Modulation of arsenic-induced oxidative stress and protein metabolism by diphenyleneiodonium, 24-epibrassinolide and proline in Glycine max L.

Arsenic (As)-toxicity is a major constraint for crop production. The present study was intended to examine the comparative ameliorative effects of diphenyleneiodonium (DPI), 24-epibrassinolide (EBL) and proline (Pro) on As-stress in Glycine max L. Seeds of Glycine max L. were subjected to As (100 μM) singly, and together with DPI (10 μM), EBL (0.5 μM) or Pro (10 mM), for five days, and were then analyzed. Experimental results showed that As treatment caused a substantial fall in growth traits like germination percentage, radicle length and dry mass, which was accompanied by As accumulation. Additionally, As application also revealed reduced viability, total protein content and activities of antioxidative enzymes (superoxide dismutase, catalase and ascorbate peroxidase), while it increased the levels of total sugar, proline and oxidative stress markers such as electrolyte leakage, reactive oxygen species, lipid oxidized products, protein carbonyls and hydroperoxides, Amadori and Maillard reaction products, malondialdehyde-/4-hydroxy-2-nonenal-protein adducts, protease and proteasome. Isozymes of antioxidative enzymes were also observed to be altered considerably under As-stress. Impressively, DPI, EBL and Pro played their role as protective agents, hence caused enhanced growth and reduced As accumulation. These protective chemicals also improved the viability, accruals of total protein, total sugar and endogenous proline, and activities of antioxidants, while they reduced the levels of oxidative stress markers. Our findings demonstrated the involvement of DPI, EBL and Pro in As-stress tolerance in Glycine max L. Further, Pro appears to be superior to DPI and EBL, in alleviating As-induced responses in Glycine max L

Modulation of nickel toxicity by glycinebetaine and aspirin in Pennisetum typhoideum

Germinated Pennisetum typhoideum seeds were grown under phytotoxic amount of nickel (Ni) and its combinations with aspirin (Asp) and/or glycinebetaine (GB). The results revealed that exposure to Ni caused reduced growth and membrane stability index of P. typhoideum, which were correlated with the accumulated Ni and reactive oxygen species. Oxidative stress markers; malondialdehyde, 4-hydroxy-2-nonenal and lipoxygenase were also elevated by Ni, while were diminished significantly by exogenously applied Asp and/or GB. However, considerable loss in protein and DNA contents were discernible in Ni subjected tissues, but were stimulated largely in the Asp and/or GB applied radicles. Additionally, alteration in the activities and native-PAGE profiles of antioxidant enzymes (superoxide dismutase, catalase, guaiacol peroxidase and ascorbate peroxidase) were discernible in response to Ni, which are reputed to counterbalance the oxidative condition. However, exogenous addition of Asp and/or GB activated the defense system and uplifted proline accumulation in stressed P. typhoideum. The results approved that combined addition of Asp and GB performed far better in Ni-stress mitigation than their alone application. Conducted study indicated that combined application of Asp and GB served as complementary tool to confer tolerance by up-regulating the antioxidant enzymes and thus can be implicated in the mitigation of Ni-toxicity