Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China.
Curr Genet. 2010 Dec;56(6):517-28. doi: 10.1007/s00294-010-0319-x. Epub 2010 Sep 17.
A two-component signal transduction system is a common mechanism for environmental sensing in bacteria. The functions of the two-component molecules have been also well characterized in the lower eukaryotic fungi in recent years. In Saccharomyces cerevisiae, the histidine kinase Sln1p is a major component of the two-component signaling pathways and a key regulator of the osmolarity response. To determine the function of MoSLN1, a Sln1 homolog of Magnaporthe oryzae, we cloned the MoSLN1 gene and generated specific mutants using gene knock-out strategy. Disruption of MoSLN1 resulted in hypersensitivity to various stresses, reduced sensitivity to cell wall perturbing agent Calcofluor white, and loss of pathogenicity, mainly due to a penetration defect. Additionally, we showed that MoSLN1 is involved in oxidative signaling through modulation of intra- and extracellular peroxidase activities. These results indicate that MoSLN1 functions as a pathogenicity factor that plays a role in responses to osmotic stress, the cell wall integrity, and the activity of peroxidases.
双组分信号转导系统是细菌环境感应的常见机制。近年来，在较低等真核真菌中，双组分分子的功能也得到了很好的表征。在酿酒酵母中，组氨酸激酶 Sln1p 是双组分信号通路的主要组成部分，也是渗透压响应的关键调节剂。为了确定 Magnaporthe oryzae 的 Sln1 同源物 MoSLN1 的功能，我们克隆了 MoSLN1 基因，并利用基因敲除策略生成了特定的突变体。MoSLN1 的破坏导致对各种应激的敏感性增加，对细胞壁扰动剂 Calcofluor white 的敏感性降低，以及致病性丧失，主要是由于穿透缺陷。此外，我们表明 MoSLN1 通过调节细胞内外过氧化物酶的活性参与氧化信号转导。这些结果表明，MoSLN1 作为一种致病性因子发挥作用，参与了对渗透压应激、细胞壁完整性和过氧化物酶活性的反应。
