癸醛抑制果蔬采后青霉属致病菌的分子机制研究

Decanal is a kind of safe, efficient, broad-spectrum and environment friendly inhibitive substance. It has obvious inhibitory effect on Penicillium expansum, the main postharvest pathogen of pome fruit and Penicillium digitatum, the main postharvest pathogen of citrus fruit. Both of them are major postharvest pathogen and quite harmful to fruit and vegetable preservation. In this study, the effects of decanal on growth and pathogenicity of P. expansum and P. digitatum were determined via assessments of physiological, biochemical and related molecular indexes firstly. Acting sites of decanal at transcriptome and proteome level in pathogen were then determined by techniques of Small RNA-sequencing, mRNA-sequencing, Isobaric tag for relative and absolute quantitation combining bioinformatics analysis. After that, The binary vectors of pCAMBIA 1300-HPH and agrobacterium mediated transformation were constructed to validate the biological function of some key target genes. Finally, the molecular mechanism of decanal against Penicillia was clarified.

癸醛是一种安全、高效、广谱并且环保的抑菌物质，对果蔬采后青霉属致病菌Penicillium expansum（梨果类采后主要病害）和Penicillium digitatum（柑橘类采后主要病害）具有明显的抑制作用。本文首先通过生理、生化及相关分子指标的检测，确定了癸醛对Penicillium expansum和Penicillium digitatum生长发育及致病力的影响；然后通过Small RNA-sequencing、mRNA-sequencing、Isobaric tag for relative and absolute quantitation结合生物信息学分析筛选出癸醛在病原菌转录组及蛋白质组水平的作用靶标；接着利用pCAMBIA 1300-HPH双元载体以及农杆菌介导的转化验证部分关键作用靶标基因的生物学功能，最终阐明癸醛抑制果蔬采后青霉属致病菌的分子机制。

Penicillium expansum和Penicillium digitatum是果蔬采后主要致病菌，每年对我国果蔬产业造成巨大的经济损失，开发新的采后防治策略及技术，具有重要的现实意义。癸醛（Decanal）作为一种环境友好的天然物质，具有抑菌能力强、防治范围广的优点。因此，本项目以P. expansum和P. digitatum为研究对象，筛选Decanal的最低抑菌浓度，通过生理、生化及其相关分子指标检测，确定了Decanal对P. expansum生长发育及致病力的调控机制，并对调控P. digitatum生长发育相关的长链非编码RNA（LncRNA）进行了鉴定与分析，主要研究结果如下：1）利用形态学结合分子生物学方法，确定了P. expansum的遗传背景及其毒素合成相关基因的表达图谱，鉴定出130个调控P. expansum孢子萌发的重要基因；2）确定癸醛的最低抑菌浓度为0.12 g/L，浓度达到0.24g/L时对苹果和梨果实青霉病具有良好的防治效果；3）利用RNA-sequencing及其iTRAQ (isobaric tags for relative and absolute quantitation)分别鉴定出3963和539个癸醛处理诱导的差异表达基因和蛋白；4）整合转录组和蛋白质组数据发现，癸醛主要影响P. expansum的代谢及遗传物质加工途径；5）进一步分析表明，癸醛能够通过干扰P. expansum的氧化磷酸化途径，限制胞内ATP的合成，进而抑制病原菌的发育；6）通过对不同发育时期P. digitatum高通量测序，检测到3957个发育相关的LncRNA和2175个mRNA，并对其相互关系进行了预测和整合。研究结果初步阐明Decanal对青霉属采后病害的抑菌机制，为进一步提高癸醛的防治效果及应用潜力提供理论基础，为今后开发新型杀菌剂的作用靶标提供新思路。