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1.
Funct Integr Genomics ; 22(2): 153-170, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34988675

RESUMO

Drought, a major abiotic limiting factor, could be modulated with in-built reprogramming of plants at molecular level by regulating the activity of plant developmental processes, stress endurance and adaptation. The transgenic Arabidopsis thaliana over-expressing metallothionein 1 (MT1) gene of desi chickpea (Cicer arietinum L.) was subjected to transcriptome analysis. We evaluated drought tolerance of 7 days old plants of Arabidopsis thaliana in both wild-type (WT) as well as transgenic plants and performed transcriptome analysis. Our analysis revealed 24,737 transcripts representing 24,594 genes out of which 5,816 were differentially expressed genes (DEGs) under drought conditions and 841 genes were common in both genotypes. A total of 1251 DEGs in WT and 2099 in MT1 were identified in comparison with control. Out of the significant DEGs, 432 and 944 were upregulated, whereas 819 and 1155 were downregulated in WT and MT1 plants, respectively. The physiological and molecular parameters involving germination assay, root length measurements under different stress treatments and quantitative expression analysis of transgenic plants in comparison to wild-type were found to be enhanced. CarMT1 plants also demonstrated modulation of various other stress-responsive genes that reprogrammed themselves for stress adaptation. Amongst various drought-responsive genes, 24 DEGs showed similar quantitative expression as obtained through RNA sequencing data. Hence, these modulatory genes could be used as a genetic tool for understanding and delineating the mechanisms for fine-tuning of stress responses in crop plants.


Assuntos
Arabidopsis , Cicer , Arabidopsis/genética , Arabidopsis/metabolismo , Cicer/genética , Cicer/metabolismo , Secas , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Metalotioneína/genética , Metalotioneína/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Estresse Fisiológico/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
2.
Funct Integr Genomics ; 22(4): 625-642, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35426545

RESUMO

To understand drought tolerance mechanism(s) in clusterbean (Cyamopsis tetragonoloba), we conducted physiological, biochemical, and de novo comparative transcriptome analysis of drought-tolerant (RGC-1002) and drought-sensitive (RGC-1066) genotypes subjected to 30 days of drought stress. Relative water content (RWC) was maintained in tolerant genotype but was reduced in sensitive genotype. Leaf pigment concentrations were higher in tolerant genotype. Net photosynthesis was significantly decreased in sensitive genotype but insignificant reduction was found in tolerant genotype. Enzymatic antioxidant (GR, APX, DHAR) activities were enhanced in tolerant genotype, while there were insignificant changes in these enzymes in sensitive genotype. The ratios of antioxidant molecules (ASC/DHA and GSH/GSSG) were higher in tolerant genotype as compared to sensitive genotype. In sensitive genotype, 6625 differentially expressed genes (DEGs) were upregulated and 5365 genes were downregulated. In tolerant genotype, 5206 genes were upregulated and 2793 genes were downregulated. In tolerant genotype, transketolase family protein, phosphoenolpyruvate carboxylase 3, temperature-induced lipocalin, and cytochrome oxidase were highly upregulated. Moreover, according to Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, the drought tolerance may be attributed to upregulated starch and sucrose metabolism-related genes in tolerant genotype. Finally, quantitative real-time PCR confirmed the reproducibility of the RNA-seq data.


Assuntos
Cyamopsis , Secas , Antioxidantes/metabolismo , Cyamopsis/genética , Cyamopsis/metabolismo , Mecanismos de Defesa , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genótipo , Reprodutibilidade dos Testes , Estresse Fisiológico/genética , Transcriptoma
3.
J Exp Bot ; 73(8): 2525-2539, 2022 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-35084469

RESUMO

The roles of cytosolic O-acetylserine-(thiol)-lyase A (OASTLA), chloroplastic OASTLB, and mitochondrial OASTLC in plant selenate resistance were studied in Arabidopsis. Impairment in OASTLA and OASTLB resulted in reduced biomass, chlorophyll and soluble protein content compared with selenate-treated OASTLC-impaired and wild-type plants. The generally lower total selenium (Se), protein-Se, organic-sulfur and protein-sulfur (S) content in oastlA and oastlB compared with wild-type and oastlC leaves indicated that Se accumulation was not the main cause for the stress symptoms in these mutants. Notably, the application of selenate positively induced S-starvation markers and the OASTLs, followed by increased sulfite reductase, sulfite oxidase activities, and increased sulfite and sulfide concentrations. Taken together, our results indicate a futile anabolic S-starvation response that resulted in lower glutathione and increased oxidative stress symptoms in oastlA and oastlB mutants. In-gel assays of l-cysteine and l-seleno-cysteine, desulfhydrase activities revealed that two of the three OASTL activity bands in each of the oastl single mutants were enhanced in response to selenate, whereas the impaired proteins exhibited a missing activity band. The absence of differently migrated activity bands in each of the three oastl mutants indicates that these OASTLs are major components of desulfhydrase activity, degrading l-cysteine and l-seleno-cysteine in Arabidopsis.


