玉米作为我国第一大粮食作物，可用于人类食品、动物饲料，工业燃料等领域，是重要的经济和粮食作物。玉米大斑病菌（Setosphaeria turcica）引发的玉米大斑病（Northern corn leaf blight， NCLB）是严重威胁玉米粮食安全的重要植物病原真菌。该病菌在侵染过程中需要借助于特殊的侵染结构-附着胞。利用膨压和物理机械力穿透寄主植物表皮，完成其侵染过程。虽然，实验室前期已经证实玉米大斑病菌在应对基因损伤胁迫时，通过激活ATR介导的S期检验点，关闭附着胞介导的侵染寄主的能力，同时促进黑色素合成进行自我保护。但是，在响应DNA损伤应激反应中是否还存在其他的调控途径尚未明确。为解析该调控过程，本研究利用DNA损伤药物羟基脲（HU）处理玉米大斑病菌分生孢子并进行转录组测序。通过对转录组数据中显著差异基因进行注释聚类分析，qPCR表达模式分析，经典分子生物学验证以及生物信息学分析，最终鉴定到一些列基因参与DNA损伤应激反应。结果显示，玉米大斑病菌在应对DNA损伤胁迫时，大量次级代谢和黑色素生物合成相关基因在附着胞形成过程中被阻断。次级代谢生物合成基因包括醇脱氢酶类、多铜氧化酶、ABC蛋白转运家族、细胞色素P450和含FAD结构域的单加氧酶等植物病原体感染有关的基因。此外，研究发现一系列细胞自噬基因在HU处理后显著上调。其中包括StATG3、StATG4、StATG5、StATG7和StATG16等细胞自噬基因。并且研究结果表明该细胞自噬调控途径受到ATR介导的S期检查点调控。因此，本研究首次提出玉米大斑病菌在应对基因损伤胁迫时，关闭附着胞侵染寄主的能力，同时激活ATR介导的S期检验点促进细胞自噬的发生，这可能是除黑色素外的另一种自我保护机制，并且该调控过程在进化过程中是保守的。

The fungal pathogen Setosphaeria turcica causes northern corn leaf blight (NCLB), which leads to considerable crop losses.  Setosphaeria turcica elaborates a specialized infection structures called appressorium for maize infection.  Previously, we demonstrated that the S. turcica triggers an S-phase checkpoint and ATR (Ataxia Telangiectasia and Rad3 related)-dependent self-protective response to DNA genotoxic insults during maize infection.  However, how the regulatory mechanism works was still largely unknown.  Here, we report a genome wide transcriptional profile analysis during appressorium formation in the present of DNA replication stress.  We performed RNA-Seq analysis to identify S. tuicica genes responsive to DNA replication stress.  In the current work, we found that appressorium-mediated maize infection by S. turcica is significantly blocked by S-phase checkpoint.  A large serial of secondary metabolite and melanin biosynthesis genes were blocked in appressorium formation of S. turcica during the replication stress.  The secondary metabolite biosynthesis genes including alcohol dehydrogenase GroES-like domain, multicopper oxidase, ABC-transporter families, cytochrome P450 and FAD-containing monooxygenase were related to plant pathogen infection.  In addition, we demonstrated that autophagy in S. turcica is up-regulated by ATR as a defense response to stress.  We identified StATG3, StATG4, StATG5, StATG7 and StATG16 genes for autophagy were induced by ATR-mediated S-phase checkpoint.  We therefore propose that in response to genotoxic stress, S. turcica utilizes ATR-dependent pathway to turn off transcription of genes governing appressorium-mediated infection, and meanwhile inducing transcription of autophagy genes likely as a mechanism of self-protection, aside from the more conservative responses in eukaryotes.