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.
28 May 2014-BioMed Research International (Hindawi Publishing Corporation)-Vol. 2014, pp 479180-479180
TL;DR: Results indicated vital role of glutathione in maintaining abnormal proliferations in plant organs, and its deficiency triggered phenotypic reversal through metabolic diversions of cysteine and concomitant cellular and metabolic modulations.
Abstract: A Lathyrus sativus L. mutant isolated in ethylmethane sulfonate-treated M2 progeny of mother variety BioL-212 and designated as rlfL-1 was characterized by inwardly rolled-leaf and stem and bud fasciations. The mutant exhibited karyomorphological peculiarities in both mitosis and meiosis with origin of aneuploidy. The mitosis was vigorous with high frequency of divisional cells and their quick turnover presumably steered cell proliferations. Significant transcriptional upregulations of cysteine and glutathione synthesis and concomitant stimulations of glutathione-mediated antioxidant defense helped rlfL-1 mutant to maintain balanced reactive oxygen species (ROS) metabolisms, as deduced by ROS-imaging study. Glutathione synthesis was shut down in buthionine sulfoximine- (BSO-) treated mother plant and mutant, and leaf-rolling and stems/buds fasciations in the mutant were reversed, accompanied by normalization of mitotic cell division process. Antioxidant defense was downregulated under low glutathione-redox but cysteine-desulfurations and photorespiratory glycolate oxidase transcripts were markedly overexpressed, preventing cysteine overaccumulation but resulted in excess H2O2 in BSO-treated mutant. This led to oxidative damage in proliferating cells, manifested by severe necrosis in rolled-leaf and fasciated stems. Results indicated vital role of glutathione in maintaining abnormal proliferations in plant organs, and its deficiency triggered phenotypic reversal through metabolic diversions of cysteine and concomitant cellular and metabolic modulations.
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TL;DR: This review describes progress achieved in Lathyrus genetic improvement and explores potential opportunities and urgent research needs for this somewhat neglected crop.
Abstract: Grass pea offers an attractive choice for sustainable food production, owing to its intrinsic properties including limited water requirement and drought tolerance. However, low productivity and the presence of a neurotoxin (ODAP) have posed major obstacles to its genetic improvement. Also, biotechnological investments remain limited and the genome is complex and not well understood. Strategies that allow identification of genotypes with reduced ODAP content, coupling of low ODAP content with enhanced yield, and effective seed detoxification methods merit immediate attention. Breeder-friendly genomic tools are being increasingly made available to improve the efficiency of breeding protocols. To this end, the application of next-generation sequencing has provided a means of leveraging the repertoire of genomic resources for this somewhat neglected crop. In this review, we describe progress achieved in Lathyrus genetic improvement. We also explore potential opportunities in Lathyrus research and identify urgent research needs.
67 citations
TL;DR: It is 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.
Abstract: 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.
13 citations
Cites background from "Leaf rolling and stem fasciation in..."
...Generally, leaf rolling is largely regulated by several factors: hormones (Fujino et al. 2008; Lee et al. 2006), metabolic changes (Talukdar and Talukdar, 2014) and formation of specific cells, such as bulliform cell (Fang et al. 2012; Xiang et al. 2012)....
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04 Mar 2015
TL;DR: Investigation of the functional relationship between hydrogen sulfide (H2S) and glutathione (GSH) in regulation of sulfate transporters and cysteine metabolisms revealed dual roles of H2S as stimulator of GSH-independent antioxidant defense and regulator of cysteines homeostasis through its metabolic diversion during As-exposure and blockage of G SH biosynthesis.
Abstract: 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.
11 citations
Cites background or methods or result from "Leaf rolling and stem fasciation in..."
...In agreement with the present findings, BSO-treated rlfL-1 mutant of Lathyrus induced Cys desulfuration which played prominent roles in reversal of cell proliferations and restoration of normal mitosis during low GSH level (Talukdar and Talukdar 2014b)....