Assuntos
Arabidopsis , Liases , Selênio , Arabidopsis/metabolismo , Carbono-Oxigênio Liases/metabolismo , Cisteína/metabolismo , Liases/metabolismo , Ácido Selênico , Selênio/metabolismo , Serina/análogos & derivados , Compostos de Sulfidrila/metabolismo , Sulfitos/metabolismo , Enxofre/metabolismo
4.
Ecotoxicol Environ Saf ; 208: 111418, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33045435

RESUMO

The present study investigates the role of Chlorella sp. in the mitigation of arsenic (iAs) induced toxicity in Oryza sativa L. The study shows, co-culture of rice seedlings with Chlorella sp. reduced the iAs accumulation, simultaneously improving the growth of seedlings under iAs treatments. While treatment with As(III) and As(V) (60 µM) alone, inflicted toxicity in rice seedlings, manifested as significant enhancement in stress markers levels (TBRAS and H2O2), this coincided with the shifting of cellular reduced state to oxidized state (reduced GSH/GSSG ratio). Contrarily, co-culturing rice seedlings with Chlorella sp. under iAs toxicity, reduced these stress markers and recovered the GSH/GSSG ratio. The GSH dependent antioxidant enzymes i.e. GR and GPX activities also exhibited significant enhancement upon co-culturing rice seedlings with Chlorella sp. against iAs stress. Simultaneously, the expression of four thiol dependent GRX genes, i.e. GRX13950, GRX35340, GRX12190 and GRX07950 were enhanced against As(III) and As(V) (60 µM), which reduced upon co-culturing with Chlorella sp. A similar trend was also observed with the expression of GST genes, where the co-culture with Chlorella sp. significantly reduced the genes expression of two isoforms (GST 38600 and GST 38610). On the contrary, the expression of S-adenosylmethionine dependent methyltransferases (SAMT) gene in rice seedlings was enhanced upon co-culturing with the Chlorella sp. against iAs stress. Overall, the results demonstrate that the rice seedlings when co-culture with Chlorella sp. ameliorates iAs toxicity through GSH dependent detoxification pathway, evident from the enhanced expression of GRX, GST, SAMT genes and activity of GSH dependent antioxidant enzymes (GR and GPX) in the rice seedlings.


Assuntos
Arsênio/toxicidade , Glutationa/metabolismo , Oryza/fisiologia , S-Adenosilmetionina/metabolismo , Poluentes do Solo/toxicidade , Antioxidantes/metabolismo , Arsênio/metabolismo , Chlorella/metabolismo , Peróxido de Hidrogênio/metabolismo , Metiltransferases/metabolismo , Oryza/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Plântula/metabolismo , Poluentes do Solo/metabolismo
5.
Physiol Mol Biol Plants ; 27(5): 923-944, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-34092945

RESUMO

Glutaredoxins (Grxs) are short, cysteine-rich glutathione (GSH)-mediated oxidoreductases. In this study, a chickpea (Cicer arietinum L.) glutaredoxin [LOC101493651 (CaGrx)] gene has been selected based on screening experiments with two contrasting varieties of chickpea, PUSA-362 (drought-tolerant) and ICC-1882 (drought-sensitive) under drought and salinity. The tolerant variety showed higher CaGrx gene expression, as compared to less in the sensitive variety, under both the stresses. The CaGrx gene was then over-expressed in Arabidopsis thaliana and were exposed to drought and salinity. The over-expression of CaGrx elevated the activity of glutaredoxin, which induced antioxidant enzymes (glutathione reductase; GR, glutathione peroxidase; GPX, catalase; CAT, ascorbate peroxidase; APX, glutathione-S-transferase; GST, superoxide dismutase; SOD, monodehydroascorbate reductase; MDHAR, and dehydroascorbate reductase; DHAR), antioxidants (GSH and ascorbate) and stress-responsive amino acids (cysteine and proline). Enhancement in the antioxidant defense system possibly administered tolerance in transgenics against both stresses. CaGrx reduced stress markers (H2O2, TBARS, and electrolyte leakage) and enhanced root growth, seed germination, and survival against both stresses. The physiological parameters (net photosynthesis; P N, water use efficiency; WUE, stomatal conductance; g s, transpiration; E, electron transport rate; ETR, and photochemical quenching; qP), chlorophylls and carotenoids, were improved in the transgenics during both stresses, that maintained the photosynthetic apparatus and protected the plants from damage. The enhanced activity of the cysteine biosynthesis enzyme, o-acetylserine (thiol) lyase (OAS-TL), increased the cysteine level in the transgenics, which elevated glutathione biosynthesis to maintain the ascorbate-glutathione cycle under both stresses. This investigation verified that the CaGrx gene provides tolerance against salinity and drought, maintaining physiological and morphological performances, and could be exploited for genetic engineering approaches to overcome both the stresses in various crops. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12298-021-00999-z.

