High-Affinity Nod Factor Binding Site from Phaseolus vulgaris Cell Suspension Cultures

Abstract

The lipo-chitooligosaccharidic Nod factors produced by rhizobia are key molecules in the establishment of symbiosis with legumes and probably are recognized by the host plant via specific receptors. Here, we report on the presence of a binding site in cell cultures of Phaseolus vulgaris displaying a high affinity for Nod factors from Rhizobium tropici (NodRt-V) (Me, S, C18:1), a symbiont of this legume. The binding site shares common properties with NFBS2, a Nod-factor binding site previously characterised in Medicago varia, in terms of affinity, preferential plasma-membrane location, and sensitivity to proteases and lysine reactive reagents. However, the bean site poorly recognizes the Nod factors produced by Sinorhizobium meliloti, the symbiont of Medicago. The study of selectivity toward the Nod factors reveals that the length and degree of unsaturation of the acyl chain and the length of the oligosaccharidic moiety are important determinants of high affinity binding to the bean site; whereas, the N-methyl and O-sulfuryl groups play a minor role. Thus, the common characteristics of P. vulgaris and M. varia Nod-factor binding sites suggest that they probably correspond to structurally related proteins, but their different selectivity suggests that they may be involved in a differential perception system for Nod factors in legumes.

Chitooligosaccharide sensing and downstream signaling: contrasted outcomes in pathogenic and beneficial plant–microbe interactions

“…Other classes of NF receptors may exist and several NF-binding sites have been identiWed in M. truncatula (Bono et al 1995;Gressent et al 1999;Hogg et al 2006) and Phaseolus vulgaris (Gressent et al 2002). In addition, a NF-binding protein called DbLNP (Dolichos biXorus Lectin Nucleotide Phosphohydrolase) has been characterized (Etzler et al 1999).…”

The NFP locus of Medicago truncatula controls an early step of Nod factor signal transduction upstream of a rapid calcium flux and root hair deformation

“…Using a biochemical approach, several proteins have been identified and it has been proposed that they are implicated in NF perception. These include NF binding sites and a lectin nucleotide phosphohydrolase that binds NFs and has an apyrase activity (Cullimore et al ., 2001; Gressent et al ., 2002). In the model legume Medicago truncatula , a genetic approach aimed at identifying genes involved in NF signal perception and transduction has been adopted (Catoira et al ., 2000).…”

Characterization of Four Lectin-Like Receptor Kinases Expressed in Roots of Medicago truncatula. Structure, Location, Regulation of Expression, and Potential Role in the Symbiosis with Sinorhizobium meliloti

“…Using a biochemical approach, two different binding sites for these molecules have been characterized in Medicago spp. (Nod-factor binding sites 1 and 2, referred to as NFBS1 and NFBS2, respectively), but their role in nodulation is not clear (Bono et al, 1995;Gressent et al, 1999Gressent et al, , 2002. A genetic approach has led recently to the cloning of a receptor kinase, with a novel extracellular domain, important for Nod factor responses (Endre et al, 2002;Stracke et al, 2002), but its dual role in establishment of a symbiosis with mycorrhizal fungi suggests that it may not be involved directly in Nod factor binding (Kistner and Parniske, 2002).…”