The GhNAC3-GhFSD3 module positively modulates cold resistance in Gossypium hirsutum by enhancing SOD activity

Superoxide dismutase (SOD) is essential for plant adaptation to cold stress. Nevertheless, whether and how GhFSD3 modulates cold resistance in cotton remains unclear. Here, we present evidence indicating that GhFSD3 expression was significantly enhanced upon cold stress. Silencing GhFSD3 via virus-induced gene silencing (VIGS) resulted in significant reductions in the cold resistance of cotton. Conversely, over-expression of GhFSD3 in Arabidopsis thaliana enhanced its cold tolerance. Furthermore, in GhFSD3 VIGS plants, the levels of O 2 ·− , malondialdehyde (MDA), and electrolyte leakage were significantly elevated compared to the control group. In contrast, during cold exposure, the SOD activity in GhFSD3 -silenced plants was substantially reduced relative to that in the controls. Similarly, the over-expression of GhFSD3 in A. thaliana led to a notable boost in SOD activity and effectively decreased the levels of O 2 ·− , MDA, and electrolyte leakage under cold stress conditions. Furthermore, the mRNA level of GhFSD3 was directly activated by GhNAC3. VIGS mediated silencing of GhNAC3 in cotton plants resulted in a significant decrease in cold tolerance. In summary, our findings demonstrate that the GhNAC3-GhFSD3 module is crucial for enhancing the cold resistance of cotton plants. • GhFSD3 positively modulates cold tolerance in cotton. • GhFSD3 expression is directly modulated by GhNAC3. • Silencing of GhNAC3 significantly decreases cold tolerance in cotton.