Li Guoqi, Liu Shaoting, Wu Lijuan, Wang Xiao, Cuan Rongrong, Zheng Yongliang, Liu Deli, Yuan Yongze
Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, China.
School of Public Administration, Central China Normal University, Wuhan 430079, China.
J Fungi (Basel). 2022 Jun 25;8(7):667. doi: 10.3390/jof8070667.
Calcium (Ca)/calmodulin-dependent protein kinases (CaMKs) act as a class of crucial elements in Ca-signal transduction pathways that regulate fungal growth, sporulation, virulence, and environmental stress tolerance. However, little is known about the function of such protein kinase in phytopathogenic species. In the present study, a new CaMK gene from the citrus pathogenic fungus , designated , was cloned and functionally characterized by gene knockout and transcriptome analysis. The open reading frame of is 1209 bp in full length, which encodes 402 amino acid residues (putative molecular weight 45.2 KD) with the highest homologous (96.3%) to the CaMK. The knockout mutant Δ showed a significant reduction in vegetative growth, conidiation, and virulence (i.e., to induce blue mold decay on citrus fruit). Δ was less sensitive to NaCl- or KCl-induced salinity stress and less resistant to mannitol-induced osmotic stress, indicating the functional involvement of in such environmental stress tolerance. In contrast, the -complemented strain ΔCOM can restore all the defective phenotypes. Transcriptome analysis revealed that knockout of down-regulated expression of the genes involved in DNA replication and repair, cell cycle, meiosis, pyrimidine and purine metabolisms, and MAPK signaling pathway. Our results suggested the critical role of in regulating multiple physical and cellular processes of citrus postharvest pathogen , including growth, conidiation, virulence, and environmental stress tolerance.
钙（Ca）/钙调蛋白依赖性蛋白激酶（CaMKs）是钙信号转导途径中的一类关键元件，可调节真菌的生长、孢子形成、毒力和环境胁迫耐受性。然而，关于这种蛋白激酶在植物致病物种中的功能却知之甚少。在本研究中，从柑橘致病真菌中克隆了一个新的CaMK基因，命名为 ，并通过基因敲除和转录组分析对其进行了功能表征。 的开放阅读框全长1209 bp，编码402个氨基酸残基（推定分子量约45.2 KD），与 CaMK的同源性最高（约96.3%）。敲除突变体Δ在营养生长、分生孢子形成和毒力方面（即诱导柑橘果实青霉腐烂）显著降低。Δ对NaCl或KCl诱导的盐胁迫不太敏感，对甘露醇诱导的渗透胁迫抗性较弱，表明 在这种环境胁迫耐受性中发挥功能作用。相反， 互补菌株ΔCOM可以恢复所有缺陷表型。转录组分析表明， 的敲除下调了参与DNA复制和修复、细胞周期、减数分裂、嘧啶和嘌呤代谢以及MAPK信号通路的基因表达。我们的结果表明 在调节柑橘采后病原菌多种生理和细胞过程中起着关键作用，包括生长、分生孢子形成、毒力和环境胁迫耐受性。
