School of Agronomy, Anhui Agricultural University, Hefei, 230036, PR China; MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, PR China.
MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, 310058, PR China.
Chemosphere. 2018 Dec;212:645-653. doi: 10.1016/j.chemosphere.2018.08.133. Epub 2018 Aug 27.
Polyamines are important bioactive molecules involved in regulating HO homeostasis, which is recognized as a major stimulus of oxidative stress under aluminum (Al) exposure. In this study, we investigated the involvement of spermidine oxidation in Al-induced oxidative stress, and its modulation by exogenous putrescine (Put) in two wheat genotypes differing in Al tolerance. Aluminum caused more severe oxidative damage at the root apexes in the Al-sensitive genotype Yangmai-5 than in the tolerant Xi Aimai-1, but these effects were significantly reversed by exogenous Put and polyamine oxidase (PAO) inhibitors. Aluminum caused a more significant increase in cell wall-bound PAO (CW-PAO) activity in Yangmai-5 than in Xi Aimai-1. Inhibiting of CW-PAO reduced HO accumulation, restored Spd decline in both genotypes, indicating its potential role in Al-induced HO production through catalyzing Spd oxidation. Additionally, Al significantly increased the activity of plasma membrane-NADPH oxidase, another HO generator, in wheat roots. Put application significantly inhibited the activity of CW-PAO and plasma membrane-NADPH oxidase, and reduced HO accumulation in Al-stressed wheat roots. Antioxidant enzymes were significantly stimulated by Al, but not Put. Overall, Put may protect wheat roots against Al-induced oxidative stress through regulating HO production by inhibiting CW-PAO and plasma membrane-NADPH oxidase.
多胺是参与调节 HO 动态平衡的重要生物活性分子，HO 动态平衡被认为是铝（Al）暴露下氧化应激的主要刺激因素。在这项研究中，我们研究了 spermidine 氧化在 Al 诱导的氧化应激中的作用，以及外源性腐胺（Put）对两种耐 Al 性不同的小麦基因型的调节作用。铝在 Al 敏感基因型扬麦 5 的根尖造成更严重的氧化损伤，而在耐 Al 性基因型西农 8 号则没有那么严重，但这些影响可以通过外源性腐胺和多胺氧化酶（PAO）抑制剂显著逆转。铝在扬麦 5 中引起的细胞壁结合多胺氧化酶（CW-PAO）活性的增加比在西农 8 号中更为显著。抑制 CW-PAO 减少了 HO 的积累，恢复了两种基因型中 Spd 的下降，表明它通过催化 Spd 氧化在 Al 诱导的 HO 产生中可能具有潜在作用。此外，铝在小麦根中显著增加了质膜-NADPH 氧化酶的活性，质膜-NADPH 氧化酶也是一种 HO 生成酶。腐胺的应用显著抑制了 CW-PAO 和质膜-NADPH 氧化酶的活性，并减少了 Al 胁迫下小麦根中 HO 的积累。抗氧化酶被 Al 显著刺激，但不受腐胺影响。总的来说，腐胺可能通过抑制 CW-PAO 和质膜-NADPH 氧化酶来调节 HO 的产生，从而保护小麦根免受 Al 诱导的氧化应激。
