Kang In-Jeong, Kim Kyung Seok, Beattie Gwyn A, Yang Jung-Wook, Sohn Kee Hoon, Heu Sunggi, Hwang Ingyu
Division of Crop Cultivation and Environment Research, National Institute of Crop Science, Suwon 16613, Korea.
Department of Agricultural Biotechnology, Seoul National University, Seoul 08826, Korea.
Microorganisms. 2021 Sep 30;9(10):2065. doi: 10.3390/microorganisms9102065.
pv. is a major pathogen of soybean in Korea. Here, we analyzed pathogenicity genes based on a comparative genome analysis of five Korean strains and one strain from the United States, 8ra. Whereas all six strains had nearly identical profiles of carbohydrate-active enzymes, they varied in diversity and number of candidate type III secretion system effector (T3SE) genes. The five Korean strains were similar in their effectors, but differed from the 8ra strain. Across the six strains, transcription activator-like effectors (TALEs) showed diverse repeat sizes and at least six forms of the repeat variable di-residue (RVD) sequences, with differences not correlated with the origin of the strains. However, a phylogenetic tree based on the alignment of RVD sequences showed two distinct clusters with 17.5 repeats, suggesting that two distinct 17.5 RVD clusters have evolved, potentially to adapt to growth on distinct soybean cultivars. The predicted effector binding elements of the TALEs fell into six groups and were strongly overlapping in sequence, suggesting evolving target specificity of the binding domains in soybean cultivars. Our findings reveal the variability and adaptability of T3SEs in the strains and enhance our understanding of pathogenicity in soybean.
pv. 是韩国大豆的主要病原菌。在此，我们基于对五个韩国菌株和一个来自美国的菌株8ra的比较基因组分析，分析了致病基因。尽管所有六个菌株的碳水化合物活性酶谱几乎相同，但它们在候选III型分泌系统效应子（T3SE）基因的多样性和数量上有所不同。五个韩国菌株的效应子相似，但与8ra菌株不同。在这六个菌株中，转录激活样效应子（TALEs）显示出不同的重复序列大小和至少六种形式的重复可变双残基（RVD）序列，差异与菌株的来源无关。然而，基于RVD序列比对的系统发育树显示出两个具有17.5个重复序列的不同簇，表明两个不同的17.5 RVD簇已经进化，可能是为了适应在不同大豆品种上的生长。TALEs的预测效应子结合元件分为六组，序列上有很强的重叠，表明大豆品种中结合域的靶标特异性在不断进化。我们的研究结果揭示了菌株中T3SEs的变异性和适应性，并增强了我们对大豆致病性的理解。
