生长素前体IBA调控锥栗外生菌根发育的机理研究

锥栗是我国南方重要的生态经济树种，外生菌根（ECM）的形成可显著提高苗木在丘陵山区的造林成活率。激素在ECM发育中起到重要的调控作用，前期研究发现生长素前体IBA影响锥栗试管苗生根及根系构型，那么IBA是否参与调控锥栗ECM发育？尚不清楚。因此，本研究以锥栗试管苗与ECM真菌共生为基础，1）利用光学显微和电子显微技术等，阐明锥栗ECM形态和细胞学特征及其ECM的发育进程；2）利用HPLC-MSn分析和免疫胶体金技术等，探明锥栗ECM发育进程中的激素分布及消长动态变化规律，并结合外源IBA处理，阐明锥栗ECM发育对IBA的响应特征； 3）利用转录组测序、生物信息学分析和原位杂交等技术，明确IBA对锥栗ECM发育关键基因表达的调控特征，从而揭示生长素前体IBA调控锥栗ECM发育的机理。研究结果可为锥栗菌根化育苗生产提供实践指导和理论基础。

Castanea henryi is an important woody grain tree species in China. The formation of ectomycorrhizal (ECM) has great potential to improve the survival rate of seedlings in the arid hilly areas in south China. Hormones play important role in the regulation of ECM develop, preliminary study found that the auxin precursor IBA could affect the test-tube seedlings rooting and root system architecture. However, there are some problems still unclear. Whether or not the IBA associated with the ECM development? And how these key genes of auxin biosynthesis and signal transduction affect the ECM development? In this proposed project, tissue culture seedlings of C. henryi and the ectomycorrhizal fungal Boletus edulis are adopted, (1) to establish in vitro co-culture system. We plan to explore the morphological and anatomical characteristics of ECM development by using optical microscopy and electron microscopy, and figure out the developmental schedule in C. henryi. (2) To explore the dynamic variation rules and distribution of endogenous hormone during the ECM development, and combined with external IBA validation test to assume that auxin precursor IBA involved in C. henryi ECM development. (3) To study how the IBA to regulate the key gene expression of C. henryi ECM by using transcriptomics RNA-seq and bioinformatics analysis，thus to elaborate the regulation mechanism of auxin precursor IBA on ECM development of C. henryi. The results of this study can provide a scientific and theoretical basis for the cultivation of high quality C. henryi mycorrhizal seedlings in production.