Abstract
Heterotrimeric guanine nucleotide-binding proteins (G proteins) composed of alpha (Gα), beta (Gβ), and gamma (Gγ) subunits are central signal transducers mediating the cellular response to multiple stimuli, such as cold, in eukaryotes. Plant Gγ subunits, divided into A, B, and C three structurally distinct types, provide proper cellular localization and functional specificity to the heterotrimer complex. Here, we demonstrate that a type C Gγ subunit CsGG3.2 is involved in the regulation of the CBF regulon and plant tolerance to cold stresses in cucumber (Cucumis sativus L.). We showed that CsGG3.2 transcript abundance was positively induced by cold treatments. Transgenic cucumber plants (T1) constitutively over-expressing CsGG3.2 exhibits tolerance to chilling conditions and increased expression of CBF genes and their regulon. Antioxidative enzymes, i.e., superoxide dismutase, catalase, peroxidase, and glutathione reductase activities increased in cold-stressed transgenic plants. The reactive oxygen species, oxygen free radical and H2O2, production, as well as membrane lipid peroxidation (MDA) production decreased in transgenic plants, suggesting a better antioxidant system to cope the oxidative-damages caused by cold stress. These findings provide evidence for a critical role of CsGG3.2 in mediating cold signal transduction in plant cells.
Highlights
Cold stress, which includes chilling (
Genes coding CBFs (C-repeat binding factors), HSFC1, ZAT12, and CZF1 (CCCH-type zinc finger 1) are induced, and in turn regulate downstream cold responsive gene (COR) expression making changes in metabolism and physiological processes (Jia et al, 2016; Zhao et al, 2016). These include the changes in the activity of antioxidant enzymes, such as ascorbate peroxidase (APX), superoxide dismutase (SOD), and catalase (CAT), which contributes to increased freezing tolerance (Streb et al, 2002; Janda et al, 2003; Zhang et al, 2008)
DEP1 and GS3 are major quantitative trait loci for controlling seed size and panicle branching (Botella, 2012); RGG1 and RGG2 are upregulated upon salinity, harsh temperature, and ABA treatments (Yadav et al, 2012)
Summary
Cold stress, which includes chilling (
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
