Leaf rolling and stem fasciation in grass pea (Lathyrus sativus L.) mutant are mediated through glutathione-dependent cellular and metabolic changes and associated with a metabolic diversion through cysteine during phenotypic reversal

Constitutive expression of REL1 confers the rice response to drought stress and abscisic acid

Leaf rolling is one of the most significant symptoms of drought stress in plant. Previously, we identified a dominant negative mutant, termed rolled and erect 1 (hereafter referred to rel1-D), regulating leaf rolling and erectness in rice. However, the role of REL1 in drought response is still poorly understood. Here, our results indicated that rel1-D displayed higher tolerance to drought relative to wild type, and the activity of superoxide dismutase (SOD) and drought responsive genes were significantly up-regulated in rel1-D. Moreover, our results revealed that rel1-D was hypersensitive to ABA and the expression of ABA associated genes was significantly increased in rel1-D, suggesting that REL1 likely coordinates ABA to regulate drought response. Using the RNA-seq approach, we identified a large group of differentially expressed genes that regulate stimuli and stresses response. Consistently, we also found that constitutive expression of REL1 alters the expression of biotic and abiotic stress responsive genes by the isobaric tags for relative and absolute quantification (iTRAQ) analysis. Integrative analysis demonstrated that 8 genes/proteins identified by both RNA-seq and iTRAQ would be the potential targets in term of the REL1-mediated leaf morphology. Together, we proposed that leaf rolling and drought tolerance of rel1-D under normal condition might be caused by the endogenously perturbed homeostasis derived from continuous stressful dynamics.

Retracted: Leaf Rolling and Stem Fasciation in Grass Pea (Lathyrus sativus L.) Mutant Are Mediated through Glutathione-Dependent Cellular and Metabolic Changes and Associated with a Metabolic Diversion through Cysteine during Phenotypic Reversal

[This retracts the article DOI: 10.1155/2014/479180.].

Functional interplay between glutathione and hydrogen sulfide in regulation of thiol cascade during arsenate tolerance of common bean (Phaseolus vulgaris L.) genotypes

Changes in expressions of up- and downstream thiol cascade were studied in leaves of Phaseolus vulgaris L. cv. VL-63 and its mutant, pvsod1 (deficient in superoxide dismutase activity) under 50 μM sodium arsenate (As), As + L-buthionine-sulfoximine (BSO) and As + BSO + Sodium hydrosulfide (NaHS)-treatments for 10 days. Main objective was to investigate the functional relationship between hydrogen sulfide (H₂S) and glutathione (GSH) in regulation of sulfate transporters and cysteine metabolisms as up-stream thiol components and GSH, phytochelatins (PCs) and antioxidant defense response as downstream cascade under As-exposure. As treatment alone initiated coordinated inductions of sulfate transport, biosynthesis of cysteine, GSH, and PCs, and GSH-mediated antioxidant defense in the pvsod1 mutant. At As + BSO, GSH synthesis was blocked, resulting in significantly low GSH redox pool and steep decline in GSH-dependent antioxidant capacity of both the genotypes. However, unlike VL-63, cysteine-degradation pathway was induced in pvsod1 mutant, resulting in significant accumulation of endogenous H₂S. The H₂S-surge in the pvsod1 mutant stimulated ascorbate-dependent antioxidant defense and catalases and regulated O-acetylserine (thiol)lyase activity, preventing overaccumulation of H₂O₂ and free cysteine, respectively. No As-induced oxidative stress symptom was observed in the mutant. This trend was maintained at As + BSO + NaHS treatment, also. In contrast, failure to induce entire cascade from sulfate transport to downstream antioxidant defense led to onset of As-induced oxidative damage in VL-63 plant. Results revealed dual roles of H₂S as (a) stimulator of GSH-independent antioxidant defense and (b) regulator of cysteine homeostasis through its metabolic diversion during As-exposure and blockage of GSH biosynthesis.