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

Abstract

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.

Heterotrimeric G Protein Signaling in Abiotic Stress

“…In contrast with the Arabidopsis results, transgenic tobacco plants overexpressing a pea Gα subunit showed increased tolerance to heat stress suggesting a positive role for the pea Gα subunit in the adaptation to heat [ 94 ]. Transgenic tomato lines either overexpressing the LeGPA1 Gα subunit or containing RNA interference constructs have been characterized for cold tolerance [ 108 ]. LeGPA1 -overexpressing lines showed increased tolerance to cold stress than WT controls while LeGPA1 -silenced lines exhibited decreased cold tolerance.…”

“…The inducer of CBF expression (ICE)-C repeat binding factor (CBF)-cold-responsive (COR) (ICE-CBF-COR) pathway controls signaling upon cold perception to regulate downstream genes involved in the production of osmoregulatory compounds [ 109 ]. Cold-treated LeGPA1 -overexpressing lines showed enhanced levels of LeICE1 , LeCBF1, and LeCOR413PM2 gene expression over WT plants resulting in elevated levels of proline and soluble sugar to protect against cellular damage, suggesting that LeGPA1 has a positive role in the adaptation to cold stress in tomato [ 108 ].…”

Genetic Transformation of Arachis hypogaea Using Novel Genes Conferring Fungal Resistance-A Review

“…This lead to the development of transgenic plants which are developed through genetic engineering techniques in which DNA is artificially inserted to get it expressed in recipient species (67). This advancement results in increased shelf life (61), elevated yield (68), improved nutritional quality (69), or enhancing capability of a variety to grow and yield against biotic (70-72) and abiotic stresses like tolerance to heat (73,74), cold (76) and drought resistance (77,78). Transformation of peanut for incorporating transgene has been started later than 1990.…”

Research Advances in Heterotrimeric G-Protein α Subunits and Uncanonical G-Protein Coupled Receptors in Plants

“…In processing tomatoes, LeGPA1 has a positive regulatory effect on cold-response gene expression. Overexpression of LeGPA1 could alleviate cell membrane damage and accumulation of ROS under low-temperature stress, which enhanced the resistance of transgenic tomato seedlings to low temperature [45]. In oilseed B. juncea, the RNAi-based suppression of Gα genes resulted in multifarious effects on plant growth and development, such as reduced growth, smaller seeds, and less seed weight.…”