Differential response of arsenic stress in two varieties of Brassica juncea L.
Present study showed the toxicity caused by Arsenite (As(III)) and its detoxification responses in two varieties (Varuna and Pusa Bold) of Brassica juncea. Comparisons were made in leaves and roots of both the varieties, which showed that the accumulation pattern in both the varieties were dose and duration dependent, being more in roots for two days and in leaves for four days. Increase/decrease of antioxidant enzymes activities (SOD, CAT, GPX) showed not much changes at the given concentrations except that the enzyme activities showed significant increase at the lower concentrations. Semi quantitative RT-PCR analysis of PCS showed more expression of its transcript in P. Bold as compared to Varuna variety due to As(III) stress. The analysis of isoenzyme pattern in leaves of P. Bold showed five and two major bands of SOD and GPX, respectively. As(III) treatment leads to the activation of MAPK activity indicating role of this important cascade in transducing As(III) mediated signals. The data presented indicates the differential responses in both the varieties and also that the increased tolerance in P. Bold may be due to the defensive role of antioxidant enzymes, induction of MAPK and up regulation of PCS transcript which is responsible for the production of metal binding peptides.
Gupta
Meetu
M
Department of Biosciences, Jamia Millia Islamia, Maulana Mohammad Ali Jouhar Marg, Jamia Nagar, New Delhi-110025, India. meetu_gpt@yahoo.com
Sharma
Pallavi
P
Sarin
Neera Bhalla
NB
Sinha
Alok Krishna
AK
D019881:Aminoacyltransferases / Q000378:metabolism; D018053:Arsenites / Q000493:pharmacokinetics / Q000633:toxicity*; D002374:Catalase / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D005979:Glutathione Peroxidase / Q000378:metabolism; D009149:Mustard Plant / Q000187:drug effects* / Q000378:metabolism; D018515:Plant Leaves / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013045:Species Specificity; D013482:Superoxide Dismutase / Q000378:metabolism; D013997:Time Factors
D018053:Arsenites; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D019881:Aminoacyltransferases; C093784:glutathione gamma-glutamylcysteinyltransferase; C015001:arsenite