6.
Physiol Mol Biol Plants ; 27(12): 2665-2678, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35035129

RESUMO

Heavy metals are ubiquitously present in nature, including soil, water, and thus in plants, thereby causing a potential health risk. This study has investigated the role and efficiency of the chickpea metallothionein 1 (MT1) gene against the major toxic heavy metals, i.e., As [As(III) and As(V)], Cr(VI), and Cd toxicity. MT1 over-expressing transgenic lines had reduced As(V) and Cr(VI) accumulation, whereas Cd accumulation was enhanced in the L3 line. The physiological responses (WUE, A, Gs, E, ETR, and qP) were noted to be enhanced in transgenic plants, whereas qN was decreased. Similarly, the antioxidant molecules and enzymatic activities (GSH/GSSG, Asc/DHA, APX, GPX, and GRX) were higher in the transgenic plants. The activity of antioxidant enzymes, i.e., SOD, APX, GPX, and POD, were highest in the Cd-treated lines, whereas higher CAT activity was observed in As(V)-L1 and GRX in Cr-L3 line. The stress markers TBARS, H2O2, and electrolyte leakage were lower in transgenic lines in comparison to WT, while RWC was enhanced in the transgenic lines, and the transcript of MT1 gene was accumulated in the transgenic lines. Similarly, the level of stress-responsive amino acid cysteine was higher in transgenic plants as compared to WT plants. Among all the heavy metals, MT1 over-expressing lines showed a highly increased accumulation of Cd, whereas a non-significant effect was observed with As(III) treatment. Overall, the results demonstrate that Arabidopsis thaliana transformed with the MT1 gene mitigates heavy metal stress by regulating the defense mechanisms in plants. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12298-021-01103-1.

7.
Ecotoxicol Environ Saf ; 200: 110721, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32464438

RESUMO

Glutaredoxins (Grxs) are small (10-15 kDa) glutathione (GSH) - dependent redox proteins. The role of Grxs are well documented in tolerance to heavy metal stress in prokaryotic and mammalian systems and a few plant genera, but is poorly understood in plants against drought. In the present study, two rice glutaredoxin (Osgrx) genes (LOC_Os02g40500 and LOC_Os01g27140) responsible for tolerance against heavy metal stress have been studied for investigating their role against drought. Each glutaredoxin gene was over-expressed in Arabidopsis thaliana to reveal their role in drought stress. The relative expression of both Osgrx genes was higher in the transgenic lines. Transgenic lines of both Osgrxs showed longer roots, higher seed germination, and survival efficiency during drought stress. The physiological parameters (PN, gs, E, WUE, qP, NPQ and ETR), antioxidant enzymes (GRX, GR, GPX, GST, APX, POD, SOD, CAT, DHAR, and MDHAR), antioxidant molecules (ascorbate and GSH) and stress-responsive amino acids (cysteine and proline) levels were additionally increased in transgenic lines of both Osgrxs to provide drought tolerance. The outcomes from this study strongly determined that each Osgrx gene participated in the moderation of drought and might be utilized in biological engineering strategies to overcome drought conditions in different crops.


