盐生植物特异性招募"黑化"内生真菌的基础生物学研究

前期完成了多种荒漠盐生植物内生真菌群落调查，发现"黑色素化"真菌（MEF）高强度侵染整个植株，表明适逆植物招募MEF具有一定的普遍性。为了破解这种全局性定植模式的生态学意义，本研究对MEF的基础生物学开展如下工作：（1）利用实时定量PCR 和模拟微环境技术，研究代表性MEF在宿主组织中的相对生物量及与宿主之间的感应效应；（2）定性定量分析MEF在不同条件下产激素、海藻糖和黑色素等与植物生长和胁迫反应相关的活性物质的性能；（3）研究MEF在不同盐浓度胁迫下的生长和耐性；（4）以水稻为模式植物，研究在不同盐浓度胁迫条件下接种单个、群体MEF对植株生长和生理（渗透调节物质和活性氧ROS）的影响。研究结果将揭示MEF与宿主之间进化形成的特异性共生关系并初步阐明MEF协同植物抗逆的物质基础、潜力和调控机制，对深入认识植物适逆的进化策略具有重要的科学意义；同时也为开发植物抗逆型真菌制剂开辟一条新途径。

The endophytic fungal community associated with several halophytes was investigated. It has been shown that the melanized endophytes(MEF) can extensively colonize both below and above ground host tisseus, this indicates that recruitment of MEF by stress-adapted plants is common. To elucidate the ecological roles of this global distribution pattern of MEF in hosts,in this project, we mainly focus on the basic biology of MEF in the following aspects: first,determination of relative biomass of MEF in hosts (based on fungus/plant DNA ratio) using real-time PCR; also, method of micro-environment simulation will be used to investigate the chemical sensing effect between MEF and host. Second, phytohormones, trehalose and melanin produced by MEF, which maybe responsibe for regulating plant growth and abiotic stress, are measured under different conditions. Third, growth and salt tolerance of MEF under a series of concentration of salt will be determined. Last, using rice as model plant,the effects of individual and community MEF on rice growth and physiological response (including osmolytes and ROS) will be evaluated respectively. Results are expected to yield evidences for addressing a specified mutualism between MEF and halophytes in the process co-evolution, and the underlying potential mechanisms that regualting plant stress reponse will be clarified. This would actually improve our current knowledge of adaptation of plants to abiotic stress, and pave a novel avenue towards exploitation of fungal inoculants applied in amelioration of plant abiotic threat.