AUTHOR=Lv Zhiyuan , He Ziwen , Hao Lijuan , Kang Xin , Ma Bi , Li Hongshun , Luo Yiwei , Yuan Jianglian , He Ningjia 

TITLE=Genome Sequencing Analysis of Scleromitrula shiraiana, a Causal Agent of Mulberry Sclerotial Disease With Narrow Host Range

JOURNAL=Frontiers in Microbiology

VOLUME=11

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2020.603927

DOI=10.3389/fmicb.2020.603927

ISSN=1664-302X

ABSTRACT=<p><italic>Scleromitrula shiraiana</italic> is a necrotrophic fungus with a narrow host range, and is one of the main causal pathogens of mulberry sclerotial disease. However, its molecular mechanisms and pathogenesis are unclear. Here, we report a 39.0 Mb high-quality genome sequence for <italic>S. shiraiana</italic> strain SX-001. The <italic>S. shiraiana</italic> genome contains 11,327 protein-coding genes. The number of genes and genome size of <italic>S. shiraiana</italic> are similar to most other Ascomycetes. The cross-similarities and differences of <italic>S. shiraiana</italic> with the closely related <italic>Sclerotinia sclerotiorum</italic> and <italic>Botrytis cinerea</italic> indicated that <italic>S. shiraiana</italic> differentiated earlier from their common ancestor. A comparative genomic analysis showed that <italic>S. shiraiana</italic> has fewer genes encoding cell wall-degrading enzymes (CWDEs) and effector proteins than that of <italic>S. sclerotiorum</italic> and <italic>B. cinerea</italic>, as well as many other Ascomycetes. This is probably a key factor in the weaker aggressiveness of <italic>S. shiraiana</italic> to other plants. <italic>S. shiraiana</italic> has many species-specific genes encoding secondary metabolism core enzymes. The diversity of secondary metabolites may be related to the adaptation of these pathogens to specific ecological niches. However, melanin and oxalic acid are conserved metabolites among many <italic>Sclerotiniaceae</italic> fungi, and may be essential for survival and infection. Our results provide insights into the narrow host range of <italic>S. shiraiana</italic> and its adaptation to mulberries.</p>