Assuntos
Glutarredoxinas/genética , Oryza/enzimologia , Estresse Fisiológico , Antioxidantes/metabolismo , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Ácido Ascórbico/metabolismo , Cisteína/metabolismo , Secas , Genes de Plantas , Glutarredoxinas/metabolismo , Glutationa/metabolismo , Oryza/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Prolina/metabolismo , Estresse Fisiológico/genética
8.
Ecotoxicol Environ Saf ; 192: 110252, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32014725

RESUMO

Glutaredoxins (Grxs) are small multifunctional redox proteins. Grxs have glutathione-dependent oxidoreductase activity in the presence of glutathione reductase and NADPH. The role of Grxs is well studied in heavy metal tolerance in prokaryotic and mammalian systems but not in plant genera. In the present study, a chickpea glutaredoxin (CaGrx) gene (LOC101493651) has been investigated against metal stress based on its primary screening in chickpea which revealed higher up-regulation of CaGrx gene under various heavy metals (AsIII-25 µM, AsV-250 µM, Cr(VI)-300 µM, and Cd-500 µM) stress. This CaGrx gene was overexpressed in Arabidopsis thaliana and investigated various biochemical and physiological performances under each metal stress. Transgenic plants showed significant up-regulation of the CaGrx gene during qRT-PCR analysis as well as longer roots, higher seed germination, and survival efficiency during each metal stress. The levels of stress markers, TBARS, H2O2, and electrolyte leakage were found to be less in transgenic lines as compared to WT revealed less toxicity in transgenics. The total accumulation of AsIII, AsV, and Cr(VI) were significantly reduced in all transgenic lines except Cd, which was slightly reduced. The physiological parameters such as net photosynthetic rate (PN), stomatal conductance (gs), transpiration (E), water use efficiency (WUE), photochemical quenching (qP), and electron transport rate (ETR), were maintained in transgenic lines during metal stress. Various antioxidant enzymes such as glutaredoxin (GRX), glutathione reductase (GR), glutathione peroxidase (GPX), glutathione-S-transferase (GST), ascorbate peroxidase (APX), superoxide dismutase (SOD), catalase (CAT), dehydroascorbate reductase (DHAR), monodehydroascorbate reductase (MDHAR), antioxidant molecules (ascorbate, GSH) and stress-responsive amino acids (proline and cysteine) levels were significantly increased in transgenic lines which provide metal tolerance. The outcome of this study strongly indicates that the CaGrx gene participates in the moderation of metal stress in Arabidopsis, which can be utilized in biotechnological interventions to overcome heavy metal stress conditions in different crops.


Assuntos
Antioxidantes/metabolismo , Cicer/enzimologia , Glutarredoxinas/metabolismo , Metais Pesados/toxicidade , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Arabidopsis/metabolismo , Arabidopsis/fisiologia , Ascorbato Peroxidases/metabolismo , Catalase/metabolismo , Glutarredoxinas/genética , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Glutationa Redutase/metabolismo , Estresse Oxidativo , Oxirredutases/metabolismo , Superóxido Dismutase/metabolismo
9.
Ecotoxicol Environ Saf ; 173: 15-27, 2019 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-30743076

RESUMO

γ-aminobutyric acid (GABA) is a free amino acid, which helps to counteract biotic and abiotic stresses in plants. In the present study, two concentrations of GABA, i.e., 0.5 mM and 1 mM were applied to examine the tolerance of rice seedlings against As(III) (25 µM) toxicity, through the modulations of fatty acids (FAs), stress responsive amino acids (AAs) and polyamines (PAs) biosynthesis. Exogenous GABA (0.5 mM) application significantly reduced the H2O2 and TBARS levels and recovered the growth parameters against As(III) stressed rice seedlings. Simultaneously, co-application of GABA (0.5 and 1 mM) and As(III), consistently enhanced the level of unsaturated fatty acids (USFA) (cis-10-pentadecanoic acid, oleic acid, α-linolenic acid and γ-linolenic acid), which was higher than saturated fatty acid (SFA). Among the USFAs, level of linolenic acid was found to be always higher with GABA application. Similarly, elevated level of AAs (proline, methionine, glutamic acid and cysteine) was also observed with the application of GABA (0.5 and 1 mM) in As(III) stressed seedlings. GABA also enhanced the expression of genes involved in the polyamine synthesis pathway namely arginine decarboxylase (AD), spermine (SPM) and spermidine (SPD) synthase against As(III) treatments, which was higher in roots than in shoots, resulting in enhanced root PAs level. Contrarily, the expression of S-adenosylmethionine decarboxylase (S-AMD) was significantly higher in shoots. Among all the PAs, level of putrescine (PUT) was found to be highest with GABA application. Overall, the study demonstrates that GABA (0.5 mM) at lower concentration plays a vital role in As(III) tolerance by enhancing the biosynthesis of USFA, AA and PA, reducing the level of TBARS and H2O2 in rice seedlings.


