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

Influence of protein damage and proteasome gene expression in longevity of recalcitrant Madhuca latifolia Roxb. seeds

Enhanced cellular damage during desiccation is considered to be one of the key factors limiting vigour and viability of seeds. The uncontrolled accumulation of reactive oxygen species and resultant damaging reactions such as the oxidation of lipids and DNA in desiccating seeds of Madhuca latifolia (Roxb.) J. F. Macbr. has already been well characterized. However, hydrolytic and (or) oxidative damage to proteins requires further study. This study investigated the desiccation-induced oxidative damage to proteins and proteolytic systems in recalcitrant M. latifolia seeds during ambient storage. Seeds experienced a significant drop in seed water content [ca. 1.32 to ca. 0.23 g·(g dry mass)−1] during storage resulting in complete loss of viability after 35 days of storage. A considerable decline in total protein content (3.0–3.6 fold) and activity (4.8–13.8 fold) in the gene expressions of proteasome subunits (α, β, and E2) were recorded in the embryonic axis of desiccating M. latifolia seeds. In contrast, increases in the level of protein carbonyls (2.46 fold), hydroperoxides (2.31 fold), malondialdehyde- and 4-hydroxy-2-nonenal-protein adducts (1.8 and 3.9 fold), and Amadori and Maillard reaction products, along with proteases (14.5–30.4 fold) were observed in desiccating M. latifolia seeds. This study revealed that increased oxidation/modification of proteins and proteasome dysfunction are involved in the deterioration of desiccating M. latifolia seeds.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author