The AwHog1 Transcription Factor Influences the Osmotic Stress Response, Mycelium Growth, OTA Production, and Pathogenicity in Aspergillus westerdijkiae fc-1
Author:
Wang Yufei1, Liu Fei2, Pei Jingying1, Yan Hao3, Wang Yan1ORCID
Affiliation:
1. College of Food Science and Technology, Zhejiang University of Technology, No. 18 Chaowang Road, Gongshu District, Hangzhou 310014, China 2. Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, No. 2 Yuanmingyuan West Road, Haidian District, Beijing 100193, China 3. Zhejiang Provincial Center for Disease Control and Prevention, No. 3399 Binsheng Road, Binjiang District, Hangzhou 310051, China
Abstract
Aspergillus westerdijkiae, known as the major ochratoxin A (OTA) producer, usually occurs on agricultural crops, fruits, and dry-cured meats. Microorganisms produce OTA to adapt to the high osmotic pressure environment that is generated during food processing and storage. To investigate the relationship between OTA biosynthesis and the high osmolarity glycerol (HOG) pathway, the transcription factor AwHog1 gene in A. westerdijkiae was functionally characterised by means of a loss-of-function mutant. Our findings demonstrated that the growth and OTA production of a mutant lacking AwHog1 decreased significantly and was more sensitive to high osmotic media. The ΔAwHog1 mutant displayed a lower growth rate and a 73.16% reduction in OTA production in the wheat medium compared to the wild type. After three days of culture, the growth rate of the ΔAwHog1 mutant in medium with 60 g/L NaCl and 150 g/L glucose was slowed down 19.57% and 13.21%, respectively. Additionally, the expression of OTA biosynthesis genes was significantly reduced by the deletion of the AwHog1 gene. The infection ability of the ΔAwHog1 mutant was decreased, and the scab diameter of the pear was 6% smaller than that of the wild type. These data revealed that transcription factor AwHog1 plays a key role in the osmotic response, growth, OTA production, and pathogenicity in A. westerdijkiae.
Funder
National Natural Science Foundation of China National Scholarship Fund of China Key Research and Development Projects of Zhejiang Visiting Scholar Teacher Professional Development Project
Subject
Health, Toxicology and Mutagenesis,Toxicology
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