Proteomic profiling of γ-ECSoverexpressed transgenicNicotianain response to drought stress

Abstract

The contribution of Glutathione (Gsh) in drought stress tolerance is an established fact. however, the proteins which are directly or indirectly related to the increased level of Gsh in response to drought stress are yet to be known. To explore this, here, transgenic tobacco plants (NtGp11) overexpressing gamma-glutamylcysteine synthetase (γ-ECS) was tested for tolerance against drought stress. NtGp11 conferred tolerance to drought stress by increased germination rate, water retention, water recovery, chlorophyll, and proline content compared with wild-type plants. semi-quantitative RT-PcR analysis revealed that the transcript levels of stress-responsive genes were higher in NtGp11 compared with wild-type in response to drought stress. Two-dimensional gel electrophoresis (2-De) coupled with MaLDI TOF-TOF Ms/Ms analysis has been used to identify 43 differentially expressed proteins in response to drought in wild-type and NtGp11 plants. The results demonstrated the up-accumulation of 58.1% of proteins among which 36%, 24%, and 20% of them were related to stress and defense, carbon metabolism and energy metabolism categories, respectively. Taken together, our results demonstrated that Gsh plays an important role in combating drought stress in plants by inducing stress related genes and proteins like hsP70, chalcone synthase, glutathione peroxidase, thioredoxin peroxidase, acc oxidase, and heme oxygenase I.

Membrane transporters and drought resistance – a complex issue

“…Proline accumulation is the first response of plants subjected to a range of environmental stressors, including drought. The correlation between this widely occurring amino acid and drought tolerance has been demonstrated in several plant species ( Javed et al, 2014 ; Kumar et al, 2014a ; Ravikumar et al, 2014 ; Singh et al, 2014 ). In addition to its well-established role in osmotic adjustment, Pro contributes to stress tolerance by functioning as a molecular chaperon that stabilizes subcellular structures, as a free radical scavenger and as stress-signaling molecule.…”

Glutathione as a Crucial Modulator of Phytohormone Signalling during Pathogen Defence in Plants

“…In transgenic tobacco with enhanced GSH content, up-regulation of ET related transcripts like ACO, ERF4 and WRKY1 and up-accumulation of proteins like ACC synthase (ACS) and ACO has been reported recently (Ghanta et al, 2014). These transgenic plants have also been reported to exhibit tolerance against pathogenesis as well as osmotic stress thus demonstrating the involvement of GSH-ET interplay in imparting stress tolerance in plants (Ghanta et al, 2014;Kumar et al, 2014).…”

Low-glutathione mutants are impaired in growth but do not show an increased sensitivity to moderate water deficit

“…First experiments to answer this question have provided contradicting results. Overexpression of the first and regulatory enzyme in GSH biosynthesis, GSH1, in tobacco has been reported to confer tolerance to drought stress [30]. Consistent with this an increased GSH level was reported to confer tolerance to drought and salt stress while the partially GSH-deficient mutant pad2 displays a significantly lower survival rate than wild-type plants after a two-week drought treatment [31].…”