Rhizobium nodulation protein NodA is a host-specific determinant of the transfer of fatty acids in Nod factor biosynthesis |
| |
Authors: | T Ritsema A H M Wijfjes B J J Lugtenberg and H P Spaink |
| |
Institution: | (1) Clusius Laboratory, Leiden University, Institute of Molecular Plant Sciences, Wassenaarseweg 64, 2333 AL Leiden, The Netherlands |
| |
Abstract: | In the biosynthesis of lipochitin oligosaccharides (LCOs) theRhizobium nodulation protein NodA plays an essential role in the transfer of an acyl chain to the chitin oligosaccharide acceptor molecule. The presence ofnodA in thenodABCIJ operon makes genetic studies difficult to interpret. In order to be able to investigate the biological and biochemical functions of NodA, we have constructed a test system in which thenodA, nodB andnodC genes are separately present on different plasmids. Efficient nodulation was only obtained ifnodC was present on a low-copy-number vector. Our results confirm the notion thatnodA ofRhizobium leguminosarum biovarviciae is essential for nodulation onVicia. Surprisingly, replacement ofR. l. bv.viciae nodA by that ofBradyrhizobium sp. ANU289 results in a nodulation-minus phenotype onVicia. Further analysis revealed that theBradyrhizobium sp. ANU289 NodA is active in the biosynthesis of LCOs, but is unable to direct the transfer of theR. l. bv.viciae nodF E-dependent multi-unsaturated fatty acid to the chitin oligosaccharide acceptor. These results lead to the conclusion that the original notion thatnodA is a commonnod gene should be revised. |
| |
Keywords: | Rhizobium Nodulation Nod factors Acyl transfer nodA |
本文献已被 SpringerLink 等数据库收录! |
|