Colletotrichum gloeosporioides is one of the most serious diseases that causes damage to mangoes. Laccase, a copper-containing polyphenol oxidase, has been reported in many species with different functions and activities, and fungal laccase could be closely related to mycelial growth, melanin and appressorium formation, pathogenicity, and so on. Therefore, what is the relationship between laccase and pathogenicity? Do laccase genes have different functions? In this experiment, the knockout mutant and complementary strain of Cglac13 were obtained through polyethylene glycol (PEG)-mediated protoplast transformation, which then determined the related phenotypes. The results showed that the knockout of Cglac13 significantly increased the germ tube formation, and the formation rates of appressoria significantly decreased, delaying the mycelial growth and lignin degradation and, ultimately, leading to a significant reduction in the pathogenicity in mango fruit. Furthermore, we observed that Cglac13 was involved in regulating the formation of germ tubes and appressoria, mycelial growth, lignin degradation, and pathogenicity of C. gloeosporioides. This study is the first to report that the function of laccase is related to the formation of germ tubes, and this provides new insights into the pathogenesis of laccase in C. gloeosporioides.

Mango (Mangifera indica L.) is an important economical crop in South China. In 2014, a stem-end rot disease was observed on mangoes 10 days after harvest from Sanya city（18.2° N and 106.5° E）, Ledong county（18.5° N and 109.1° E） and Lingshui county（18.5° N and 110.0° E）, Hainan province, China. Initial symptoms were dark brown small spots, quickly darkened and expanded into large spots with irregular margin and internal rotten flesh. Signs of the disease could be observed as fungal mycelium and pycnidia developing on the fruit surface. Twelve diseased fruits collected from 4 places weresurface disinfested using 75% ethanol, segments were dissected from the border between symptomatic and visually healthy peel and placed on potato dextrose agar (PDA) at 25 °C. Four representative isolates ACCC 39317, ACCC 39318, ACCC 39320, and ACCC 39321 were purified using the single spore method and submitted to the Agricultural Culture Collection of China（ACCC）. The initial color of the colonies was translucent white, e...

The filamentous fungus Colletotrichum gloeosporioides is the causative agent of one of the most serious diseases that damage plant fruit. In this study, we discovered and experimentally characterized a new gene in Colletotrichum gloeosporioides named CgloRPCYG. The CRISPR/Cas9 knockout mutant and complementary strain of CgloRPCYG were then obtained by polyethylene glycol (PEG)-mediated protoplast transformation to determine the related phenotypes. Compared with the wild-type strain and complementary mutant, the pathogenicity of the CRISPR/Cas9 knockout mutant was significantly decreased, the conidial yield was significantly reduced, and conidial germination was significantly delayed. These data indicate that CgloRPCYG contributes to pathogenicity, conidial yield, and germination in C. gloeosporioides. The successful application of the CRISPR/Cas9 system in C. gloeosporioides also confirms its utility in filamentous fungi for fundamental research and practical application. Furthermore, CgloRPCYG is a potential target gene for use in the development of plant protection technologies, such as spray-induced gene silencing, with the aim of controlling plant anthracnose disease caused by C. gloeosporioides.