Reduction of Aspergillus niger Virulence in Apple Fruits by Deletion of the Catalase Gene cpeB

• Published in: Journal of agricultural and food chemistry 2018-05, Vol.66 (21), p.5401-5409
• Main Authors: Zhang, Meng-Ke, Tang, Jun, Huang, Zhong-Qin, Hu, Kang-Di, Li, Yan-Hong, Han, Zhuo, Chen, Xiao-Yan, Hu, Lan-Ying, Yao, Gai-Fang, Zhang, Hua
• Format: Article
• Language: English
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/acs.jafc.8b01841

Aspergillus niger, a common saprophytic fungus, causes rot in many fruits. We studied the role of a putative catalase-peroxidase-encoding gene, cpeB, in oxidative stress and virulence in fruit. The cpeB gene was deleted in A. niger by homologous recombination, and the ΔcpeB mutant showed decreased CAT activity compared with that of the wild type. The cpeB gene deletion caused increased sensitivity to H2O2 stress, and spore germination was significantly reduced; in addition, the reactive-oxygen-species (ROS) metabolites superoxide anions (·O2 –), hydrogen peroxide (H2O2), and malondialdehyde (MDA) accumulated in the ΔcpeB mutant during H2O2 stress. Furthermore, ROS metabolism in A. niger infected apples was determined, and our results showed that the ΔcpeB mutant induced an attenuated response in apple fruit during the fruit–pathogen interaction; the cpeB gene deletion significantly reduced the development of lesions, suggesting that the cpeB gene in A. niger is essential for full virulence in apples.