橙皮素对烟草青枯病的诱导抗性研究

为探究类黄酮诱导烟草抗青枯病的生理机制，从12种类黄酮化合物中筛选出对烟草青枯病防治效果最好的橙皮素，并对橙皮素处理后烟草叶片过氧化氢沉积、防御酶活性以及相关基因的表达量等进行了分析。结果表明，1 mmol/L橙皮素对青枯菌无直接的抑菌作用，但对青枯病具有较明显的防控效果。橙皮素灌根处理诱发接种青枯菌烟草叶片过氧化氢的积累，显著提高叶片过氧化物酶（POD）和苯丙氨酸解氨酶（PAL）的活性以及烟株次生代谢产物中酚类和类黄酮含量，上调表达NtPR1a、NtNPR1、NtPAL抗性基因，从而提高烟株对青枯病的抗性。由此可知，橙皮素可作为诱抗剂有效防控青枯病的发生。

Study on the Effect of Hesperetin on the Induction of Tobacco Resistance to Bacterial Wilt

In order to explore the mechanism of hesperetin inducing tobacco plants' resistance to bacterial wilt, hesperetin with the best control effect against tobacco bacterial wilt was screened from 12 flavonoids, and the accumulation of H₂O₂, the activities of leaf defense enzymes, and the expression of genes related to disease resistance were analyzed and determined. The results showed that hesperetin had no antibacterial effect at a low concentration of 1 mmol/L, but had obvious effect on inducing tobacco plants' resistance to bacterial wilt. Hesperetin irrigation caused H₂O₂ deposition, significantly increased the activities of peroxidase (POD), phenylalanine lyase (PAL) and the content of secondary metabolites phenols and flavonoids. In addition, the expression of resistance genes NtPR1a, NtNPR1, and NtPAL was up-regulated, thereby improving the resistance of tobacco plants to bacterial wilt. Therefore, hesperetin could be used as bacterial wilt inducers to effectively control the occurrence of bacterial wilt.