Overexpression of Saussurea involucrata dehydrin gene SiDHN promotes cold and drought tolerance in transgenic tomato plants

Abstract

Dehydrins are late embryogenesis abundant proteins that help regulate abiotic stress responses in plants. Overexpression of the Saussurea involucrata dehydrin gene SiDHN has previously been shown to improve water-use efficiency and enhance cold and drought tolerance of transgenic tobacco. To understand the mechanism by which SiDHN exerts its protective function, we transformed the SiDHN gene into tomato plants (Solanum lycopersicum L.) and assessed their response to abiotic stress. We observed that in response to stresses, the SiDHN transgenic tomato plants had increased contents of chlorophyll a and b, carotenoid and relative water content compared with wild-type plants. They also had higher maximal photochemical efficiency of photosystem II and accumulated more proline and soluble sugar. Compared to those wild-type plants, malondialdehyde content and relative electron leakage in transgenic plants were not significantly increased, and H2O2 and O2- contents in transgenic tomato plants were significantly decreased. We further observed that the production of stress-related antioxidant enzymes, including superoxide dismutase, ascorbate peroxidase, peroxidase, and catalase, as well as pyrroline-5-carboxylate synthetase and lipid transfer protein 1, were up-regulated in the transgenic plants under cold and drought stress. Based on these observations, we conclude that overexpression of SiDHN gene can promote cold and drought tolerance of transgenic tomato plants by inhibiting cell membrane damage, protecting chloroplasts, and enhancing the reactive oxygen species scavenging capacity. The finding can be beneficial for the application of SiDHN gene in improving crop tolerance to abiotic stress and oxidative damage.

The Soybean bZIP Transcription Factor Gene GmbZIP2 Confers Drought and Salt Resistances in Transgenic Plants

“…Based on recent research, a bZIP transcription factor of sweet potato, IbbZIP37, interacted with the ABRE cis-element to cope with drought, salt and heat shock stresses [45]. In another study, the FtbZIP83 gene from Fagopyrum tataricum showed an increased adaptability to drought and salt stresses and its promoter had high activity in transgenic Arabidopsis [46], and stress responsive cis-acting elements, such as DRE, ABRE, MYB, MYC, LTR and TGACG-motif elements, were found in their promoter regions [45,46]. In our study, the same cis-acting elements were detected in the GmbZIP2 promoter.…”

“…GmWD40 encodes a WD40 structure protein that was reported to play crucial roles in diverse protein-protein interactions by acting as a scaffolding molecule and thus assisting in the proper functionality of proteins and being involved with abiotic stress response [48]. GmDHN15 is a dehydrin protein that serves a purpose in drought stress response [46]. GmLEA is a late-embryogenesis abundant protein with a major role in drought and other abiotic stresses tolerance in plants [49].…”

“…The genome and protein sequences of the 15 soybean bZIPs were downloaded from Phytozome. The online software Gene Structure Display Server (http://gsds.cbi.pku.edu.cn/) was used to analyze the structure of 15 soybean bZIP genes [46]. The protein structure of the 15 soybean bZIPs were obtained by using ExPAsy-PROSITE (http://prosite.expasy.org/).…”

Dehydrins: an overview of current approaches and advancement

“…In that paper, the increase in stress tolerance of PpDHN transgenic plants has been shown to be associated with an increase in ROS scavenging ability and maintenance of membrane integrity . In another study, SiDHN, a dehydrin member in Saussurea involucrata, a dicotyl plant resistant to harsh stress conditions, was found to significantly increase the tolerance of the transgenic tobacco plants to low temperature and drought stresses (Guo et al, 2019). Moreover, OesDHN, a DHN gene from oleaster (Oleaster europaea L.), a wild olive form and a drought-resistant plant in the Mediterranean region, has been shown to increase drought tolerance when overexpressed in Arabidopsis (Chiappetta et al, 2015).…”

Grafting Alleviates Cadmium Toxicity and Reduces Its Absorption by Tomato

“…Free proline content was determined by acid ninhydrin colorimetry; soluble protein was measured by the Coomassie brilliant blue G-250 method; and soluble sugar content was determined by the sulfuric acid-anthrone colorimetric method (Guo et al 2019).…”