Assuntos
Aminoácidos/metabolismo , Arsenitos/toxicidade , Ácidos Graxos/metabolismo , GABAérgicos/farmacologia , Oryza/efeitos dos fármacos , Poliaminas/metabolismo , Vias Biossintéticas/genética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Oryza/crescimento & desenvolvimento , Oryza/metabolismo , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Ácido gama-Aminobutírico/farmacologia
10.
Ecotoxicol Environ Saf ; 171: 54-65, 2019 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-30597317

RESUMO

Drought is one of the major abiotic stresses which negatively affect plant growth and crop yield. Metallothionein (MTs) is a low molecular weight protein, mainly involved in metal homeostasis, while, its role in drought stress is still to be largely explored. The present study was aimed to investigate the role of MT gene against drought stress. The chickpea MT based on its up-regulation under drought stress was overexpressed in Arabidopsis thaliana to explore its role in mitigation of drought stress. The total transcript of MT gene was up to 30 fold higher in transgenic lines. Arabidopsis plants transformed with MT gene showed longer roots, better efficiency of survival and germination, larger siliques and higher biomass compared to WT. The physiological variables (A, WUE, G, E, qP and ETR) of WT plants were reduced during drought stress which recovered in transgenic Arabidopsis lines. The enzymatic and non-enzymatic antioxidant (APX, GPX, POD, GR, GRX, GST, CAT, MDHAR, ASc and GSH) levels were also enhanced in transgenic lines to provide tolerance. Simultaneously, drought responsive amino acids, i.e. proline and cysteine contents were higher in transgenic lines. Overall, the results suggest that MT gene is actively involved in the mitigation of drought stress and could be the choice for genetic engineering strategy to overcome drought stress.


Assuntos
Adaptação Fisiológica/genética , Antioxidantes/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Metalotioneína/genética , Metalotioneína/metabolismo , Estresse Fisiológico , Adaptação Fisiológica/fisiologia , Cicer/genética , Cisteína/metabolismo , Secas , Regulação da Expressão Gênica de Plantas , Germinação , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Prolina/metabolismo
11.
Ecotoxicol Environ Saf ; 151: 109-117, 2018 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-29331724

RESUMO

The present study was intended to investigate the role of algae, Anabaena sp. in the amelioration of As toxicity, when co-cultured with rice seedlings. The reduction of growth in rice seedlings against As(III) and As(V) was recovered with Anabaena sp. The Anabaena sp. also reduced the accumulation of As, where it was more efficient against 60µM As(III) (49%) than As(V) (23%) in rice shoot. Similarly, with reduction of As accumulation, lower silicon transporters (Lsi-1 and Lsi-2) was found to be suppressed against As treatments. However, the expression of two nitrogen dependent genes i.e., NR and SAMT were found to be enhanced with the Anabaena sp. Likewise, the activity of antioxidant enzyme, GST, was enhanced, whereas, the activity of other enzymes such as SOD, APX, GPX, GR and DHAR were decreased with As+Algae combinations. Overall, the result suggested that the Anabaena sp. reduces As accumulation, modulates gene expressions and antioxidants to ameliorate the As toxicity in Oryza sativa L.


Assuntos
Anabaena/fisiologia , Arsênio/metabolismo , Arsênio/toxicidade , Oryza/efeitos dos fármacos , Oryza/metabolismo , Antioxidantes/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Membrana Transportadoras/metabolismo , Nitrogênio/metabolismo , Oryza/genética , Oryza/crescimento & desenvolvimento , Plântula/efeitos dos fármacos , Plântula/metabolismo , Silício/metabolismo
12.
Ecotoxicol Environ Saf ; 148: 410-417, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29101885

RESUMO

The present study was intended to investigate the role of amino acid glycine in detoxification of As in Oryza sativa L. The growth parameters such as, shoot length and fresh weight were decreased during As(III) and As(V) toxicity. However, the application of glycine recovered the growth parameters against As stress. The application of glycine reduced the As accumulation in all the treatments, and it was more effective against As(III) treatment and reduced the accumulation by 68% in root and 71% in shoot. Similarly, the translocation of As from root to shoot, was higher against As(III) and As(V) treatments, whereas, reduced upon glycine application. The translocation of Fe and Na was also affected by As, which was lower under As(III) and As(V) treatments. However, the application of glycine significantly enhanced the translocation of Fe and Na in the shoot. Besides, the expression of lower silicon transporters i.e. Lsi-1 and Lsi-2 was observed to be significantly suppressed in the root with the application of glycine against As treatment. Similarly, the expression of three GRX and two GST gene isoforms were found to be significantly increased with glycine application. Simultaneously, the activities of antioxidant enzymes i.e. l-arginine dependent NOS, SOD, NTR and GRX were found to be significantly enhanced in the presence of glycine. Increased activities of antioxidant enzymes coincided with the decreased level of TBARS and H2O2 in rice seedlings. Overall, the results suggested that the application of glycine reduces As accumulation through suppressing the gene expression of lower silicon transporters and ameliorates As toxicity by enhancing antioxidants defense mechanism in rice seedlings.


