Silencing of SlERF.F5 affects tolerance to drought, salt and low-temperature stresses in tomato

Abiotic stresses, including drought, high salinity, and low temperature, present significant challenges to the growth and yield of tomato plants. The AP2/ERF family of genes is integral to plant stress responses; however, the specific role of SlERF.F5 in conferring stress resistance in tomatoes remains to be elucidated. In this study, we constructed SlERF.F5-RNAi tomato plants by RNAi technology and treated them with drought, salt and low temperature. Physiological index analysis showed that the stress resistance of SlERF.F5-RNAi plants was significantly enhanced compared with wild-type (WT) plants. Specifically, under stress conditions, the relative water content of the silenced plants was significantly higher; the relative conductivity and malondialdehyde (MDA) content were significantly reduced. In addition, the chlorophyll content of SlERF.F5-RNAi plants was higher. Quantitative real-time PCR (qRT-PCR) analyses further indicated that the silencing of SlERF.F5 led to the activation of various stress response genes, with up-regulation observed in genes associated with osmotic regulation (P5CS) and antioxidant defense mechanisms (Cat1 and Apx2). Under conditions of low temperature stress, the expression of the SlCOR gene in SlERF.F5-RNAi plants was upregulated, potentially facilitating the accumulation of hydrophilic COR proteins and thereby mitigating membrane lipid peroxidation damage induced by low temperatures. This study is the first to establish that SlERF.F5 serves as a negative regulatory in tomato’s response to drought, salinity, and low temperature stress. The silencing of SlERF.F5 enhanced tomato resistance to these abiotic stresses by modulating the expression of stress-responsive genes and preserving cell membrane integrity. These findings not only offer novel insights into the role of ERF family genes in plant stress adaptation, but also identify potential gene targets for the molecular breeding of stress-resistant tomato varieties.