Rhizobium cellulase CelC2 is essential for primary symbiotic infection of legume host roots

• DOI: 10.1073/pnas.0802547105
• Publication Date: 2008-05-06T00:53:52Z
• Authors: M. Robledo; J. I. Jiménez-Zurdo; E. Velázquez; M. E. Trujillo; J. L. Zurdo-Piñeiro; M. H. Ramírez-Bahena; B. Ramos; J. M. Díaz-Mínguez; F. Dazzo; E. Martínez-Molina; P. F. Mateos
• Keywords: Root hair; Rhizobium leguminosarum; Nod factor

The rhizobia-legume, root-nodule symbiosis provides the most efficient source of biologically fixed ammonia fertilizer for agricultural crops. Its development involves pathways specificity, infectivity, and effectivity resulting from expressed traits bacterium host plant. A key event infection process required this is a highly localized, complete erosion plant cell wall through which bacterial symbiont penetrates to establish nitrogen-fixing, intracellular endosymbiotic state within host. This degradation must be delicately balanced avoid lysis destruction cell. Here, we describe purification, biochemical characterization, molecular genetic analysis, biological activity, symbiotic function cell-bound cellulase (CelC2) enzyme Rhizobium leguminosarum bv. trifolii, clover-nodulating endosymbiont. purified can erode noncrystalline tip white clover root hair wall, making localized hole sufficient size allow wild-type microsymbiont penetration. CelC2 not active on hairs nonhost legume alfalfa. Microscopy analysis phenotypes ANU843 wild type knockout mutant derivative revealed that fulfils an essential role in primary canonical nitrogen-fixing R. trifolii-white symbiosis.