Plants counteract Cd toxicity by activating cellular stress responses. The simultaneous exogenous application of methyl jasmonate (MeJA) and methyl-β-cyclodextrin (CD) before Cd exposure improved the response of Arachis hypogaea hairy root culture to the unfavourable effects of Cd toxicity. At 24 h after elicitation, genes that encode key enzymes in the phenylpropanoid biosynthesis pathway (i.e., PAL and RS3) were up-regulated to 3.2- and 5.4-fold changes respectively, thereby inducing stilbene production. The up-regulation of genes that encode transcription factors (i.e., ERF1 and ERF6) significantly increased the expression of several genes (PR4A, PR5, PR10, and chitinase) that encode the pathogenesis-related (PR) proteins to 25.8-, 45-, 5- and 12.6-fold changes, respectively. The more dramatic up-regulation of PR protein-encoding genes demonstrated the significant role of defence proteins in plant protective mechanisms. The prolonged (i.e., 72-h) treatment with MeJA + CD_Cd triggered adaptive responses by substantially increasing the levels of antioxidants, stilbenes, and other phenolic substances. These findings suggest that the interaction between signalling elicitors (MeJA and CD) and Cd modulates a complex signalling network for plant defence system.

中文翻译：

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外源信号分子对镉胁迫下花生毛根适应性反应的增强

植物通过激活细胞应激反应来抵消 Cd 毒性。在镉暴露前同时外源应用茉莉酸甲酯 (MeJA) 和甲基-β-环糊精 (CD) 改善了花生毛状根培养物对镉毒性不利影响的反应。诱导后 24 小时，编码苯丙烷生物合成途径（即 PAL 和 RS3）关键酶的基因分别上调至 3.2 倍和 5.4 倍，从而诱导二苯乙烯的产生。编码转录因子（即 ERF1 和 ERF6）的基因的上调使编码发病机制相关 (PR) 蛋白的几种基因（PR4A、PR5、PR10 和几丁质酶）的表达显着增加至 25.8-、45- 、 5 倍和 12.6 倍的变化，分别。PR 蛋白编码基因更显着的上调证明了防御蛋白在植物保护机制中的重要作用。用 MeJA + CD_Cd 长时间（即 72 小时）处理通过显着增加抗氧化剂、芪和其他酚类物质的水平来触发适应性反应。这些发现表明信号诱导子（MeJA 和 CD）和 Cd 之间的相互作用调节了植物防御系统的复杂信号网络。