Publication:
Induction of ascorbate and guaiacol specific peroxidases in metal and water deficit induced oxidative stress in rice seedlings

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dc.contributor.authorSharma, P.
dc.contributor.authorJha, A.B.
dc.contributor.authorVerma, S.
dc.contributor.authorDubey, R.S.
dc.date.accessioned2025-03-04T05:30:19Z
dc.date.available2025-03-04T05:30:19Z
dc.date.issued2006
dc.description.abstractPlants possess two distinguished forms of peroxidases, namely ascorbate peroxidase (APX) and guaiacol peroxidase (GPX). The contribution of both forms was studied in rice seedlings as part of defense mechanism against water deficit as well as metal imposed oxidative stress. The metals Pb2+ and As3+ were freely absorbed by roots of rice plants from growth medium in sand cultures but were mainly localized in roots. Rice seedlings grown for 20 days in Hoagland nutrient solution in sand cultures containing either 500 μM and 1000 μM Pb2+, 80 μM and 160 μM Al3+ or 25 μM and 50 μM As3+ or when seedlings grown for 20 days in nutrient solution were subjected to 24 h water stress treatment of -0.5 MPa or -2.0 MPa showed elevated levels of lipid peroxides. Lipid peroxidation paralleled with increased APX activity in Pb2+, Al3+, As3+ as well as water stressed seedlings. Seedlings growing in presence of metal salts showed increased GPX activity, however GPX activity was higher in moderately water stressed (-0.5 MPa) seedlings and it declined with higher level (-2.0 MPa) of water stress. Induced activity of GPX and elevated level of lipid peroxidation were higher in roots compared to shoots however the induced activity of APX was higher in shoots. Two isoforms of APX when purified from leaves of 20 day grown rice seedlings showed very high affinity for H 2O2 and ascorbate and very little affinity for guaiacol. Activity staining in polyacrylamide gels revealed the induction of two new isoforms of GPX in roots of Al3+ as well as As3+ treated seedlings where as one new isoform of APX was induced in shoot of water and Al3+ stressed seedlings. Both ascorbate and guaiacol specific peroxidases appear to be important components of antioxidative defense mechanism under conditions of metal toxicity and water stress.
dc.identifier.doihttps://doi.org/nan
dc.identifier.issn9715894
dc.identifier.urihttps://dl.bhu.ac.in/ir/handle/123456789/87236
dc.titleInduction of ascorbate and guaiacol specific peroxidases in metal and water deficit induced oxidative stress in rice seedlings
dc.typeArticle
dspace.entity.typePublication
journal.titlePhysiology and Molecular Biology of Plants
journalvolume.identifier.volume12

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2006