HH103 RirA Is Required for Oxidative Stress Resistance and Efficient Symbiosis with Soybean.

Juan Carlos Crespo-Rivas, Pilar Navarro-Gómez, Cynthia Alias-Villegas, Jie Shi, Tao Zhen, Yanbo Niu, Virginia Cuéllar, Javier Moreno, Teresa Cubo, José María Vinardell, José Enrique Ruiz-Sainz, Sebastián Acosta-Jurado, María José Soto

Journal: International journal of molecular sciences 2019;20(3):787

PMID: 30759803

Free Full Text on MDPI View on PubMed

Abstract

Members of contain a homologue of the iron-responsive regulatory protein RirA. In different bacteria, RirA acts as a repressor of iron uptake systems under iron-replete conditions and contributes to ameliorate cell damage during oxidative stress. In and , mutations in do not impair symbiotic nitrogen fixation. In this study, a mutant of broad host range HH103 has been constructed (SVQ780) and its free-living and symbiotic phenotypes evaluated. No production of siderophores could be detected in either the wild-type or SVQ780. The mutant exhibited a growth advantage under iron-deficient conditions and hypersensitivity to hydrogen peroxide in iron-rich medium. Transcription of in HH103 is subject to autoregulation and inactivation of the gene upregulates , a gene putatively involved in iron transport. The mutant was able to nodulate soybean plants, but symbiotic nitrogen fixation was impaired. Nodules induced by the mutant were poorly infected compared to those induced by the wild-type. Genetic complementation reversed the mutant's hypersensitivity to H₂O₂, expression of , and symbiotic deficiency in soybean plants. This is the first report that demonstrates a role for RirA in the -legume symbiosis.

Address: Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avda. Reina Mercedes 6, 41012 Sevilla, Spain. [email protected].; Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avda. Reina Mercedes 6, 41012 Sevilla, Spain. [email protected].; Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avda. Reina Mercedes 6, 41012 Sevilla, Spain. [email protected].; Daqing Branch of Heilongjiang Academy of Sciences, Daqing 163000, China. [email protected].; Institute of Microbiology, