硅酸钠对粉红单端孢（Trichothecium roseum）胞外酶的调控机理

采后病原物与果实互作过程中，病原物通过分泌胞外酶、产生毒素和激素来引起寄主发病。在大多数采后病害的发病过程中，病原物分泌的胞外酶是重要致病因子，粉红单端孢（Trichothecium roseum）是重要的采后病原物，我们的前期研究发现硅酸钠对T. roseum具有良好的抑制效果，但其作用机理尚不明了。本项目结合前期研究基础，以T. roseum为研究对象，通过硅酸钠和对应pH处理，综合采用采后病理学、生物化学、细胞生物学和分子生物学等多学科方法，利用细胞化学定位、生物化学分析、实时荧光定量PCR（RT-PCR）及X-射线能谱扫描（SEM-EDAX）等技术手段，从生化、亚细胞和分子水平上解析硅酸钠处理过程中pH值以及硅和钠含量对T. roseum生长、致病力和胞外酶产生的调控机制。探明参与其调控的关键胞外酶基因，为硅酸钠在果实采后病害控制中的广泛应用提供新的理论依据。

Pathogen secretes extracellular enzyme, produces of toxins and hormone to cause decay during the interaction between fruit and pathogen. Extracellular enzyme secreted by pathogen is the important factor of pathogenicity in most pathogen-host interactions. Trichothecium roseum is a major pathogen of fruit during storage. Our previous study indicated that sodium silicate effectively inhibits T. roseum, however the mechanism remains unknown. In this proposal, T. roseum was chosen as material, multidisciplinary approaches involving postharvest pathology, biochemistry, cell biology and molecular biology will be used to analyze the regulation mechanism of pH, sodium and silicon on mycelia growth, pathogenicity and extracellular enzyme secretion of T. roseum treated with sodium silicate and corresponding pH values. The regulation mechanisms will be analyzed based on cytochemical technology, biochemical assays, RT-PCR and energy-dispersive X-ray microanalysis system fitted to scanning electron microscopy (SEM-EDAX) methods at biochemical, sub-cellular and molecular levels. Expected results of this project will elucidate the gene expression of key extracellular enzyme of T. roseum and provide the new theoretical basis for application of sodium silicate on control postharvest diseases of fruit.