Assuntos
Arsênio/toxicidade , Glicina/farmacologia , Proteínas de Membrana Transportadoras/genética , Oryza/efeitos dos fármacos , Silício/metabolismo , Antioxidantes/metabolismo , Arsênio/farmacocinética , Regulação da Expressão Gênica , Proteínas de Membrana Transportadoras/metabolismo , Oryza/genética , Oryza/metabolismo , Raízes de Plantas/metabolismo , Plântula/metabolismo
13.
Ecotoxicol Environ Saf ; 124: 393-405, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26606179

RESUMO

Embodied study investigates the role of GRX and associated antioxidant enzymes in the detoxification mechanism between arsenic (As) sensitive (Usar-3) and tolerant cultivar (Pant Dhan 11) of Oryza sativa against As(III) and As(V), under GSH enriched, and GSH deprived conditions. The overall growth and physiological parameters in sensitive cultivar were lower than the tolerant cultivar, against various treatments of As(III) and As(V). The As accumulation in sensitive cv. against both As(III) and As(V) was lower than the corresponding treatments in tolerant cv. However, the As translocation against As(V) was lower (35% and 64%, resp.) than that of As(III), in both the cultivars. In sensitive cv. translocation of Zn and Cu was influenced by both As(V) and As(III) whereas, in tolerant cv. the translocation of Cu, Mn and Zn was influenced only by As(III). Translocation of Fe was negatively influenced by translocation of As in sensitive cv. and positively in tolerant cv. Strong correlation between H2O2, SOD, GRX, GR, GST and GSH/GSSG in sensitive cv. and between DHAR, APX, MDHAR and AsA in tolerant cv. demonstrates the underlying preference of GSH as electron donor for detoxification of H2O2 in sensitive cv. and AsA in tolerant cv. Higher expression of the four GRX and two GST genes in the sensitive cv. than tolerant cv, suggests that under As stress, GRX are synthesized more in the sensitive cv. than tolerant cv. Also, the expression of four GRX genes were higher against As(V) than As(III). The higher As accumulation in the tolerant cv. is due to lower GST expression, is attributed to the absence of thiolation and sequestration of As in roots, the translocation of As to shoots is higher.


Assuntos
Antioxidantes/metabolismo , Arsênio/toxicidade , Glutarredoxinas/metabolismo , Glutationa Transferase/metabolismo , Oryza/efeitos dos fármacos , Arsênio/metabolismo , Glutarredoxinas/genética , Glutationa/administração & dosagem , Glutationa Transferase/genética , Peróxido de Hidrogênio/metabolismo , Oryza/enzimologia , Oryza/crescimento & desenvolvimento , Estresse Oxidativo , Raízes de Plantas/metabolismo , Plântula/metabolismo
14.
Physiol Mol Biol Plants ; 20(4): 435-47, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25320467

RESUMO

The study investigated the reduction in metalloid uptake at equimolar concentrations (~53.3 µM) of As(III) and As(V) in contrasting pair of rice seedlings by pretreating with H2O2 (1.0 µM) and SA (1.0 mM). Results obtained from the contrasting pair (arsenic tolerant vs. sensitive) of rice seedlings (cv. Pant Dhan 11 and MTU 7029, respectively) shows that pretreatment of H2O2 and H2O2 + SA reduces As(V) uptake significantly in both the cultivars, while no reduction in the As(III) uptake. The higher growth inhibition, higher H2O2 and TBARS content in sensitive cultivar against As(III) and As(V) treatments along with higher As accumulation (~1.2 mg g(-1) dw) than in cv. P11, unravels the fundamental difference in the response between the sensitive and tolerant cultivar. In the H2O2 pretreated plants, the translocation of As increased in tolerant cultivar against AsIII, whereas, it decreased in sensitive cultivar both against AsIII and AsV. In both the cultivars translocation of Mn increased in the H2O2 pretreated plants against As(III), whereas, the translocation of Cu increased against As(V). In tolerant cultivar the translocation of Fe increased against As(V) with H2O2 pretreatment whereas, it decreased in the sensitive cultivar. In both the cultivars, Zn translocation increased against As(III) and decreased against As(V). The higher level of H2O2 and SOD (EC 1.15.1.1) activity in sensitive cultivar whereas, higher, APX (EC 1.11.1.11), GR (EC 1.6.4.2) and GST (EC 1.6.4.2) activity in tolerant cultivar, also demonstrated the differential anti-oxidative defence responses between the contrasting rice cultivars.

