INRA, UR1290 BIOGER CPP, F-78850 Thiverval-Grignon, France.
Fungal Genet Biol. 2011 Apr;48(4):377-87. doi: 10.1016/j.fgb.2010.12.004. Epub 2010 Dec 19.
Mitogen activated protein kinase (MAPK) signal transduction pathways are ubiquitous among eukaryotic organisms with evolutionary conserved modules. Although generally classified as osmotic and cell wall integrity pathways, functional divergences have been observed for HOG1- and SLT2-related MAPK pathways. Here we show that the osmotic signal transduction cascade is involved in cell wall integrity in the phytopathogenic ascomycete Botrytis cinerea. The deletion mutants of the upstream histidine kinase Bos1 and of the MAPK Sak1 showed modified tolerance to cell wall degrading enzymes and cell wall interfering agents, as well as increased staining of β1-3 glucan and chitin compared to the wild-type. The Sak1 MAPK was phosphorylated upon cell wall challenging. Sak1 interfered with the phosphorylation status of the SLT2 type MAPK Bmp3 hinting to cross talk between both MAPK pathways. All signal transduction components interfered with the expression of melanin biosynthesis genes in dark and bright, suggesting a coordinated control of melanin biosynthesis.
丝裂原活化蛋白激酶(MAPK)信号转导途径在真核生物中普遍存在,具有进化保守的模块。虽然一般被分类为渗透和细胞壁完整性途径,但HOG1 和 SLT2 相关的 MAPK 途径已经观察到功能上的分歧。在这里,我们表明渗透信号转导级联参与了植物病原子囊菌 Botrytis cinerea 的细胞壁完整性。上游组氨酸激酶 Bos1 和 MAPK Sak1 的缺失突变体对细胞壁降解酶和细胞壁干扰剂的耐受性发生了改变,与野生型相比,β1-3 葡聚糖和几丁质的染色增加。细胞壁受到挑战时,Sak1 MAPK 被磷酸化。Sak1 干扰了 SLT2 型 MAPK Bmp3 的磷酸化状态,暗示这两种 MAPK 途径之间存在串扰。所有信号转导成分都干扰了黑色素生物合成基因在黑暗和明亮中的表达,表明黑色素生物合成的协调控制。