Citlali Fonseca-García1, Noreide Nava1, Miguel Lara1, Carmen Quinto2. 1. Departamento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad, Cuernavaca, Morelos, Colonia Chamilpa, Mexico. 2. Departamento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenida Universidad, Cuernavaca, Morelos, Colonia Chamilpa, Mexico. carmen.quinto@ibt.unam.mx.
Abstract
BACKGROUND: Rhizobium-legume symbiosis is a specific, coordinated interaction that results in the formation of a root nodule, where biological nitrogen fixation occurs. NADPH oxidases, or Respiratory Burst Oxidase Homologs (RBOHs) in plants, are enzymes that generate superoxide (O2 •-). Superoxide produces other reactive oxygen species (ROS); these ROS regulate different stages of mutualistic interactions. For example, changes in ROS levels are thought to induce ROS scavenging, cell wall remodeling, and changes in phytohormone homeostasis during symbiotic interactions. In common bean (Phaseolus vulgaris), PvRbohB plays a key role in the early stages of nodulation. RESULTS: In this study, to explore the role of PvRbohB in root nodule symbiosis, we analyzed transcriptomic data from the roots of common bean under control conditions (transgenic roots without construction) and roots with downregulated expression of PvRbohB (by RNA interference) non-inoculated and inoculated with R. tropici. Our results suggest that ROS produced by PvRBOHB play a central role in infection thread formation and nodule organogenesis through crosstalk with flavonoids, carbon metabolism, cell cycle regulation, and the plant hormones auxin and cytokinin during the early stages of this process. CONCLUSIONS: Our findings provide important insight into the multiple roles of ROS in regulating rhizobia-legume symbiosis.
BACKGROUND:Rhizobium-legume symbiosis is a specific, coordinated interaction that results in the formation of a root nodule, where biological nitrogen fixation occurs. NADPH oxidases, or Respiratory Burst Oxidase Homologs (RBOHs) in plants, are enzymes that generate superoxide (O2 •-). Superoxide produces other reactive oxygen species (ROS); these ROS regulate different stages of mutualistic interactions. For example, changes in ROS levels are thought to induce ROS scavenging, cell wall remodeling, and changes in phytohormone homeostasis during symbiotic interactions. In common bean (Phaseolus vulgaris), PvRbohB plays a key role in the early stages of nodulation. RESULTS: In this study, to explore the role of PvRbohB in root nodule symbiosis, we analyzed transcriptomic data from the roots of common bean under control conditions (transgenic roots without construction) and roots with downregulated expression of PvRbohB (by RNA interference) non-inoculated and inoculated with R. tropici. Our results suggest that ROS produced by PvRBOHB play a central role in infection thread formation and nodule organogenesis through crosstalk with flavonoids, carbonmetabolism, cell cycle regulation, and the plant hormones auxin and cytokinin during the early stages of this process. CONCLUSIONS: Our findings provide important insight into the multiple roles of ROS in regulating rhizobia-legume symbiosis.
Entities:
Keywords:
Common bean; Nodulation; PvRbohB; Symbiosis; Transcriptome
Authors: Christopher D Todd; Peter A Tipton; Dale G Blevins; Pedro Piedras; Manuel Pineda; Joe C Polacco Journal: J Exp Bot Date: 2005-11-29 Impact factor: 6.992