Roles of six Hsp70 genes in virulence, cell wall integrity, antioxidant activity and multiple stress tolerance of Beauveria bassiana
Roles of six Hsp70 genes in virulence, cell wall integrity, antioxidant activity and multiple stress tolerance of Beauveria bassiana
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6个Hsp70基因在白僵菌毒力、细胞壁完整性、抗氧化活性和多重胁迫耐受性中的作用
DOI：
10.1016/j.fgb.2020.103437
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发表时间：
2020-11-01
影响因子：
3
通讯作者：
Feng, Ming-Guang
中科院分区：
文献类型：
--
作者：
Wang, Jie;Chen, Jianwen;Feng, Ming-Guang
大多数HSP70编码基因的功能在丝状真菌中仍然未知。在这里，我们展示了Beauveria Bassiana的六个HSP70同源物（HSP70A-F）的重要作用，Bassiana是一种丝状真菌昆虫病原体，是广谱真菌杀虫剂的主要来源。在系统发育中，HSP70B-E，HSP70G和HSP70H与其他八个伴侣不同，这些伴侣在模型酵母中与14个HSP70蛋白共享相同的进化枝。在B. bassiana中的14个HSP70编码基因中，有8个（HSP70G/HSP70H/SSA/SSA/SSB/SSC/KAR/SSE/SSE/SSZ）在单独的障碍中可能是由于真菌生存能力的每种物质。在没有HSP70E或HSP70F（LSH1）的情况下，生长和分生体的中等缺陷发生。 HSP70F的破坏导致分生孢子热量（45度C）耐受性降低了43％，毒力降低了97％，两种降低降低到HSP70A的中断突变体中降低到19-27％和18-45％分别。在没有HSP70E（33％）的情况下，分生孢子UVB耐药性降低了（25％），HSP70C（19％）或HSP70D（15％）。所有这些破坏突变体在细胞壁完整性和抗氧化活性以及对Na+，Zn-2+，Mn2+，Cu2+和/或Fe2+的细胞耐受性中均受到差异损害。仅在没有HSP70B或HSP70F的情况下，才发生了延迟的淹没培养物和有机酸分泌的降低。我们的发现表明，HSP70A-F对于B. bassiana的宿主感染和多重胁迫耐受性很重要，并且在功能上与LSH1，SSB和SSZ同源物在功能上相似，以前在某些植物性疾病的真菌中表征。
Functions of most Hsp70-coding genes remain unknown in filamentous fungi. Here, we show important roles of six Hsp70 homologs (Hsp70a-f) in Beauveria bassiana, a filamentous fungal insect pathogen that serves as a main source of wide-spectrum fungal insecticides. In phylogeny, Hsp70b-e, Hsp70g and Hsp70h are distinct from eight other partners that share the same clade with 14 Hsp70 proteins in model yeast. Among the 14 Hsp70-coding genes in B. bassiana, eight (hsp70g/hsp70h/ssa/ssb/ssc/kar/sse/ssz) were individually undeletable perhaps due to an essentiality of each for the fungal viability. Moderate defects in growth and conidiation occurred in the absence of hsp70e or hsp70f (lsh1). The disruption of hsp70f resulted in a reduction of 43% in conidial heat (45 degrees C) tolerance and of 97% in virulence, and the two reductions decreased to 19-27% and 18-45% in the disruption mutants of hsp70a to hsp70d respectively. Conidial UVB resistance decreased more in the absence of hsp70e (33%) than of hsp70f (25%), hsp70c (19%) or hsp70d (15%). All of these disruption mutants were differentially compromised in both cell wall integrity and antioxidant activity and also in cellular tolerance to Na+, Zn-2+, Mn2+, Cu2+ and/or Fe2+. Delayed acidification of submerged cultures and reduced secretion of organic acids occurred only in the absence of hsp70b or hsp70f. Our findings indicate that hsp70a-f are important for both host infection and multiple stress tolerance of B. bassiana, and functionally similar to or beyond the lsh1, ssb and ssz homologs characterized previously in some plant-pathogenic fungi.