Background: Tomatoes (Lycopersicon esculentum Mill) 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 generated LeGPA1 overexpressing and RNA-interference (RNAi) transgenic tomato plants, which we then used to investigate the function of LeGPA1 in response to cold stress. Functional LeGPA1 was detected at the plasma membrane, and endogenous LeGPA1 was highly expressed in the roots and leaves. Cold treatment positively induced the expression of LeGPA1. Overexpression of LeGPA1 conferred 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 the LeGPA1-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 of LeGPA1 in 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.

Background Tomatoes (Lycopersicon esculentum Mill) are key foods and are also commonly explored in studies of molecular biology and evolution. The plant originates from the tropics, thus is sensitive to cold, and its growth and development are easily affected by cold stress. Results In this study, LeGPA1 was cloned from tomato leaves and used to generate LeGPA1-overexpressing and RNA-interference-expressing transgenic plants. The function and expression of LeGPA1 in response to cold stress were assessed. Subcellular localization analysis identified functional LeGPA1 on the plasma membrane. Spatiotemporal expression analysis revealed that endogenous LeGPA1 was highly expressed in the roots and leaves. Cold treatment positively induced the expression of LeGPA1. The overexpression of LeGPA1 conferred tolerance to cold conditions and regulated the expression of genes related to the ICE(INDUCER OF CBF EXPRESSION)- CBF(C-REPEAT-BINDING FACTOR) pathway in tomato plants. In the LeGPA1-overexpressed transgenic plants, antioxidant enzyme activity and soluble sugar and proline contents increased, and the production of reactive oxygen species and membrane lipid peroxidation decreased under cold stress. Conclusions This suggests that better antioxidant systems can cope with oxidative damage caused by cold stress, thereby stabilizing cell membrane structures and increasing the rate of photosynthesis. These findings provide evidence for the key role of LeGPA1 in 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 processing tomato plants can regulate growth and development.