Perception of <i>Rhizobium</i> nodulation factors by tomato cells and inactivation by root chitinases

Article Article scientifique Article Perception of <i>Rhizobium</i> nodulation factors by tomato cells and inactivation by root chitinases eng 1994 author Staehelin Christian 133554 author Granado José author Muller Joachim Andréas 53541 author Wiemken Andres author Mellor Robert B. author Felix Georg author Regenass Martin 519221 author Broughton William John 22724 author Boller Thomas Peter 757674 2196-2200 10.1073/pnas.91.6.2196 8134372 0027-8424 http://www.pnas.org/cgi/doi/10.1073/pnas.91.6.2196 The bacterial genera Rhizobium and Bradyrhizobium, nitrogen-fixing symbionts of legumes, secrete specific lipo-chitooligosaccharides that induce the formation of nodules on their host plants. When preparations of such nodulation-inducing factors (Nod factors) were added to suspension-cultured tomato cells, a rapid and transient alkalinization of the culture medium occurred. Lipo-oligosaccharide preparations from Rhizobium or Bradyrhizobium treated with flavonoids, known inducers of Nod factor synthesis, were up to 100 times more potent in inducing alkalinization than the ones from untreated bacteria. The activity was absent from preparations of the mutant strain Rhizobium sp. NGR234 delta nodABC, unable to produce any Nod factors. Preparations of Nod factors from various bacteria as well as individual, highly purified Nod factors from Rhizobium sp. NGR(pA28) induced alkalinization in the tomato cell cultures at nanomolar concentrations. This demonstrates that Nod factors can be perceived by tomato, a nonhost of rhizobia. Using the alkalinization response as a sensitive bioassay, Nod factors were found to be inactivated by plant chitinases. Root chitinases purified from different legumes differed in their potential to inactivate differently substituted Nod factors produced by Rhizobium sp. NGR(pA28). This indicates that the specificity of the bacterium-host plant interaction may be due, at least in part, to differential inactivation of Nod factors by root chitinases. Chemoperception Chito-oligosaccharides Signalling Symbiosis Dewey 580 45 Département des sciences végétales 163 false Proceedings of the National Academy of Sciences 91 6 ec3fa2e9-1e13-45c5-8b36-e293711da674 Article (Published version) Public pnas01128-0224.pdf 1092552 application/pdf OA OTHER openAccess Faculté des sciences / Section de biologie / Département des sciences végétales

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Perception of Rhizobium nodulation factors by tomato cells and inactivation by root chitinases	Proceedings of the National Academy of Sciences			1994	331	142

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Regenass, Martin