The GhNAC75-GhMAPK7-3 module positively regulates drought tolerance of Gossypium hirsutum

Mitogen-activated protein kinases (MAPKs) play significant roles in plant response to drought stress. However, whether and how cotton GhMAPK7–3 regulates drought tolerance is elusive. In this report, we provide evidence that the mRNA abundance of GhMAPK7–3 clearly increased under drought conditions. Silencing GhMAPK7–3 by virus induced gene silencing (VIGS) led to marked decrease in drought resistance of cotton plants while overexpressing GhMAPK7–3 conferred enhanced drought tolerance to Arabidopsis thaliana . Moreover, the levels of malondialdehyde (MDA) and electrolyte leakage in GhMAPK7–3 VIGS plants were noticeably higher than those in the control plants, whereas the superoxide dismutase (SOD) and catalase (CAT) activities in GhMAPK7–3 -silenced plants were notably lower than those in the controls upon drought treatment. Consistently, overexpression of GhMAPK7–3 in A. thaliana caused considerable enhances in SOD and CAT activities and the reduction in the levels of MDA and electrolyte leakage under water deficiency. Additionally, GhMAPK7–3 transcription was directly promoted by the transcription factor GhNAC75. VIGS cotton plants with silenced GhNAC75 showed marked reduction in drought tolerance. In summary, our results indicate that the GhNAC75-GhMAPK7–3 module plays essential roles in improving drought tolerance of cotton plants. • GhMAPK7–3 positively regulates drought tolerance in cotton. • GhMAPK7–3 transcription is directly regulated by GhNAC75. • Silencing GhNAC75 significantly reduces drought tolerance in cotton.