Salinity-induced glutathione synthesis in Brassica napus

Abstract

The role of S-assimilation and the biosynthesis of cysteine and glutathione were studied during the response to salt stress of wild-type and salt-tolerant transgenic Brassica napus L. (canola) plants overexpressing a vacuolar Na+/H+ antiporter. A 3-fold increase in cysteine and glutathione content was observed in wild-type plants exposed to salt stress, but not in the transgenic plants. The induction of cysteine and glutathione synthesis during salt stress in the wild-type plants suggests a possible protective mechanism against salt-induced oxidative damage. On the other hand, the salt-tolerant transgenic plants did not show significant changes in either cysteine or glutathione content, confirming the role of vacuolar Na+ accumulation and ion homeostasis in salt tolerance.

Morphological and physio-biochemical characterization ofBrassica junceaL. Czern. & Coss. genotypes under salt stress

“…ATP-sulphurylase enzyme catalyzes the first step of the sulphate assimilation which is an essential pathway for a source of reduced sulphur for various cellular processes and for the synthesis of the sulphur-containing amino acids cysteine and methionine, the important biological tripetide glutathione, a major factor in plant stress defense (Ernst 1998;Ruiz and Blumwald 2002;Kopriva and Rennenberg 2004). The present investigation reveals that salt-exposed plants of all genotypes exhibited reduced activity of ATP-S (Figure 6).…”

Glutathione in plants: biosynthesis and physiological role in environmental stress tolerance

“…Enhanced GSH level was also correlated with enhanced salt tolerance in several studies. For example, wild type canola seedlings showed a threefold increase in GSH and Cys synthesis during exposure to salt stress when compared to transgenic plants that lacked the genes for GSH and Cys synthesis; the wild type also showed greater salinity tolerance, suggesting a protective mechanism for GSH against salt stress (Ruiz and Blumwald 2002). Glutathione is also associated with the detoxification of methylyglyoxal.…”

Physiological and biochemical characterization of rootlets response to salt stress in two <i>Medicago truncatula</i> Gaertn. ecotypes

“…In the ascorbate-glutathione pathway, GSH regenerates ascorbate by reducing DHA (Dixon et al 2002). An enhance in the level of the GSH pool in the tolerant genotype Tru 131 under severe salt stress condition is generally considered as a protective response against oxidative stress (Ruiz and Blumwald 2002) and GSH is necessary for cell division in root tips (Vernoux et al 2000). Gietler et al (2016) demonstrated that the total Glutathione content increases in tolerant young seedlings of wheat (Triticum aestivum L.) to water deficit than sensitive seedlings after 6 d of germination.…”