The toxicity of increasing heavy metal ion in soil has been threatening the food security and environments. In this study, we used Brassica rapa variety Qinggen #1, a leafy and oil vegetable, to investigate the effects of coper ion (Cu2+) on adaptive defense to understand regulatory molecular mechanisms. The variety exhibited a high tolerance at high Cu2+ concentration (200 mg L−1). More increases in superoxide radical, hydrogen peroxide, malondialdehyde, and proline were observed at higher concentration than low concentrations. Enzyme activities of SOD, GR, CAT, and APX were significantly altered earlier than corresponding expression of coding genes was up-regulated, indicating two distinct regulations at enzyme and gene levels. The CAT activity and expression correlated with the reactive oxygen species levels, indicating a more important role than other enzymes. Taken together, the high tolerance to Cu2+ in B. rapa is resulting from changes in biochemistry, enzyme, and gene expression.

中文翻译：

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植物化学和基因表达揭示了芸苔中铜离子的抗氧化反应

土壤中重金属离子增加的毒性已经威胁到粮食安全和环境。在本研究中，我们使用油菜品种青根 #1（一种多叶油料蔬菜）来研究铜离子 (Cu2+) 对适应性防御的影响，以了解调节分子机制。该品种在高 Cu2+ 浓度（200 mg L-1）下表现出高耐受性。与低浓度相比，在较高浓度下观察到超氧自由基、过氧化氢、丙二醛和脯氨酸的增加更多。SOD、GR、CAT 和 APX 的酶活性在编码基因的相应表达上调之前显着改变，表明酶和基因水平有两种不同的调节。CAT 活性和表达与活性氧水平相关，表明比其他酶更重要的作用。综上所述，B. rapa 对 Cu2+ 的高耐受性是由生物化学、酶和基因表达的变化引起的。