Differential response of oxidative stress and thiol metabolism in contrasting rice genotypes for arsenic tolerance.
The mechanism of arsenic (As) tolerance was investigated on two contrasting rice (Oryza sativa L.) genotypes, selected for As tolerance and accumulation. One tolerant (Triguna) and one sensitive (IET-4786) variety were exposed to various arsenate (0-50 μM) levels for 7 d for biochemical analyses. Arsenic induced oxidative stress was more pronounced in IET-4786 than Triguna especially in terms of reactive oxygen species, lipid peroxidation, EC and pro-oxidant enzymes (NADPH oxidase and ascorbate oxidase). However, Triguna tolerated As stress through the enhanced enzymes activities particularly pertaining to thiol metabolism such as serine acetyl transferase (SAT), cysteine synthase (CS), γ-glutamyl cysteine synthase (γ-ECS), γ-glutamyl transpeptidase (γ-GT), and glutathione-S-transferase (GST) as well as arsenate reductase (AR). Besides maintaining the ratio of redox couples GSH/GSSG and ASC/DHA, the level of phytochelatins (PCs) and phytochelatin synthase (PCS) activity were more pronounced in Triguna, in which harmonized responses of thiol metabolism was responsible for As tolerance in contrast to IET-4786 showing its susceptible nature towards As exposure.
C.S.I.R. -National Botanical Research Institute, Council of Scientific and Industrial Research, Lucknow 226001, India; Department of Environmental Sciences, Babasaheb Bhimrao Ambedkar (Central) University, Rae bareily Road, Lucknow-226025, India.
Preeti
P
Tripathi
C.S.I.R. -National Botanical Research Institute, Council of Scientific and Industrial Research, Lucknow 226001, India.
Aradhana
A
Mishra
C.S.I.R. -National Botanical Research Institute, Council of Scientific and Industrial Research, Lucknow 226001, India.
Sanjay
S
Dwivedi
C.S.I.R. -National Botanical Research Institute, Council of Scientific and Industrial Research, Lucknow 226001, India.
Debasis
D
Chakrabarty
C.S.I.R. -National Botanical Research Institute, Council of Scientific and Industrial Research, Lucknow 226001, India.
Prabodh K
PK
Trivedi
Department of Environmental Sciences, Babasaheb Bhimrao Ambedkar (Central) University, Rae bareily Road, Lucknow-226025, India.
Rana Pratap
RP
Singh
C.S.I.R. -National Botanical Research Institute, Council of Scientific and Industrial Research, Lucknow 226001, India. Electronic address: tripathi_rd@rediffmail.com.
Rudra Deo
RD
Tripathi
D000222:Adaptation, Physiological; D001151:Arsenic / Q000378:metabolism / Q000633:toxicity*; D003547:Cysteine Synthase / Q000235:genetics / Q000378:metabolism; D005838:Genotype; D005978:Glutathione / Q000235:genetics / Q000378:metabolism; D019803:Glutathione Disulfide / Q000378:metabolism; D005980:Glutathione Reductase / Q000235:genetics / Q000378:metabolism; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D012275:Oryza / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D018384:Oxidative Stress; D054811:Phytochelatins; D017382:Reactive Oxygen Species / Q000378:metabolism; D012989:Soil Pollutants / Q000378:metabolism / Q000633:toxicity*; D013438:Sulfhydryl Compounds / Q000378:metabolism* / Q000633:toxicity; D005723:gamma-Glutamyltransferase / Q000235:genetics / Q000378:metabolism
D017382:Reactive Oxygen Species; D012989:Soil Pollutants; D013438:Sulfhydryl Compounds; D054811:Phytochelatins; D005980:Glutathione Reductase; D005723:gamma-Glutamyltransferase; D005982:Glutathione Transferase; D003547:Cysteine Synthase; D005978:Glutathione; D001151:Arsenic; D019803:Glutathione Disulfide