Heterotrimeric G-protein α subunit (LeGPA1) confers cold stress tolerance to processing tomato plants (Lycopersicon esculentumMill)

Background Tomatoes (Lycopersicon esculentumMill) are key foods, and their molecular biology and evolution have been well described. Tomato plants originated in the tropics and, thus, are cold sensitive. Results Here, we generatedLeGPA1overexpressing and RNA-interference (RNAi) transgenic tomato plants, which we then used to investigate the function ofLeGPA1in response to cold stress. Functional LeGPA1 was detected at the plasma membrane, and endogenousLeGPA1was highly expressed in the roots and leaves. Cold treatment positively induced the expression ofLeGPA1. Overexpression ofLeGPA1conferred tolerance to cold conditions and regulated the expression of genes related to the INDUCER OF CBF EXPRESSION-C-REPEAT-BINDING FACTOR (ICE-CBF) pathway in tomato plants. In theLeGPA1-overexpressing transgenic plants, the superoxide dismutase, peroxidase, and catalase activities and soluble sugar and proline contents were increased, and the production of reactive oxygen species and membrane lipid peroxidation decreased under cold stress. Conclusions Our findings suggest that improvements in antioxidant systems can help plants cope with the oxidative damage caused by cold stress, thereby stabilizing cell membrane structures and increasing the rate of photosynthesis. The data presented here provide evidence for the key role ofLeGPA1in mediating cold signal transduction in plant cells. These findings extend our knowledge of the roles of G-proteins in plants and help to clarify the mechanisms through which growth and development are regulated in processing tomato plants.