玉米弯孢菌叶斑病是由新月弯孢菌（Curvularia lunata）引起的一种严重病害，脱落酸、胁迫和成熟诱导蛋白（Abscisic acid-, stress-, and ripening-induced proteins, ASR）蛋白家族在植物应对多种非生物胁迫中发挥重要作用，但其在玉米抗病过程中的功能尚不明确。为探究ASR蛋白在玉米响应弯孢菌侵染中的分子机制，本研究以高感病自交系黄早四、昌7-2和高抗病自交系沈137、齐319为材料，成功克隆得到一个玉米ASR基因（aasr1）。序列分析：黄早四、昌7-2的编码序列（Coding Sequence, CDS）长度为426 bp，沈137、齐319为417 bp。在CDS区存在12处碱基突变，编码蛋白质存在5个氨基酸差异。Aasr1蛋白为亲水性酸性蛋白，无信号肽和跨膜结构，亚细胞定位实验证实Aasr1蛋白定位于细胞核，表明其可能作为转录调控因子行使功能。系统进化分析表明该蛋白与禾本科谷子亲缘关系最近。在弯孢菌侵染条件下，抗病品种沈137、齐319表现出更强烈的防御反应，其抗氧化酶系统包括过氧化物酶（Peroxidase, POD）、超氧化物歧化酶（Superoxide Dismutase, SOD）和过氧化氢酶（Catalase, CAT） 活性峰值显著高于感病品种黄早四、昌7-2，而膜脂过氧化产物丙二醛（Malondialdehyde, MDA）的积累量显著较低。实时定量聚合酶链式反应（Quantitative Real-time Polymerase Chain Reaction, qRT-PCR）分析发现，aasr1基因在抗病品种中受病原侵染诱导表达的程度显著更高，其表达模式与防御酶活性变化高度协同

Curvularia lunata leaf spot disease is a serious disease caused by Curvularia lunata. The Abscisic acid-, stress-, and ripening-induced proteins (ASR) protein family plays an important role in plants' response to various abiotic stresses, but its function in the disease resistance process of maize is still unclear. To explore the molecular mechanism of ASR proteins in maize's response to Curvularia lunata infection, this study used the highly susceptible inbred lines Huangzaosi and Chang7-2 and the highly resistant inbred lines Shen137 and Qi319 as materials and successfully cloned a maize ASR gene (aasr1). Sequence analysis: The coding sequence (CDS) length of Huangzaosi and Chang7-2 was 426 bp, and that of Shen137 and Qi319 was 417 bp. There were 12 base mutations in the CDS region, and the encoded proteins had 5 amino acid differences. The Aasr1 protein is a hydrophilic acidic protein without signal peptides or transmembrane structures. Subcellular localization experiments confirmed that the Aasr1 protein is located in the nucleus, indicating that it may function as a transcriptional regulatory factor. Phylogenetic analysis showed that this protein is most closely related to the genus Setaria of the Poaceae family. Under Curvularia lunata infection conditions, the resistant varieties Shen137 and Qi319 showed a stronger defense response. The peak activities of their antioxidant enzyme systems, including peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT), were significantly higher than those of the susceptible varieties Huangzaosi and Chang7-2, while the accumulation of malondialdehyde (MDA), a membrane lipid peroxidation product, was significantly lower. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis found that the aasr1 gene was significantly more induced by pathogen infection in the resistant varieties, and its expression pattern was highly coordinated with the changes in defense enzyme activities.

国家自然科学基金(31660395),吉林省科技厅基金(202002026JC),延边大学校企合作项目(ydhx202311)。