Qiu Cheng-Wei, Zhang Can, Wang Nian-Hong, Mao Weihua, Wu Feibo
Department of Agronomy, Zhejiang Key Laboratory of Crop Germplasm, College of Agriculture and Biotechnology, Zijingang Campus, Zhejiang University, Hangzhou, 310058, China; Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou, 225009, China.
Department of Agronomy, Zhejiang Key Laboratory of Crop Germplasm, College of Agriculture and Biotechnology, Zijingang Campus, Zhejiang University, Hangzhou, 310058, China.
Environ Pollut. 2021 Jan 15;273:116486. doi: 10.1016/j.envpol.2021.116486.
Cadmium (Cd) in the food chain poses a serious hazard to human health. Therefore, a greenhouse hydroponic experiment was conducted to examine the potential of exogenously strigolactone GR24 in lessening Cd toxicity and to investigate its physiological mechanisms in the two barley genotypes, W6nk2 (Cd-sensitive) and Zhenong8 (Cd-tolerant). Exogenous application of 1 μM GR24 (strigol analogue) reduced the suppression of growth caused by 10 μM Cd, lowered plant Cd contents, increased the contents of other nutrient elements, protected chlorophyll, sustained photosynthesis, and markedly reduced Cd-induced HO and malondialdehyde accumulation in barley. Furthermore, exogenous GR24 markedly increased NO contents and nitric oxide synthase activity in the Cd-sensitive genotype, W6nk2, effectively alleviating the Cd-induced repression of the activities of superoxide dismutase and peroxidase, increasing reduced glutathione (GSH) and ascorbic acid (AsA) pools and activities of AsA-GSH cycle including ascorbate peroxidase, glutathione peroxidase, glutathione reductase, dehydroascorbate reductase and monodehydroascorbate reductase. The findings of the present study indicate that GR24 could be a candidate for Cd detoxification by decreasing Cd contents, balancing nutrient elements, and protecting barley plants from toxic oxidation via indirectly eliminating reactive oxygen species (ROS), consequently contributing to reducing the potential risk of Cd pollution.
食物链中的镉（Cd）对人类健康构成严重危害。因此，进行了一项温室水培实验，以研究外源独脚金内酯GR24减轻镉毒性的潜力，并探究其在两种大麦基因型W6nk2（镉敏感型）和浙农8号（镉耐受型）中的生理机制。外源施加1 μM GR24（独脚金类似物）可减轻10 μM镉对生长的抑制作用，降低植物镉含量，增加其他营养元素的含量，保护叶绿素，维持光合作用，并显著减少镉诱导的大麦中过氧化氢（HO）和丙二醛的积累。此外，外源GR24显著增加了镉敏感基因型W6nk2中的一氧化氮（NO）含量和一氧化氮合酶活性，有效缓解了镉诱导的超氧化物歧化酶和过氧化物酶活性的抑制，增加了还原型谷胱甘肽（GSH）和抗坏血酸（AsA）的含量以及AsA-GSH循环中包括抗坏血酸过氧化物酶、谷胱甘肽过氧化物酶、谷胱甘肽还原酶、脱氢抗坏血酸还原酶和单脱氢抗坏血酸还原酶的活性。本研究结果表明，GR24可通过降低镉含量、平衡营养元素以及通过间接清除活性氧（ROS）保护大麦植株免受氧化毒性，从而成为镉解毒的候选物质，进而有助于降低镉污染的潜在风险。
