调控水稻类病斑细胞死亡及抗病应答的色氨酸代谢链的研究

色氨酸代谢途径对植物生长发育、逆境胁迫响应及抗病应答等均具有重要的调控作用，但其作用机制的许多环节仍有待阐明。在前期研究中，本课题组通过图位克隆首次发现，调控色氨酸生物合成第一步反应的关键基因OASA2的功能缺失，导致水稻产生类病斑细胞死亡。本项目将进一步详细研究OASA2的生物学功能，解析其调控水稻色氨酸代谢、水稻类病斑细胞死亡及抗病应答的机制。同时将应用基因编辑CRISPR-Cas9定点敲除技术或RNAi抑制技术，研究从分枝酸→色氨酸→血清素整个代谢链各个关键代谢酶基因的功能，明确调控水稻类病斑细胞死亡及抗病应答的色氨酸代谢途径功能节点。项目实施将促进对水稻细胞死亡及抗病应答机制及其分子作用网络的理解，具有重要理论意义。

Tryptophan metabolic pathway plays an important role in regulating plant development, abiotic stress responses, and pathogen defense responses. However, many details of the molecular mechanisms remain to be elucidated. In preliminary works, we identified a rice mutant in which an OASA2 gene was defective, resulting in lesion mimic cell death phenotype. OASA2 is a gene coding for the α-subunit of a key enzyme anthranilate synthase for the first step in the biosynthesis of tryptophan. In this project, we propose to detailed study functions of OASA2 in regulating tryptophan metabolism, lesion mimic cell death, and defense responses in rice. We will use CRISPR-Cas9 gene editing or RNAi suppression technology to further characterize the functions of genes of key enzymes in the Chorismate→Tryptophan→Serotonin pathway in regulating cell death and defense response in rice. Findings from this project will reveal new functional nodes in tryptophan metabolic pathway, which will contribute to understand the mechanisms undelying cell death and defense responses in rice.