番茄果实感染灰霉病过程中H_2O_2的抗病作用

Effect of H2O2on Disease Resistance of Postharvest Tomato Fruits Infected with Botryis cinerea

以采后番茄果实为材料,对发病过程中过氧化氢(hydrogen peroxide,H2O2)诱导的抗病作用进行研究。采用浓度10mmol/L H2O2处理番茄,1d后进行损伤接种实验。只进行损伤处理为对照组,只损伤接种灰霉菌为inoc组,先用H2O2处理再损伤接种灰霉菌为inoc+H2O2+组,然后置于(25±1)℃,80%～85%RH条件下贮藏。结果表明:inoc组与对照组相比可以明显提高番茄果实的发病率和病斑面积,接种后第3天,inoc+H2O2+组和inoc组相比,发病率降低了35.5%,病斑面积减小了29.7%。inoc+H2O2+组在1～2d可以显著诱导苯丙氨酸解氨酶(phenylalnineammonialyase,PAL)和多酚氧化酶(polyphenol oxidase,PPO)的活性,在1～4d可以显著诱导葡聚糖酶(glucanase,GLU)和几丁质酶(chitinase,CHI)的活性,在30min时能够诱导抗病相关蛋白PR-1基因的相对表达量出现高峰,达到inoc组的2.3倍。inoc+H2O2+处理组在1d内可以明显提高其合成酶NADPH氧化酶的相对表达量,从而提高番茄体内H2O2的含量,起到信号分子作用,诱导番茄的内源抗性。可见,在番茄果实发病过程中,H2O2信号分子能够诱导抗性,从而提高番茄果实的抗病能力。

The disease-resistant effect of H2O2 on post-harvest tomato fruits infected with Botryis cinerea was investigated. Freshly harvested tomato fruits were treated with 10 mmol/L H2O2. One day later, the treated fruits were subjected to establish wound models including mechanical wound and inoculation of Botryis cinerea. The wounded fruits were divided into three groups with mechanically wounded fruits as the control group, the Botryis cinerea-inoculated fruits as the inoc group, and HEOE-pretreated fruits coupled with Botryis cinerea-inoculated fruits as the inoc ＋H2O2group. All fruits were stored the environment with temperature of （25 ＋ 1） ℃ and RH of 80%-85% for 4 days. The results showed that inoc treatment could significantly improve the incidence and lesion area of tomato fruits compared with the control group. After inoculation for 3 days, inoc ＋ H2O2 treatment could reduce disease incidence by 35.5% and lesion area by 29.7% compared with the inoc treatment. In addition, inoc ＋ H2O2 treatment could significantly improve the activities of disease defense- related enzymes such as PAL and PPO during 1-2 days, GLU and CHI during 1-4 days and induce gene expression level of disease-related protein PR-1. Meanwhile, inoc ＋ H202 treatment could significantly improve the relative expression level of NADPH oxidase within 1 day, thereby increasing internal H2O2 content as a signal molecule could induce the disease resistance in tomato fruits. In a word, H2O2 can improve the disease resistance of tomato fruits infected with Botryis cinerea.