N Priyanka, N Geetha, T Manish, S V Sahi, P Venkatachalam
Plant Genetic Engineering and Molecular Biology Lab, Department of Biotechnology, Periyar University, Periyar Palkalai Nagar, Salem, 636 011, Tamil Nadu, India.
Department of Botany, Bharathiar University, Coimbatore, 624 046, Tamil Nadu, India.
Toxicol Rep. 2021 Jan 27;8:295-302. doi: 10.1016/j.toxrep.2021.01.016. eCollection 2021.
Cadmium (Cd) and Lead (Pb) heavy metal pollution induced toxicity severely affects the plant growth and yield of various agriculutral crops worldwide. The present study discuss the prime role of phycomolecules coated zinc oxide nanoparticles (ZnONPs) application on development of heavy metal tolerance mechanism in cotton ( L.) seedlings better than exposed to Cd and Pb treatments alone. Co-exposure of ZnONPs along with heavy metal treatments significantly promoted the shoot, and root growth as well as biomass compared to control, while it was down-regulated in Cd and Pb exposed seedlings. The intervention of ZnONPs had up-regulated the level of chlorophyll , and carotenoid contents in leaves grown under Cd and Pb treatments than the untreated control. Similarly, the level of total soluble protein and malondialdehyde (MDA-lipid peroxidation) contents was significantly increased in the co-presence of ZnONPs along with Cd and Pb treatments over their respective control. Accumulation of antioxidant defense enzymes viz., superoxide dismutase (SOD), catalase (CAT), peroxidase (POX) and ascorbate peroxidase (APX) was up-regulated significantly in seedlings upon co-exposure of ZnONPs with Cd and Pb treatments. Random amplified polymorphic DNA (RAPD) fingerprinting analysis exhibited no genomic changes/alterations in seedlings by co-existence of ZnONPs with heavy metals. Overall, the present results indicate that the addition of ZnONPs with Cd and Pb ion exposure protects cotton seedlings by alleviating heavy metal induced phytotoxicity and promoted physiochemical characteristics via differential regulation of photosynthetic machinery as well as antioxidative defense mechanisms in cotton seedlings. Results strongly suggest that phycomolecule coated ZnO nanoparticles could be effectively used as nanofertilizer to cultivate agronomically important crops in heavy metal polluted soil in the future.
镉（Cd）和铅（Pb）重金属污染引发的毒性严重影响着全球各种农作物的生长和产量。本研究探讨了藻分子包覆的氧化锌纳米颗粒（ZnONPs）在棉花（L.）幼苗重金属耐受机制形成过程中所起的主要作用，其效果优于单独进行镉和铅处理。与对照组相比，ZnONPs与重金属处理共同作用显著促进了棉苗地上部和根系生长以及生物量的增加，而在单独镉和铅处理的棉苗中则受到抑制。与未处理的对照相比，ZnONPs的介入使镉和铅处理下叶片中的叶绿素、 和类胡萝卜素含量上调。同样，ZnONPs与镉和铅处理共同存在时，总可溶性蛋白水平和丙二醛（MDA - 脂质过氧化）含量相对于各自的对照显著增加。抗氧化防御酶即超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、过氧化物酶（POX）和抗坏血酸过氧化物酶（APX）在ZnONPs与镉和铅处理共同作用的棉苗中显著上调。随机扩增多态性DNA（RAPD）指纹分析表明，ZnONPs与重金属共存对棉苗基因组无变化/改变。总体而言，目前的结果表明，添加ZnONPs与镉和铅离子共同作用可减轻重金属诱导的植物毒性，通过差异调节棉花幼苗的光合机制和抗氧化防御机制来保护棉苗，并促进其理化特性。结果强烈表明，藻分子包覆的ZnO纳米颗粒未来可有效用作纳米肥料，用于在重金属污染土壤中种植具有重要农学意义的作物。