15.
Noncoding RNA ; 10(1)2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38392968

RESUMO

Plant species utilize a variety of regulatory mechanisms to ensure sustainable productivity. Within this intricate framework, numerous non-coding RNAs (ncRNAs) play a crucial regulatory role in plant biology, surpassing the essential functions of RNA molecules as messengers, ribosomal, and transfer RNAs. ncRNAs represent an emerging class of regulators, operating directly in the form of small interfering RNAs (siRNAs), microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs). These ncRNAs exert control at various levels, including transcription, post-transcription, translation, and epigenetic. Furthermore, they interact with each other, contributing to a variety of biological processes and mechanisms associated with stress resilience. This review primarily concentrates on the recent advancements in plant ncRNAs, delineating their functions in growth and development across various organs such as root, leaf, seed/endosperm, and seed nutrient development. Additionally, this review broadens its scope by examining the role of ncRNAs in response to environmental stresses such as drought, salt, flood, heat, and cold in plants. This compilation offers updated information and insights to guide the characterization of the potential functions of ncRNAs in plant growth, development, and stress resilience in future research.

16.
Emerg Med Int ; 2024: 6631990, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38655008

RESUMO

Knowledge about biological rhythms of diseases may not only help in understanding the pathophysiology of diseases but can also help health service policy makers and emergency department directors to allocate resources efficiently. Aneurysmal subarachnoid haemorrhage (SAH) has high rates of morbidity and mortality. The incidence of SAH has been attributed to patient-related factors such as characteristics of aneurysms, smoking, and hypertension. There are studies showing that the incidence of aneurysmal SAH appears to behave in periodic fashions over long time periods. However, there are inconsistencies in the literature regarding the impact of chronobiological factors such as circadian, seasonal, and lunar cycle factors on the occurrence of SAH. In this study, we focused on the analysis of a temporal pattern of SAH (infradian rhythms) with a novel approach using circular statistical methods. We aimed to see whether there is a circular pattern for the occurrence of SAH at all and if so, whether it can be related to known temporal patterns based on available literature. Our study did not support the notion that aneurysmal subarachnoid haemorrhages occur on any specific day in a cycle with specific lengths up to 365 days including specific weekdays, full moon, equinoxes, and solstices. Hence, we found no relationship between SAH incidence and timing. Study in larger populations using similar circular statistical methods is suggested.

17.
Front Plant Sci ; 13: 847268, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35350300

RESUMO

Exploiting consistent differences in radiation and average air temperature between two experimental vineyards (Ramat Negev, RN and Mitzpe Ramon, MR), we examined the impact of climate variations on total carotenoids, redox status, and phenylpropanoid metabolism in the berries of 10 white wine grapevine (Vitis vinifera) cultivars across three consecutive seasons (2017-2019). The differences in carotenoid and phenylpropanoid contents between sites were seasonal and varietal dependent. However, the warmer RN site was generally associated with higher H2O2 levels and carotenoid degradation, and lower flavonol contents than the cooler MR site. Enhanced carotenoid degradation was positively correlated with radiation and daily degree days, leading to a greater drop in content from véraison to harvest in Colombard, Sauvignon Blanc, and Semillon berries. Analyses of berry H2O2 and phenylpropanoids suggested differences between cultivars in the links between H2O2 and flavonol contents. Generally, however, grapes with higher H2O2 content seem to have lower flavonol contents. Correlative network analyses revealed that phenylpropanoids at the warmer RN site are tightly linked to the radiation and temperature regimes during fruit ripening, indicating potentially harmful effect of warmer climates on berry quality. Specifically, flavan-3-ols were negatively correlated with radiation at RN. Principal component analysis showed that Muscat Blanc, Riesling, Semillon, and Sauvignon Blanc were the most site sensitive cultivars. Our results suggest that grapevine biodiversity is likely the key to withstand global warming hazards.

