College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China.
Hangzhou Academy of Agricultural Sciences, Hangzhou 310024, China.
Res Microbiol. 2022 Oct-Dec;173(8):103970. doi: 10.1016/j.resmic.2022.103970. Epub 2022 Jul 19.
Penicillium digitatum is the most common cause of postharvest decay in citrus fruits around the world. Previous studies revealed that the bZIP gene family plays crucial roles in development, stress adaptation, and pathogenicity in fungi. However, little is known about the bZIP genes in P. digitatum. In this study, we systematically identified the bZIP family in 23 Penicillium species and analyzed their evolutionary relationships. We found that gene loss and gene duplication shaped the evolution of the Penicillium bZIP family. P. digitatum experienced 3 bZIP gene loss events, but with no gene duplication. We subsequently characterized the biological functions of one important member, PdatfA in P. digitatum by constructing the deletion mutant. Results showed that ΔPdatfA exhibited a moderate growth defect, reduced pigmentation, and slightly increased resistance to fungicides iprodione and fludioxonil. However, ΔPdatfA displayed similar rot symptoms to that of the wild-type. The ΔPdatfA mycelia were not affected in response to oxidative stress while its conidia showed enhanced resistance due to the upregulation of catalases. Our results provide new insights into the evolution and functions of the bZIP gene family in Penicillium.
青霉属是世界范围内柑橘果实采后腐烂的最主要原因。先前的研究表明，bZIP 基因家族在真菌的发育、应激适应和致病性中起着至关重要的作用。然而，关于青霉属中的 bZIP 基因知之甚少。在这项研究中，我们系统地鉴定了 23 种青霉属中的 bZIP 家族，并分析了它们的进化关系。我们发现基因丢失和基因复制塑造了青霉属 bZIP 家族的进化。青霉属经历了 3 次 bZIP 基因丢失事件，但没有基因复制。随后，我们通过构建缺失突变体来表征青霉属中一个重要成员 PdatfA 的生物学功能。结果表明，ΔPdatfA 表现出中等程度的生长缺陷、色素沉着减少和对杀真菌剂异菌脲和氟啶胺的抗性略有增加。然而，ΔPdatfA 表现出与野生型相似的腐烂症状。ΔPdatfA 的菌丝体在应对氧化应激时不受影响，但其分生孢子由于过氧化氢酶的上调而表现出增强的抗性。我们的研究结果为青霉属 bZIP 基因家族的进化和功能提供了新的见解。
