Interplay between calcineurin and the Slt2 MAP-kinase in mediating cell wall integrity, conidiation and virulence in the insect fungal pathogen Beauveria bassiana
Interplay between calcineurin and the Slt2 MAP-kinase in mediating cell wall integrity, conidiation and virulence in the insect fungal pathogen Beauveria bassiana
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钙调神经磷酸酶和 Slt2 MAP 激酶在介导昆虫真菌病原体白僵菌细胞壁完整性、分生孢子和毒力中的相互作用
DOI：
10.1016/j.fgb.2015.08.009
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发表时间：
2015-10-01
影响因子：
3
通讯作者：
Zhang, Yongjun
中科院分区：
文献类型：
--
作者：
Huang, Shuaishuai;He, Zhangjiang;Zhang, Yongjun
球孢白僵菌是一种具有重要环境和经济价值的昆虫病原真菌，目前主要用于生物防治多种害虫。细胞壁的完整性和分生孢子是该真菌侵染昆虫能力和产生感染性繁殖体的关键参数。研究了钙调神经磷酸酶和SLt2蛋白在球孢杆菌细胞壁完整性和发育中的作用。钙调神经磷酸酶CNA1亚基或SLt2蛋白激酶的基因敲除导致对钙离子白色和高温的耐受性降低。与野生型相比，Delta cnal品系对刚果红的耐受性更强，但对渗透胁迫(氯化钠、山梨醇)更敏感，而Delta slt2品系的表型则相反。与野生型相比，Delta slt2和Delta cnal品系在细胞壁胁迫下的生长过程中细胞壁结构和组成发生了变化。德尔塔SLT2和德尔塔cNAL菌株在生长、分生孢子和活力方面都发生了显著的变化。两个突变体的细胞内ROS水平升高，分生孢子疏水性和对疏水性表面的粘附性降低，毒力也降低。在细胞壁胁迫条件下，SLT2的失活显著抑制了CN介导的磷酸酶活性，这表明这两条途径之间存在一定程度的串扰。Delta slt2和Delta cnal菌株的比较转录组图谱显示，不同的基因组的表达发生了变化，涉及细胞壁完整性、胁迫反应、分生孢子和毒力的转录本重叠。这些数据说明了球孢杆菌钙调神经磷酸酶和SLt2途径的聚合和发散的表型和靶点。(C)2015 Elsevier Inc.保留所有权利。
The entomopathogenic fungus, Beauveria bassiana, is of environmental and economic importance as an insect pathogen, currently used for the biological control of a number of pests. Cell wall integrity and conidiation are critical parameters for the ability of the fungus to infect insects and for production of the infectious propagules. The contribution of calcineurin and the Slt2 MAP kinase to cell wall integrity and development in B. bassiana was investigated. Gene knockouts of either the calcineurin CNA1 subunit or the Slt2 MAP kinase resulted in decreased tolerance to calcofluor white and high temperature. In contrast, the Delta cnal strain was more tolerant to Congo red but more sensitive to osmotic stress (NaCl, sorbitol) than the wild type, whereas the Delta slt2 strain had the opposite phenotype. Changes in cell wall structure and composition were seen in the Delta slt2 and Delta cnal strains during growth under cell wall stress as compared to the wild type. Both Delta slt2 and Delta cnal strains showed significant alterations in growth, conidiation, and viability. Elevation of intracellular ROS levels, and decreased conidial hydrophobicity and adhesion to hydrophobic surfaces, were also seen for both mutants, as well as decreased virulence. Under cell wall stress conditions, inactivation of Slt2 significantly repressed CN-mediated phosphatase activity suggesting some level of cross talk between the two pathways. Comparative transcriptome profiling of the Delta slt2 and Delta cnal strains revealed alterations in the expression of distinct gene sets, with overlap in transcripts involved in cell wall integrity, stress response, conidiation and virulence. These data illustrate convergent and divergent phenotypes and targets of the calcineurin and Slt2 pathways in B. bassiana. (C) 2015 Elsevier Inc. All rights reserved.