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...The result pointed out that cytosolic isoforms (Cu/Zn SODs) in both bean genotypes played pivotal roles in maintaining SOD activity during As-exposures, which confirmed earlier findings (Abercrombie et al. 2008; Talukdar and Talukdar 2013, 2014a)....
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...Mutants deficient in Cys-desulfuration pathway exhibited overaccumulation of free Cys which led to excess ROS generation and oxidative imbalance (Álvarez et al. 2010; Talukdar 2014) but relieved when Cys-desulfuration was induced (Talukdar and Talukdar 2014b)....
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...Inverse relationship between GSH pool and expressions of GO transcripts was also observed in rlfL-1 mutant of grass pea in which diminishing GSH redox due to BSO treatment led to enhanced GO expressions and photorespiratory H2O2 production (Talukdar and Talukdar 2014b)....
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...Relative gene expression analysis through quantitative RT-PCR Total RNA isolation and first-strand cDNA synthesis were done following manufacturer’s (Chromous Biotech, Bangalore, India) instructions, as detailed earlier (Talukdar and Talukdar 2014a)....
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TL;DR: Results revealed that major metabolic reshuffling is imminent in both up-stream and down-stream thiol cascade during low GSH-redox, and H2S may confer As-tolerance through stimulation of G SH-independent antioxidant defense and maintaining Cys-homeostasis in grass pea mutant.
Abstract: Coordinated response between cysteine (Cys) metabolisms as up-stream and GSH-dependent antioxidant defense as down-stream thiol cascade was investigated in two genotypes of hardy legume grass pea (Lathyrus sativus L.), namely a glutathione (GSH)-deficient mutant (gshL-1) and BioL-212 genotype under (a) 40 μM As (sodium arsenate) and (b) As +1 mM BSO (L-buthionine-sulfoximine) treatments. As-treatment alone induced biosynthesis of Cys, GSH, and phytochelatins but partially stimulated GSH-dependent antioxidant defense in the mutant. GSH S-transferase activity was elevated but activities of GSH-dependent ascorbate (AsA)-GSH cycle enzyme including GSH-reductase remained low in the As-exposed mutant. This resulted in As-induced partial growth inhibition of the mutant. At As + BSO, GSH-synthesis was totally inhibited, leading to significantly low GSH-redox pool and steep decline in GSH-dependent antioxidant capacity of both the genotypes. However, Cys-degradation pathway was induced in gshL-1 mutant, resulting in significant accumulation of endogenous H2S. This was accompanied with stimulation of AsA-dependent antioxidant defense and catalases and regulation of Cys-synthesis, preventing over-accumulation of H2O2 and free Cys, respectively. No As-induced oxidative damage and growth inhibition were observed in As + BSO-treated mutant. Contrastingly, failure to induce entire defense cascade under BSO resulted in onset of As-induced oxidative stress in BioL-212 genotype. Results revealed that major metabolic reshuffling is imminent in both up-stream and down-stream thiol cascade during low GSH-redox, and H2S may confer As-tolerance through stimulation of GSH-independent antioxidant defense and maintaining Cys-homeostasis in grass pea mutant.
5 citations
References
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225,085 citations
TL;DR: The 2-Delta Delta C(T) method as mentioned in this paper was proposed to analyze the relative changes in gene expression from real-time quantitative PCR experiments, and it has been shown to be useful in the analysis of realtime, quantitative PCR data.
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Abstract: Methods of enzymatic analysis , Methods of enzymatic analysis , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی
18,100 citations
TL;DR: Observations confirm that the electron donor for the scavenging of hydrogen peroxide in chloroplasts is L-ascorbate and that the L-ASCorbate is regenerated from DHA by the system: photosystem I-*ferredoxin-*NADP^>glutathione and a preliminary characterization of the chloroplast peroxidase is given.
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8,406 citations
"Leaf rolling and stem fasciation in..." refers methods in this paper
...APX activity was expressed as μmol ascorbate oxidized minmg protein [38]....
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