Overexpression of SlGRAS40 in Tomato Enhances Tolerance to Abiotic Stresses and Influences Auxin and Gibberellin Signaling

Abstract

Abiotic stresses are major environmental factors that inhibit plant growth and development impacting crop productivity. GRAS transcription factors play critical and diverse roles in plant development and abiotic stress. In this study, SlGRAS40, a member of the tomato (Solanum lycopersicum) GRAS family, was functionally characterized. In wild-type (WT) tomato, SlGRAS40 was upregulated by abiotic stress induced by treatment with D-mannitol, NaCl, or H2O2. Transgenic tomato plants overexpressing SlGRAS40 (SlGRAS40-OE) were more tolerant of drought and salt stress than WT. SlGRAS40-OE plants displayed pleiotropic phenotypes reminiscent of those resulting from altered auxin and/or gibberellin signaling. A comparison of WT and SlGRAS40-OE transcriptomes showed that the expression of a large number of genes involved in hormone signaling and stress responses were modified. Our study of SlGRAS40 protein provides evidence of how another GRAS plays roles in resisting abiotic stress and regulating auxin and gibberellin signaling during vegetative and reproductive growth in tomato.

BrLAS, a GRAS Transcription Factor From Brassica rapa, Is Involved in Drought Stress Tolerance in Transgenic Arabidopsis

“…To date, few reports have documented a role of GRAS proteins in drought stress. For example, NtGRAS1 in tobacco (Czikkel and Maxwell, 2007), BnLAS in B. napus (Yang et al, 2010), PeSCL7 in Poplar (Ma et al, 2010), OsGRAS23 in rice (Kai et al, 2015), and SlGRAS40 in tomato (Liu et al, 2017) were found to be involved in drought stress. In this study, the increased drought tolerance in BrLAS overexpressing plants provides novel evidence of the role of GRAS proteins in drought stress responses.…”

“…Rice OsGRAS23 is also involved in drought and oxidative stress tolerance via regulation of stress-related gene expression (Kai et al, 2015). Overexpression of the SlGRAS40 gene in tomato was also found to enhance tolerance to abiotic stress and influence auxin and gibberellin signaling (Liu et al, 2017).…”

Transcription Factor CaSBP12 Negatively Regulates Salt Stress Tolerance in Pepper (Capsicum annuum L.)

“…Salt stress on transgenic lines was done according to the modified method described by Liu et al (2017) [2]. Each plant was planted in an independent basin (same basins were used), 11 or 10 plants of wild-type and CaSBP12 transgenic lines were placed in a big pot and watered once a week to make sure the soil water in every basin was uniform and all the plants were grown in the same conditions.…”

“…Plants frequently encounter stressful environmental conditions, such as high salinity, extreme temperatures, drought, pests, and fungus infection [1]. These leading to detrimental effects on plant growth and seed germination and fruit productivity [2]. Salinity is the principal cause of crop yield loss worldwide and adversely affects plant growth and productivity [3].…”

“…The NbWRKY79 has been reported to be involved in salt stress in Nicotiana benthamiana (N. benthamiana) [3]. The SlGRAS40 and SlAREB have been reported to be involved in abiotic stress in tomato [2,13].…”