Liang Chen, Zhang Bei, Zhou Yun, Yin Hongyan, An Bang, Lin Daozhe, He Chaozu, Luo Hongli
Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresource, College of Tropical Crops, Hainan University, Haikou, China.
Front Microbiol. 2021 Mar 8;12:629387. doi: 10.3389/fmicb.2021.629387. eCollection 2021.
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.
橡胶树（）是一种热带多年生作物，是天然橡胶的主要来源。来自（Hb）和来自（Hb）的是橡胶树炭疽病的病原体，会导致天然橡胶产量严重损失。接种试验表明，Hb对橡胶树的致病性高于Hb。基因组分析显示，在Hb基因组中存在一个名为（新型致病基因1）的未知基因，而在Hb中未鉴定到。预测其编码一种没有任何保守结构域的小分泌蛋白。为了研究在Hb和Hb中的功能，构建了基因缺失和过表达突变体。表型分析表明，的缺失导致分生孢子形态改变、菌丝生长、产孢、分生孢子萌发率、附着胞形成率以及Hb对橡胶树的致病性降低。同时，在Hb中异源表达显著改变了分生孢子形态，提高了菌丝生长速率、产孢、分生孢子萌发率、附着胞形成率以及Hb对橡胶树的致病性。一致地，增加了Hb中和的表达水平。这些数据表明，对菌丝生长、产孢、侵入结构的发育以及对橡胶树的致病性有贡献，这可能与CaCRZ1和丝裂原活化蛋白激酶CMK1的调节有关。我们的结果为在调节 spp.的生长和致病性方面提供了新的见解。