18.
Australas Emerg Care ; 25(3): 267-272, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35125318

RESUMO

BACKGROUND: Delays in treatment of aSAH appear to be common but the causes are not well understood. We explored facilitators and barriers to timely treatment of aSAH. METHODS: We used a multiple case study with cases of aSAH surviving> 1 day identified prospectively. We conducted semi-structured interviews with the patient, their next-of-kin and health professionals involved in the case. Within-case analysis identified barriers and facilitators in 4 phases (pre-hospital, presentation, transfer, in-hospital) followed by thematic analysis across cases using a case-study matrix. RESULTS: Twenty-seven cases with 90 interviewees yielded five themes related to facilitators or barriers of timely treatment. "Early recognition" led to urgent response. "Accessibility to health care" depended on patient's location, transport, and environmental conditions. Good "Coordination" between and within health services was a key facilitator. "Complexity" of patient's condition affected time to treatment in multiple time periods. "Availability of resources" was identified most frequently during the diagnostic and treatment phases as both barrier and facilitator. CONCLUSIONS: The identified themes may be modifiable at the patient/health professional level and health system level and may improve timely treatment of aSAH through targeted interventions, subsequently contributing to improve morbidity and mortality of patients with aSAH.


Assuntos
Hemorragia Subaracnóidea , Austrália , Pessoal de Saúde , Humanos , Pesquisa Qualitativa , Hemorragia Subaracnóidea/terapia , Centros de Atenção Terciária
19.
Front Plant Sci ; 12: 690830, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34249061

RESUMO

Molybdenum cofactor containing sulfite oxidase (SO) enzyme is an important player in protecting plants against exogenous toxic sulfite. It was also demonstrated that SO activity is essential to cope with rising dark-induced endogenous sulfite levels and maintain optimal carbon and sulfur metabolism in tomato plants exposed to extended dark stress. The response of SO and sulfite reductase to direct exposure of low and high levels of sulfate and carbon was rarely shown. By employing Arabidopsis wild-type, sulfite reductase, and SO-modulated plants supplied with excess or limited carbon or sulfur supply, the current study demonstrates the important role of SO in carbon and sulfur metabolism. Application of low and excess sucrose, or sulfate levels, led to lower biomass accumulation rates, followed by enhanced sulfite accumulation in SO impaired mutant compared with wild-type. SO-impairment resulted in the channeling of sulfite to the sulfate reduction pathway, resulting in an overflow of organic S accumulation. In addition, sulfite enhancement was followed by oxidative stress contributing as well to the lower biomass accumulation in SO-modulated plants. These results indicate that the role of SO is not limited to protection against elevated sulfite toxicity but to maintaining optimal carbon and sulfur metabolism in Arabidopsis plants.

20.
J Neurol Sci ; 428: 117613, 2021 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-34418669

RESUMO

BACKGROUND: There is limited research on the provision of evidence-based care and its association with outcomes after aneurysmal subarachnoid hemorrhage (aSAH). AIMS: We examined adherence to evidence-based care after aSAH and associations with survival and discharge destination. Also, factors associated with evidence-based care including age, sex, Charlson comorbidity index, severity scores, and delayed cerebral ischemia and infarction were examined for association with survival and discharge destination. METHODS: In a retrospective cohort (2010-2016) of all aSAH cases across two comprehensive cerebrovascular centres, we extracted 3 indicators of evidence-based aSAH care from medical records: (1) antihypertensives prior to aneurysm treatment, (2) nimodipine, and (3) aneurysm treatment (coiling/clipping). We defined 'optimal care' as receiving all eligible processes of care. Survival at 1 year was obtained by data linkage. We estimated (1) proportion of patients and characteristics associated with receiving processes of care, (2) associations between processes of care with 1-year mortality using cox-proportional hazard model and discharge destination with log binomial regression adjusting for age, sex, severity of aSAH, delayed cerebral ischemia and/or cerebral infarction and comorbidities. Sensitivity analyses explored effect modification of the association between processes of care and outcome by management type (active versus comfort measures). RESULTS: Among 549 patients (69% women), 59% were managed according to the guidelines. Individual indicators were associated with lower 1-year mortality but not discharge destination. Optimal care reduced mortality at 1 year in univariable (HR 0.24 95% CI 0.17-0.35) and multivariable analyses (HR 0.51 95% CI 0.34-0.77) independent of age, sex, severity, comorbidities, and hospital network. CONCLUSION: Adherence to processes of care reduced 1-year mortality after aSAH. Many patients with aSAH do not receive evidence-based care and this must be addressed to improve outcomes.


Assuntos
Isquemia Encefálica , Aneurisma Intracraniano , Hemorragia Subaracnóidea , Isquemia Encefálica/complicações , Isquemia Encefálica/tratamento farmacológico , Estudos de Coortes , Feminino , Humanos , Masculino , Estudos Retrospectivos , Hemorragia Subaracnóidea/complicações , Hemorragia Subaracnóidea/terapia
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