NopP, a phosphorylated effector of Rhizobium sp. strain NGR234, is a major determinant of nodulation of the tropical legumes Flemingia congesta and Tephrosia vogelii
Summary Rhizobium sp. NGR234 nodulates many plants, some of which react to proteins secreted via a type three secretion system (T3SS) in a positive‐ (Flemingia congesta, Tephrosia vogelii) or negative‐ (Crotalaria juncea, Pachyrhizus tuberosus) manner. T3SSs are devices that Gram‐negative bacteria u...
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Published in | Molecular microbiology Vol. 57; no. 5; pp. 1304 - 1317 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
Oxford, UK
Blackwell Science Ltd
01.09.2005
Blackwell Science Blackwell Publishing Ltd |
Subjects | |
Online Access | Get full text |
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Summary: | Summary
Rhizobium sp. NGR234 nodulates many plants, some of which react to proteins secreted via a type three secretion system (T3SS) in a positive‐ (Flemingia congesta, Tephrosia vogelii) or negative‐ (Crotalaria juncea, Pachyrhizus tuberosus) manner. T3SSs are devices that Gram‐negative bacteria use to inject effector proteins into the cytoplasm of eukaryotic cells. The only two rhizobial T3SS effector proteins characterized to date are NopL and NopP of NGR234. NopL can be phosphorylated by plant kinases and we show this to be true for NopP as well. Mutation of nopP leads to a dramatic reduction in nodule numbers on F. congesta and T. vogelii. Concomitant mutation of nopL and nopP further diminishes nodulation capacity to levels that, on T. vogelii, are lower than those produced by the T3SS null mutant NGRΩrhcN. We also show that the T3SS of NGR234 secretes at least one additional effector, which remains to be identified. In other words, NGR234 secretes a cocktail of effectors, some of which have positive effects on nodulation of certain plants while others are perceived negatively and block nodulation. NopL and NopP are two components of this mix that extend the ability of NGR234 to nodulate certain legumes. |
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Bibliography: | Department of Biology, Massachusetts Institute of Technology, Massachusetts Avenue, Cambridge, MA 02139‐4307, USA. Present address: Universidad Central del Caribe, School of Medicine, Department of Microbiology and Immunology, Call Box 60‐327, Bayamon, Puerto Rico 00960‐6032 ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 ObjectType-Article-1 ObjectType-Feature-2 |
ISSN: | 0950-382X 1365-2958 |
DOI: | 10.1111/j.1365-2958.2005.04768.x |