The Lmpma1 gene of Leptosphaeria maculans encodes a plasma membrane H⁺-ATPase isoform essential for pathogenicity towards oilseed rape

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• 作者：Estelle Remy ; Michel Meyer ; Franç ; oise Blaise ; Mé ; lanie Chabir ; Nelly Wolff ; Marie-Hé ; lè ; ne Balesdent ; Thierry Rouxel
• 关键词：Insertional mutagenesis ; Leptosphaeria maculans ; Pathogenicity gene ; Plasma membrane H⁺-ATPase ; Oilseed rape ; Stem canker
• 刊名：Fungal Genetics and Biology
• 出版年：2008
• 出版时间：July 2008
• 年：2008
• 卷：45
• 期：7
• 页码：1122-1134
• 全文大小：1004 K

文摘

Following Agrobacterium tumefaciens-mediated mutagenesis in Leptosphaeria maculans, we identified the mutant 210, displaying total loss of pathogenicity towards its host plant (Brassica napus). Microscopic observations showed that m210 is unable to germinate on the host leaf surface and is thus blocked at the pre-penetration stage. The pathogenicity phenotype is linked with a single T-DNA insertion into the promoter region of a typical plasma membrane H⁺-ATPase-encoding gene, termed Lmpma1, thus leading to a twofold reduction in Lmpma1 expression. Since LmPMA1 is involved in intracellular pH homeostasis, we postulate that reduction in LmPMA1 activity disturbs the electrochemical transmembrane gradient in m210, thus leading to conidia defective in turgor pressure generation on leaf surface. Whole genome survey showed that L. maculans possesses a second plasma membrane H⁺-ATPase-encoding gene, termed Lmpma2. Silencing experiments, expression analyses and phylogenetic studies allowed us to highlight the essential role assumed by the Lmpma1 isoform in L. maculans pathogenicity.