ABSTRACT This research aims to assess the effect of Pichia guilliermondii treatment on the improved disease resistance of the peach fruit and to explore the biocontrol mechanisms. Infection rate and lesion diameter of the yeast-treated fruit were substantially inhibited after Rhizopus stolonifer and Penicillium expansum infection, respectively. A significant increase in endogenous salicylic acid (SA) content was stimulated in peach fruit treated with P. guilliermondii. The activities of defense-related enzymes and the SA synthase in peaches were also improved after P. guilliermondii treatment, and the expression of pathogenesis-related genes was activated. Thus, P. guilliermondii may be a biological elicitor-activated systemic acquired resistance by the SA signaling pathway. The new understanding regarding the mechanism of antagonist yeast could could be conducive for controlling fruit postharvest diseases in the future.

中文翻译：

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Pichia guilliermondii诱导桃果实抗性及其可能机制

摘要 本研究旨在评估毕赤酵母处理对改善桃果实抗病性的影响，并探讨其生防机制。分别在根茎根霉和膨胀青霉感染后，酵母处理果实的感染率和病斑直径得到显着抑制。在用 P. guilliermondii 处理的桃果实中，内源性水杨酸 (SA) 含量显着增加。P. guilliermondii处理后桃中防御相关酶和SA合成酶的活性也得到提高，致病相关基因的表达被激活。因此，P. guilliermondii 可能是通过 SA 信号通路的生物诱导物激活的系统性获得性抗性。