橙皮素对烟草青枯病的诱导抗性研究

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

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。

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 H_(2)O_(2),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 H_(2)O_(2) 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.