柑橘褐斑病是柑橘上的重要病害，ACT毒素是其致病性的重要决定因子。前期研究发现转录因子ACTR在ACT毒素产生和致病具有关键作用，但其具体调控机制尚不清楚。本项目基于已构建的ACTR基因缺失突变体，构建带ACTR-GFP融合蛋白的回补突变体，观察突变体和野生型表型差异，结合ACTR基因的时空表达模式和细胞定位，确定ACTR的生物学功能。在此基础上，采用RNA-Seq获得ACTR突变体中差异表达基因，结合qRT-PCR验证和生物信息学分析，筛选ACTR调控的靶基因，并利用ChIP-qPCR技术验证靶基因启动子区域的序列，再通过靶基因敲除和功能验证，以及凝胶迁移实验验证，综合确定ACTR互作基因以及调控ACT毒素合成的作用机理，本研究可为进一步明确ACT毒素合成的调控机制奠定基础，不仅有助于拓展对真菌次生代谢调控规律的认识，还可为后期病原菌与寄主植物互作研究提供科学依据。

Alternaria brown spot is an important disease on citrus, and the ACT toxin produced by the pathogen Alternaria alternata tangerine pathotype is an important determinant of its pathogenicity. This project is based on the constructed ACTR gene deletion mutant, constructing a complemented mutant with the ACTR-GFP fusion protein, observing the difference between the mutant and wild-type phenotype, combining the expression pattern and cell positioning of the ACTR gene to determine the biology of ACTR Features. On this basis, RNA-Seq was used to obtain differentially expressed genes in ACTR mutants, combined with qRT-PCR verification and bioinformatics analysis, to screen target genes regulated by ACTR, and to use ChIP-qPCR technology to verify the sequence of the target gene promoter region. Through target gene knockout and functional verification, as well as gel migration experiment verification, can determine the ACTR interaction gene and the mechanism of regulation of ACT toxin synthesis. This study can provide the basis of the regulatory mechanism of ACT toxin synthesis, which does not only deepen the understanding of the pathogenic mechanism of toxin production but also expands the understanding of the regulation of secondary metabolic regulation of fungi, and provides a scientific basis for the study of the interaction between pathogens and host plants in future.