AUTHOR=Tripathi Durgesh Kumar , Singh Swati , Singh Vijay Pratap , Prasad Sheo Mohan , Chauhan Devendra Kumar , Dubey Nawal Kishore TITLE=Silicon Nanoparticles More Efficiently Alleviate Arsenate Toxicity than Silicon in Maize Cultiver and Hybrid Differing in Arsenate Tolerance JOURNAL=Frontiers in Environmental Science VOLUME=4 YEAR=2016 URL=https://www.frontiersin.org/journals/environmental-science/articles/10.3389/fenvs.2016.00046 DOI=10.3389/fenvs.2016.00046 ISSN=2296-665X ABSTRACT=

Alleviation of abiotic stress by silicon (Si) is well documented. But mitigation of abiotic stress by silicon nanoparticles (SiNPs) is not much known. Therefore, hydroponic experiments were conducted to investigate if SiNPs are more effective than Si in mitigation of arsenate (AsV; 25 and 50 μM) toxicity in maize cultivar and hybrid differing in AsV tolerance. Under AsV stress, reduction in growth was accompanied by enhanced level of As and oxidative stress. AsV inhibited activities of antioxidant enzymes like ascorbate peroxidase, glutathione reductase, and dehydroascorbate reductase (except superoxide dismutase). The redox status of ascorbate and glutathione was disturbed by AsV as indicated by a steep decline in their reduced/oxidized ratios. However, addition of Si and SiNp ameliorates AsV toxicity in maize. Si and SiNp both could reduce AsV toxicity in maize cultivar and hybrid, which could be related with decreased accumulation of As and oxidative stress, and enhanced components of the ascorbate-glutathione cycle (AsA-GSH cycle). But lowering in the accumulation of As and oxidative stress markers, and enhancement in components of the AsA-GSH cycle was prominent in SiNp fed seedlings under AsV stress. The results also showed that SiNp are more effective in reducing AsV toxicity than Si, which is due to their greater availability to seedlings. Comparing responses of cultivar and hybrid, maize cultivar shows more resistance against AsV than hybrid.