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Early legume responses to inoculation with Rhizobium sp. NGR234

2006; Elsevier BV; Volume: 164; Issue: 6 Linguagem: Inglês

10.1016/j.jplph.2006.04.013

1618-1328

Nawal M. Boukli, E. Sunderasan, Alexander V. Bartsev, D Hochstrasser, Xavier Perret, Anthony J. Bjourson, Andréa Krause, W. J. Broughton,

Agronomic Practices and Intercropping Systems

Interactions between legumes and rhizobia are controlled by the sequential exchange of symbiotic signals. Two different techniques, 2D-PAGE electrophoresis and differential display were used to study the effects of rhizobial signals on legume development. Application of variously substituted lipo-oligo-saccharidic Nod-factors to roots of Vigna unguiculata resulted in changes in the phosphorylation patterns of microsomal proteins. Reliable amino-acid sequences were obtained for one Nod-factor enhanced protein which was highly homologous to the 57-kDa subunit from Arabidopsis thaliana vacuolar membrane H+-ATPase. Immuno-blotting techniques demonstrated that Nod-factors cause rapid and massive increases of this enzyme in treated roots, suggesting that H+-ATPases play symbiotic roles. Concomitantly, we used differential display (DD) techniques on mRNA isolated from root-hairs to analyse early root responses to NGR234. Significant matches of several DD clones to known sequences were found. Clone D2.62 was homologous to a multitude of receptor kinases including S receptor-like kinases of A. thaliana and clone D4.1 showed similarities to Lotus japonicus phosphatidylinositol transfer-like protein III and late nodulin 16. Independent confirmatory analyses of these differentially expressed clones indicated expression at very low levels.