β-氨基丁酸处理对桃果实采后灰霉病的影响及其诱导抗病模式研究

Investigation on the effects of β-aminobutyric acid treatment on gray mold decay in harvested peaches and the mode of the induced disease resistance

以"白凤"水蜜桃果实为试材,研究了β-氨基丁酸(β-aminobutyric acid,BABA)处理对桃果实由Botrgtis.cinerea导致的灰霉病的影响并分析其相关诱导抗病模式。结果显示,单一20 mmol/L BABA处理不能直接诱导未接种病原菌桃果实的防卫反应,但经BABA处理的桃果实在接种B.cinerea后,其展现出较单一B.cinerea接种而未进行BABA处理果实更为强烈的H2O2迸发、几丁质酶和β-1,3-葡聚糖酶活性上升以及Pp NPR1-like和Pp PRs基因表达,说明经BABA处理桃果实只在病原激发子侵染时才可表达出较强的系统抗性,由此可推断BABA诱导桃果实防卫反应的机制可归因于Priming(敏化)反应而不是直接诱导作用。此外,经BABA处理的桃果实在贮藏结束后未出现明显的品质劣变和抗氧化活性下降现象,说明Priming反应可有效平衡采后桃果实防卫反应和底物消耗。

The present study was conducted to investigate the effect of BABA treatment on gray mold disease caused by Botrytis cinerea in peaches（ Prunus persica Batsch cv ‘Baifeng＇） during the storage and to analyze the relative mode of the induced resistance. The results showed that the treatment with 20 mmol / L BABA alone was not able to activate the defense response in non-inoculated peaches directly. However,upon inoculated with the pathogen of B. cinerea previously,the BABA-treated peaches displayed a series of more significant augmented defense responses including stronger H2O2 burst,higher activities of chitinase and β-1,3-glucanase as well as higher expressions of Pp NPR1-like and Pp PRs. Thus,it was clear that BABA-induced resistance could be attributed to a Priming mechanism in peaches,since only the BABA-treated peaches exhibited an enhanced capacity to augment defense responses upon challenge with the pathogen. Moreover,the BABA-treated peaches did not show the remarkable quality deterioration and the decrease on antioxidant activity,indicating that priming mechanism could effectively balance the defense response expression and substrate costs in postharvest peaches.