State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China.
College of Life Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
Int J Mol Sci. 2018 Nov 27;19(12):3766. doi: 10.3390/ijms19123766.
Many spotted-leaf mutants show enhanced disease resistance to multiple pathogen attacks; however, the mechanisms are largely unknown. Here, we reported a novel semi-dominant () obtained from an ethyl methane sulfonate (EMS)-induced IR64 mutant bank. developed tiny brown lesions on the leaf tip and spread down gradually to the leaf base as well as the sheath at the early heading stage. The performances of major agronomic traits such as the plant height, panicle length, number of panicles/plant, and 1000-grain weight were significantly altered in when compared to the wild-type IR64. Furthermore, exhibited a premature senescing phenotype with degeneration of nuclear acids, significantly reduced soluble protein content, increased level of malonaldehyde (MDA), and lowered activities of reactive oxygen species (ROS) scavenging enzymes. Disease evaluation indicated that showed enhanced resistance to multiple races of pv. , the causal pathogen of bacterial leaf blight in rice, with elevated expression of pathogenesis-related genes, salicylic acid (SA) signaling pathway-associated genes revealed by real-time quantitative PCR and high-throughput RNA sequencing analysis. Genetic analysis and gene mapping indicated that the lesion mimic phenotype was controlled by a novel semi-dominant nuclear gene. The mutation, tentatively termed as , was in a 110 kb region flanked by markers Indel-33 and Indel-12 in chromosome 11. Together, our data suggest that is a novel lesion mimic mutant with enhanced innate immunity and would facilitate the isolation and functional characterization of the target gene.
许多斑驳叶突变体对多种病原菌的攻击表现出增强的抗病性；然而，其机制在很大程度上尚不清楚。在这里，我们报道了一种来自乙基甲烷磺酸酯（EMS）诱导的 IR64 突变体库的新型半显性突变体 ()。在早期抽穗期， 突变体在叶片尖端形成微小的棕色病斑，并逐渐向下扩散到叶片基部和叶鞘。与野生型 IR64 相比， 突变体的主要农艺性状如株高、穗长、穗数/株和千粒重等均发生显著改变。此外， 突变体表现出过早衰老的表型，核酸降解，可溶性蛋白含量显著降低，丙二醛（MDA）水平升高，活性氧（ROS）清除酶活性降低。病害评价表明， 突变体对多种稻白叶枯病菌（ pv. ）菌株表现出增强的抗性，通过实时定量 PCR 和高通量 RNA 测序分析，表明与病程相关基因和水杨酸（SA）信号通路相关基因的表达增强。遗传分析和基因定位表明，病斑模拟表型受一个新的半显性核基因控制。该突变，暂定命名为 ，位于第 11 号染色体上标记 Indel-33 和 Indel-12 之间的 110kb 区域内。总之，我们的数据表明 是一种具有增强的先天免疫的新型病斑模拟突变体，这将有助于目标基因的分离和功能鉴定。
