茶树精油对果实采后病原真菌亚细胞功能的干扰及其分子机制研究

The fungal disease is the main reason for postharvest losses of fruit, and the researches focused on the new biological control methods to control disease. In previous test, tea tree oil (TTO) can cause the alternations of subcellular structure, such as cell membrane and mitochondria. In this program, we will reveal the interference effects and molecular mechanism of TTO and it's main components (terpinen-4-ol,1,8-Cineole) on the subcellular function of Botrytis Cinerea and Penicillium expansum in vitro condition. The functional disturbance manner will be indicated by studing the permeability and chemical composition changes of fungal cell membrane, combined with the constuction of liposomes as membrane model. The mitochondrial membrane potential, respiratory chain function, reactive oxygen species (ROS) level and relative metablolism will be determined. The molecular mechanism will be revealed by using the gene chip technology to analyz the changes of fungal gene expression profiles, and then the key regulatory pathways and differentially expressed genes will be analyzed and validated. The results of this program will reveal the mechanism of essential oil on the fungi disease, and enrich the theory basis in postharvest research field. Meanwhile, these studies will provid some guide to promote the commercial application of essential oils on the fruit preservation.

病原真菌侵染是果实采后损失的主要原因，探寻新型生物防治方法是当今研究热点。前期研究发现，茶树精油（TTO）抑菌作用与真菌细胞膜和线粒体等主要亚细胞微观结构变化有关，但具体的干扰机制尚不明确。本项目以采后2种主要致病菌- - 灰葡萄孢霉、扩展青霉为研究对象，开展TTO及其差异组分（松油烯-4-醇、1,8-桉叶素）的体外抑菌试验，研究真菌细胞膜化学组成和物理性能变化，结合所构建脂质体细胞膜模型的损伤来阐明TTO对细胞膜功能干扰的方式；分析线粒体膜电位、呼吸链功能、 ROS(活性氧)水平及相关代谢酶类，反映TTO对线粒体功能的影响。利用微阵列基因芯片检测真菌基因表达谱变化，分析并验证与上述功能干扰相关的关键调控通路和差异表达基因，明确其分子机制。本项目的研究成果，一方面在精油抗菌理论上有所突破，丰富采后研究领域的学术内容；另一方面也可为TTO的商业应用、技术改进和精油复配等提供必要的科学理论指导。