A phenomics approach to the analysis of the influence of glutathione on leaf area and abiotic stress tolerance in Arabidopsis thaliana

Abstract

Reduced glutathione (GSH) is an abundant low molecular weight plant thiol. It fulfills multiple functions in plant biology, many of which remain poorly characterized. A phenomics approach was therefore used to investigate the effects of glutathione homeostasis on growth and stress tolerance in Arabidopsis thaliana. Rosette leaf area was compared in mutants that are either defective in GSH synthesis (cad2, pad2, and rax1) or the export of γ-glutamylcysteine and GSH from the chloroplast (clt) and in wild-type plants under standard growth conditions and following exposure to a range of abiotic stress treatments, including oxidative stress, water stress, and high salt. In the absence of stress, the GSH synthesis mutants had a significantly lower leaf area than the wild type. Conversely, the clt mutant has a greater leaf area and a significantly reduced lateral root density than the wild type. These findings demonstrate that cellular glutathione homeostasis exerts an influence on root architecture and on rosette area. An impaired capacity to synthesize GSH or a specific depletion of the cytosolic GSH pool did not adversely affect leaf area in plants exposed to short-term abiotic stress. However, the negative effects of long-term exposure to oxidative stress and high salt on leaf area were less marked in the GSH synthesis mutants than the wild type. These findings demonstrate the importance of cellular glutathione homeostasis in the regulation of plant growth under optimal and stress conditions.

Effects of Combined Low Glutathione with Mild Oxidative and Low Phosphorus Stress on the Metabolism of Arabidopsis thaliana

“…The fresh weight of the aerial parts of the mutants grown under control- and P-lim conditions was approximately 70% of that of the WT plants. These findings suggest that, under the no-stress condition, the GSH1 mutations were silent at the aerial parts, although the mutants were shown to have impaired lateral root density ( Schnaubelt et al, 2013 , 2015 ). Therefore, since the applied stress treatments did not result in severe growth inhibition in the assayed plants, we considered them as mild stress treatments ( Figures 1A,B and Supplementary Figure S2 ).…”

“…Low glutathione levels do not largely affect the shoot phenotypes of glutathione synthesis mutants under no-stress conditions. The characterization of leaf area phenotypes by using a high-resolution phenomic approach showed that glutathione synthesis mutants, except for an allele of GSH1 mutant called regulator of APX2 1-1 ( rax1-1 ) ( Ball et al, 2004 ), were not as sensitive as the WT plants under 1 μM MV treatment ( Schnaubelt et al, 2013 ). We found that the two GSH1 mutants ( cad2-1 and pad2-1 ), GSH1 -overexpressing plants [7-5 and 13-6 ( Cheng et al, 2015 )], and WT plants exhibited a similar level of growth reduction under the mild MV stress condition ( Figure 1 and Supplementary Figure S4 ).…”

Comprehensive analysis of regulatory elements of the promoters of rice sulfate transporter gene family and functional characterization ofOsSul1;1promoter under different metal stress

“…[19][20][21][22][23][24] Apart from heavy metals, the role of GSH has also been well documented in providing resistance against other abiotic stresses. 25,26 These processes require efficient sulfur uptake and homeostasis in plants which is dependent on multigene family encoding sulfate transporters. 27 Comparative transcriptome analyses of arsenate [As(V)] and arsenite [As(III)] stress in rice seedlings demonstrated differential expression of sulfate-metabolizing proteins and transporters including sulfate transporter.…”

Morphological Responses and Gene Expression of Grain Amaranth (Amaranthus spp.) Growing under Cd

“…Glutamate cysteine ligase (GCL) is a key enzyme involved in glutathione biosynthesis and is encoded by the GSH1 gene [63]. GCL is an essential component of the plant defence system in the detoxification of reactive oxygen species [64,65]. For instance, Arabidopsis plants with an identified mutation in the gene encoding the GCL enzyme showed higher susceptibility to biotic stress [66].…”