendly approach to facilitate drought tolerance in willows. However, whether AA exerts sexually different effects on willows remains undefined. In this study, we comprehensively performed morphological and physiological analyses on three willow species, Salix rehderiana, Salix babylonica, and Salix matsudana, to investigate the sexually different responses to drought and AA. The results indicated that willow females were more drought‐tolerant than males. AA application effectively enhanced willows' drought tolerance, and females applied with AA displayed greater root distribution and activity, stronger osmotic and antioxidant capacity and photosynthetic rate but less reactive oxygen species, or abscisic acid‐mediated stomatal closure than males. In addition, AA application enhanced the jasmonic acid signaling pathway in females but inhibited it in males, conferring stronger drought defense capacity in female willows than in males. Overall, AA application improves drought tolerance more in female than in male willows, further enlarging the sexual differences in willows under drought‐stressed conditions.

Female-biased population sex ratios caused by genetic rather than ecological mechanisms

“…In further Salix species, however, female bias was also present in almost all populations but varied along biotic or abiotic environmental gradients (Bürli et al, 2022;Dawson & Bliss, 1989;Dudley, 2006;Elmqvist et al, 1988). In many female-biased Salix species, sexes differ in stress tolerance (e.g., Dawson & Bliss, 1989;Xia et al, 2023) and pathogen damage (e.g., Alliende, 1989;Boecklen et al, 1990;Moritz et al, 2016). It is unclear though, whether these differences contribute to female bias or, alternatively, are a consequence of physiological differences between sexes.…”