杉木是我国南方重要的造林树种，而连作障碍会导致林地产量下降，自毒作用是导致产量下降的一个主要因素。目前自毒胁迫的应答机理还不清楚，因此研究自毒作用不仅对理解连作障碍具有理论价值，而且对提高林地产量至关重要。可变剪接与microRNA作为重要的转录后调控，在植物对外界胁迫应答方面扮演着重要的角色。因此本项目以杉木产量提高需求为导向，重点探索自毒胁迫下二者相互调控网络：1）可变剪接对miRNA前体序列的调控；2）可变剪接对miRNA合成基因、降解基因和功能基因的调控；3）可变剪接对miRNA靶标位点的调控；4）miRNA反过来对拼接因子的调控。本研究将综合运用多学科交叉，解析自毒物质处理前后可变剪接与microRNA之间相互调控网络的变化。以期筛选出这个相互调控网络中与自毒作用密切相关的关键基因。在阐明转录后调控网络的同时，也能为解决南方杉木林连作障碍和提高林地产量提供重要的理论依据。

Chinese fir is an important afforestation tree species in southern China. Continuous cropping will cause decline on woodland production. Autotoxicity is a major factor for declining production. However, the molecular regulation mechanism upon autotoxicity stress is unclear at present. The study of autotoxicity in Chinese fir can provide not only theoretical value about cropping obstacles, but crucial application on improving land productivity. Alternative splicing and microRNA were two important post-transcriptional regulations and plays an important role in response to the stress responses from outside world. Therefore, this project will focus on enhancing Chinese fir production by exploring mutual regulation of alternative splicing and microRNA network upon autotoxicity stress. It included four aspects: 1) alternative splicing of the precursor miRNA sequences; 2) alternative splicing of miRNA synthesis, degradation and function gene; 3) alternative splicing of miRNA target sites; 4) miRNA regulation splicing factor. In this study, bioinformatics and molecular biology will be integrated to investigate the regulation of alternative splicing and miRNA upon autotoxicity stress to obtain important genes that are closely related in the mutual regulation networks upon autotoxicity stress. This item not only elucidates the transcriptional regulatory network, but also provied important theoretical basis for solving cropping obstacles and improving woodland production for the southern Chinese fir.