Sebastian Abin, Prasad M N V
Department of Plant Sciences, University of Hyderabad, Hyderabad 500046, India.
Department of Plant Sciences, University of Hyderabad, Hyderabad 500046, India.
J Photochem Photobiol B. 2014 Aug;137:135-43. doi: 10.1016/j.jphotobiol.2013.12.011. Epub 2013 Dec 28.
Cadmium (Cd) accumulation and related stress responses have been investigated in red, blue and white lights exposed Oryza sativa L. cv MTU 7029. Cd translocation was reduced significantly by red and blue lights. Increase in amount of organic acids, thiols, and nutrients in the roots that cause Cd rhizocomplexation was the reason for reduction in Cd translocation. These effects were due to higher efficiency to perform photosynthesis and transpiration under red or blue lights compare with white light during Cd stress. Increased photosynthetic assimilate turnover was witnessed as a function of sugar content. Amount of redox regulators such as glutathione and ascorbate were also increased under red and blue light exposure. Together with up regulation of antioxidant enzyme activities, these metabolites ensured redox balance in presence of reactive oxygen species produced due to Cd toxicity. Protection of photosynthesis from Cd inducible oxidative stress ensured supplies of sugar intermediates essential for the synthesis of metal chelators in roots. Therefore, it was inferred that red and blue lights promote Cd rhizocomplexation and ameliorated Cd stress in rice seedlings.
已对暴露于红、蓝和白光下的水稻品种MTU 7029中的镉（Cd）积累及相关应激反应进行了研究。红光和蓝光显著降低了Cd的转运。根系中导致Cd根际络合的有机酸、硫醇和养分含量增加是Cd转运减少的原因。这些影响是由于在Cd胁迫期间，与白光相比，红或蓝光下进行光合作用和蒸腾作用的效率更高。光合同化物周转率的增加表现为糖含量的函数。在红光和蓝光照射下，氧化还原调节剂如谷胱甘肽和抗坏血酸的含量也增加。这些代谢物与抗氧化酶活性的上调一起，确保了在Cd毒性产生的活性氧存在下的氧化还原平衡。保护光合作用免受Cd诱导的氧化应激，确保了根系中金属螯合剂合成所需的糖中间体的供应。因此，推断红光和蓝光促进了水稻幼苗中Cd的根际络合并减轻了Cd胁迫。
