State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 311400, China.
Key Laboratory for Zhejiang Super Rice Research, China National Rice Research Institute, Hangzhou 311400, China.
Int J Mol Sci. 2022 Jun 29;23(13):7234. doi: 10.3390/ijms23137234.
Lesion mimic mutants (LMMs) are ideal materials for studying cell death and resistance mechanisms. Here, we identified and mapped a novel rice LMM, . The exhibits a spontaneous hypersensitive response-like cell death phenotype accompanied by excessive accumulation of reactive oxygen species (ROS) and upregulated expression of pathogenesis-related genes, as well as enhanced resistance to pv. (). Using a map-based cloning strategy, a 184,916 bp deletion on chromosome 2 that overlaps with the diterpenoid biosynthetic gene cluster was identified in . Accordingly, the content of diterpenoids decreased in . In addition, lignin, one of the physical lines of plant defense, was increased in . RNA-seq analysis showed 590 significantly differentially expressed genes (DEG) between the wild-type and , 585 of which were upregulated in . Upregulated genes in were mainly enriched in the monolignol biosynthesis branches of the phenylpropanoid biosynthesis pathway, the plant-pathogen interaction pathway and the phytoalexin-specialized diterpenoid biosynthesis pathway. Taken together, our results indicate that the diterpenoid biosynthetic gene cluster on chromosome 2 is involved in immune reprogramming, which in turn regulates cell death in rice.
病变模拟突变体（LMMs）是研究细胞死亡和抗性机制的理想材料。在这里，我们鉴定并定位了一个新的水稻 LMM， 。 表现出自发的过敏反应样细胞死亡表型，伴随着活性氧（ROS）的过度积累和病程相关基因的上调表达，以及对 pv. 的增强抗性（）。利用基于图谱的克隆策略，在 上鉴定到一个 184,916 bp 的缺失，该缺失重叠在二萜生物合成基因簇上。因此， 在 中的二萜含量降低。此外，木质素是植物防御的物理防线之一，在 中增加。RNA-seq 分析显示，在野生型 和 之间有 590 个显著差异表达基因（DEG），其中 585 个在 中上调。 在 中上调的基因主要富集在苯丙烷生物合成途径的单酚生物合成分支、植物-病原体相互作用途径和植物防御素特异性二萜生物合成途径中。总之，我们的结果表明，染色体 2 上的二萜生物合成基因簇参与免疫重编程，进而调节水稻中的细胞死亡。
