as a Novel Pathogenic Gene of From in Mycelial Growth, Conidiation, and the Invasive Structures Development.

The rubber tree () is a tropical perennial crop for the primary source of natural rubber. from ( Hb) and from ( Hb) are the causal agents of rubber tree anthracnose and lead to serious loss of natural rubber production. Inoculation tests showed that Hb possessed higher pathogenicity than Hb to the rubber tree. Genomic analysis revealed that an unknown gene, named (a Novel Pathogenic Gene 1), was presented in the genome of Hb but not identified in Hb. was predicted to encode a small secretory protein without any conserved domain. To investigate the functions of in Hb and in Hb, the gene deletion and overexpression mutants were generated. The phenotype analysis showed that deletion of led to changed conidia morphology, decreased mycelial growth, conidiation, conidia germination rate, appressorium formation rate, and pathogenicity of Hb to the rubber tree. Meanwhile, heterogeneous expression of in Hb significantly changed the conidia morphology and improved the mycelial growth rate, conidiation, conidia germination rate, appressorium formation rate, and the pathogenicity of Hb to the rubber tree. Consistently, increased the expression level of and in Hb. These data suggested that contributed to mycelial growth, conidiation, the development of invasive structures, and the pathogenicity of to the rubber tree, which might be related to the modulation of CaCRZ1 and mitogen-activated protein kinase CMK1. Our results provided new insight into in regulating growth and pathogenicity of the spp.