Type IV Effector Proteins Involved in the Medicago-Sinorhizobium Symbiosis
| Autor: | Michael J. Sadowsky, Chan Lan Chun, Matthew S. Nelson |
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| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Genotype Physiology 030106 microbiology Arabidopsis Sinorhizobium Synteny 03 medical and health sciences Bacterial Proteins Symbiosis Medicago truncatula Luteolin Bacterial Secretion Systems Gene Genetics Sinorhizobium meliloti Medicago biology Effector Reproducibility of Results food and beverages General Medicine Agrobacterium tumefaciens biochemical phenomena metabolism and nutrition biology.organism_classification Up-Regulation Phenotype 030104 developmental biology Genes Bacterial Root Nodules Plant Agronomy and Crop Science Gene Deletion |
| Zdroj: | Molecular Plant-Microbe Interactions®. 30:28-34 |
| ISSN: | 1943-7706 0894-0282 |
| Popis: | In this study, we investigated genetic elements of the type IV secretion system (T4SS) found in Sinorhizobium spp. and the role they play in symbiosis. Sinorhizobium meliloti and S. medicae each contain a putative T4SS similar to that used by Agrobacterium tumefaciens during pathogenesis. The Cre reporter assay for translocation system was used to validate potential effector proteins. Both S. meliloti and S. medicae contained the effector protein TfeA, which was translocated into the host plant. Sequence analysis revealed the presence of a nod box involved in transcriptional activation of symbiosis-related genes, upstream of the transcriptional regulator (virG) in the Sinorhizobium T4SS. Replicate quantitative reverse transcription-polymerase chain reaction analyses indicated that luteolin, released by roots and seeds of Medicago truncatula, upregulated transcription of tfeA and virG. Mutations in the T4SS apparatus or tfeA alone resulted in reduced numbers of nodules formed on M. truncatula genotypes. In addition, S. meliloti KH46c, which contains a deletion in the T4SS, was less competitive for nodule formation when coinoculated with an equal number of cells of the wild-type strain. To our knowledge, TfeA is the first T4SS effector protein identified in Sinorhizobium spp. Our results indicate that Sinorhizobium i) uses a T4SS during initiation of symbiosis with Medicago spp., and ii) alters Medicago cells in planta during symbiosis. This study also offers additional bioinformatic evidence that several different rhizobial species may use the T4SS in symbiosis with other legumes. |
| Databáze: | OpenAIRE |
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