梨果皮花青素合成通路响应病原菌侵染机制研究

花青素是果实中的常见色素，在果实应答病原菌侵染中的作用尚不清楚。文章利用黑曲霉的野生型菌株、抗氧化酶缺失相关菌株 $ \Delta cpeA $、 $ \Delta sodB $和 $ \Delta sodC $侵染砀山酥梨和红茄梨，发现富含花青素的红茄梨对黑曲霉具有较高的抵抗力。因此，分别用体积分数为0、5%、10%红茄梨提取的花青素处理大肠杆菌和黑曲霉，结果发现体积分数为5%、10%的花青素对大肠杆菌和黑曲霉都有不同程度的抑制作用。利用黑曲霉侵染红茄梨，通过实时荧光定量聚合酶链式反应（polymerase chain reaction，PCR）技术，分析梨侵染病变部位与花青素相关的基因表达量变化，发现PyMYB10、PyMYB114、PybHLH3、PyDFR、PyANS和PyUFGT表达量上调，结果表明，梨果实可能通过上调花青素合成通路抑制采后病原真菌黑曲霉的侵染。

Anthocyanin is a common pigment in fruit, and its role in fruit response to pathogen infection is unclear. In this paper, the wild type(WT) strains of Aspergillus niger(A. niger) and the related strains with deletion of antioxidant enzymes $ \Delta cpeA $, $ \Delta sodB $ and $ \Delta sodC $ were used to infect Dangshan pear and Starkrimson pear. Anthocyanin-rich Starkrimson pears were found to be highly resistant to A. niger. Therefore, the anthocyanins of Starkrimson pear were extracted, and Escherichia coli(E. coli) and A. niger were treated with 0, 5% and 10% anthocyanins, respectively, and it was found that 5% and 10% anthocyanins showed different inhibitory effects on both E. coli and A. niger. The Starkrimson pears were infected by A. niger, and the expression changes of anthocyanin-related genes in the infected lesions of pears were analyzed by RT-qPCR. The expression levels of PyMYB10, PyMYB114, PybHLH3, PyDFR, PyANS and PyUFGT were up-regulated, indicating that pear fruit may inhibit the infection of the postharvest pathogenic fungus A. niger by up-regulating the anthocyanin synthesis pathway.