title: PvRbohB negatively regulates Rhizophagus irregularis colonization in Phaseolus vulgaris.
abstract: Plant NADPH oxidases (RBOHs) regulate the early stages of rhizobial infection in Phaseolus vulgaris and affect nodule function in Medicago truncatula. In contrast, the role of RBOHs in the plant-arbuscular mycorrhizal (AM) symbiosis and in the regulation of reactive oxygen species (ROS) production during the establishment of the AM interaction is largely unknown. In this study, we assessed the role of P. vulgaris Rboh (PvRbohB) during the symbiosis with the AM fungus, Rhizophagus irregularis. Our results indicate that the PvRbohB transcript is significantly up-regulated in the mycorrhized roots of P. vulgaris. Further, the PvRbohB promoter was found to be active during the invasion of R. irregularis. Down-regulation of PvRbohB transcription by RNAi (RNA interference) silencing resulted in diminished ROS levels in the transgenic mycorrhized roots and induced early hyphal root colonization. Interestingly, the size of appressoria increased in PvRbohB-RNAi roots (760 ± 70.1 µm) relative to controls (251 ± 73.2 µm). Finally, the overall level of mycorrhizal colonization significantly increased in PvRbohB-RNAi roots [48.1 ± 3.3% root length colonization (RLC)] compared with controls (29.4 ± 1.9% RLC). We propose that PvRbohB negatively regulates AM colonization in P. vulgaris.
authors.affiliation: Departamento de Biología Molecular de Plantas, Instituto de Biotecnología, Universidad Nacional Autónoma de México, UNAM, Apartado Postal 510-3, Cuernavaca, Morelos 62271, México.
authors.forename: Manoj-Kumar
authors.initials: MK
authors.lastname: Arthikala
authors.forename: Jesús
authors.initials: J
authors.lastname: Montiel
authors.forename: Noreide
authors.initials: N
authors.lastname: Nava
authors.forename: Olivia
authors.initials: O
authors.lastname: Santana
authors.forename: Rosana
authors.initials: R
authors.lastname: Sánchez-López
authors.forename: Luis
authors.initials: L
authors.lastname: Cárdenas
authors.forename: Carmen
authors.initials: C
authors.lastname: Quinto
mesh_terms: D015536:Down-Regulation; D018506:Gene Expression Regulation, Plant; D017930:Genes, Reporter; D055137:Glomeromycota / Q000502:physiology*; D038821:Mycorrhizae / Q000166:cytology / Q000235:genetics* / Q000502:physiology; D019255:NADPH Oxidases / Q000235:genetics* / Q000378:metabolism; D027805:Phaseolus / Q000166:cytology / Q000235:genetics* / Q000382:microbiology / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000166:cytology / Q000235:genetics / Q000382:microbiology / Q000502:physiology; D034622:RNA Interference; D017382:Reactive Oxygen Species / Q000032:analysis / Q000378:metabolism*; D013559:Symbiosis
chemical_list: D010940:Plant Proteins; D017382:Reactive Oxygen Species; D019255:NADPH Oxidases
keywords: Arbuscular mycorrhiza; Common bean; ROS; Rbohs