College of Life Sciences, Zhejiang Normal University, Jinhua 321004, China.
Int J Mol Sci. 2024 Feb 3;25(3):1874. doi: 10.3390/ijms25031874.
Calcium (Ca) is a versatile intracellular second messenger that regulates several signaling pathways involved in growth, development, stress tolerance, and immune response in plants. Autoinhibited Ca-ATPases (ACAs) play an important role in the regulation of cellular Ca homeostasis. Here, we systematically analyzed the putative OsACA family members in rice, and according to the phylogenetic tree of OsACAs, OsACA9 was clustered into a separated branch in which its homologous gene in was reported to be involved in defense response. When the gene was knocked out by CRISPR/Cas9, significant accumulation of reactive oxygen species (ROS) was detected in the mutant lines. Meanwhile, the knock out lines showed enhanced disease resistance to both rice bacterial blight (BB) and bacterial leaf streak (BLS). In addition, compared to the wild-type (WT), the mutant lines displayed an early leaf senescence phenotype, and the agronomy traits of their plant height, panicle length, and grain yield were significantly decreased. Transcriptome analysis by RNA-Seq showed that the differentially expressed genes (DEGs) between WT and the mutant were mainly enriched in basal immune pathways and antibacterial metabolite synthesis pathways. Among them, multiple genes related to rice disease resistance, () and () genes were upregulated. Our results suggest that the Ca-ATPase OsACA9 may trigger oxidative burst in response to various pathogens and synergically regulate disease resistance and leaf senescence in rice.
钙（Ca）是一种多功能的细胞内第二信使，可调节植物生长、发育、应激耐受和免疫反应等多种信号通路。自动抑制的 Ca-ATPases（ACAs）在调节细胞内 Ca 稳态方面发挥着重要作用。在这里，我们系统地分析了水稻中假定的 OsACA 家族成员，根据 OsACAs 的系统发育树，OsACA9 聚类到一个分离的分支中，其在 中的同源基因被报道参与防御反应。当使用 CRISPR/Cas9 敲除 基因时，在突变体系中检测到活性氧（ROS）的显著积累。同时， 基因敲除系对水稻细菌性条斑病（BB）和细菌性叶斑病（BLS）表现出增强的抗病性。此外，与野生型（WT）相比，突变体系表现出早期叶片衰老表型，其株高、穗长和籽粒产量等农艺性状显著降低。通过 RNA-Seq 进行的转录组分析表明，WT 和 突变体之间的差异表达基因（DEGs）主要富集在基础免疫途径和抗菌代谢物合成途径中。其中，与水稻抗病性相关的多个基因（、和 基因）上调表达。我们的结果表明，Ca-ATPase OsACA9 可能会针对各种病原体引发氧化爆发，并协同调节水稻的抗病性和叶片衰老。
