1. The SNARE protein SYP71 expressed in vascular tissues is involved in symbiotic nitrogen fixation in Lotus japonicus nodules.
- Author
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Hakoyama T, Oi R, Hazuma K, Suga E, Adachi Y, Kobayashi M, Akai R, Sato S, Fukai E, Tabata S, Shibata S, Wu GJ, Hase Y, Tanaka A, Kawaguchi M, Kouchi H, Umehara Y, and Suganuma N
- Subjects
- Chromosome Mapping, Cloning, Molecular, Crosses, Genetic, Gene Expression Regulation, Plant, Genes, Plant, Genetic Complementation Test, Lotus genetics, Lotus microbiology, Mesorhizobium growth & development, Microscopy, Electron, Transmission, Mutagenesis, Phylogeny, Plant Proteins genetics, Plant Proteins metabolism, Plant Shoots genetics, Plant Shoots metabolism, Plant Vascular Bundle genetics, Plants, Genetically Modified genetics, Plants, Genetically Modified metabolism, Plants, Genetically Modified microbiology, Qc-SNARE Proteins genetics, Root Nodules, Plant genetics, Root Nodules, Plant metabolism, Root Nodules, Plant microbiology, Lotus metabolism, Nitrogen Fixation, Plant Vascular Bundle metabolism, Qc-SNARE Proteins metabolism, Symbiosis
- Abstract
Soluble N-Ethylmaleimide Sensitive Factor Attachment Protein Receptor (SNARE) proteins are crucial for signal transduction and development in plants. Here, we investigate a Lotus japonicus symbiotic mutant defective in one of the SNARE proteins. When in symbiosis with rhizobia, the growth of the mutant was retarded compared with that of the wild-type plant. Although the mutant formed nodules, these exhibited lower nitrogen fixation activity than the wild type. The rhizobia were able to invade nodule cells, but enlarged symbiosomes were observed in the infected cells. The causal gene, designated LjSYP71 (for L. japonicus syntaxin of plants71), was identified by map-based cloning and shown to encode a Qc-SNARE protein homologous to Arabidopsis (Arabidopsis thaliana) SYP71. LjSYP71 was expressed ubiquitously in shoot, roots, and nodules, and transcripts were detected in the vascular tissues. In the mutant, no other visible defects in plant morphology were observed. Furthermore, in the presence of combined nitrogen, the mutant plant grew almost as well as the wild type. These results suggest that the vascular tissues expressing LjSYP71 play a pivotal role in symbiotic nitrogen fixation in L. japonicus nodules.
- Published
- 2012
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