The noncanonical type III secretion system ofXanthomonas translucenspv.graminisis essential for forage grass infection
| Autor: | Lena Hersemann, Constanze Conradin, Fabienne Wichmann, Sonja Reinhard, Franco Widmer, Karsten Niehaus, Frank-Jörg Vorhölter, Roland Kölliker, Jochen Blom |
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| Rok vydání: | 2013 |
| Předmět: |
0106 biological sciences
2. Zero hunger 0303 health sciences biology Effector Structural gene food and beverages Soil Science Virulence Plant Science biochemical phenomena metabolism and nutrition biology.organism_classification 01 natural sciences Xanthomonas translucens Microbiology Type three secretion system 03 medical and health sciences Xanthomonas Gene cluster Agronomy and Crop Science Molecular Biology Gene 030304 developmental biology 010606 plant biology & botany |
| Zdroj: | Molecular Plant Pathology. 14:576-588 |
| ISSN: | 1464-6722 |
| Popis: | Summary Xanthomonas translucens pv. graminis (Xtg) is a gammaproteobacterium that causes bacterial wilt on a wide range of forage grasses. To gain insight into the host–pathogen interaction and to identify the virulence factors of Xtg, we compared a draft genome sequence of one isolate (Xtg29) with other Xanthomonas spp. with sequenced genomes. The type III secretion system (T3SS) encoding a protein transport system for type III effector (T3E) proteins represents one of the most important virulence factors of Xanthomonas spp. In contrast with other Xanthomonas spp. assigned to clade 1 on the basis of phylogenetic analyses, we identified an hrp (hypersensitive response and pathogenicity) gene cluster encoding T3SS components and a representative set of 35 genes encoding putative T3Es in the genome of Xtg29. The T3SS was shown to be divergent from the hrp gene clusters of other sequenced Xanthomonas spp. Xtg mutants deficient in T3SS regulating and structural genes were constructed to clarify the role of the T3SS in forage grass colonization. Italian ryegrass infection with these mutants led to significantly reduced symptoms (P < 0.05) relative to plants infected with the wild-type strain. This showed that the T3SS is required for symptom evocation. In planta multiplication of the T3SS mutants was not impaired significantly relative to the wild-type, indicating that the T3SS is not required for survival until 14 days post-infection. This study represents the first major step to understanding the bacterial colonization strategies deployed by Xtg and may assist in the identification of resistance (R) genes in forage grasses. |
| Databáze: | OpenAIRE |
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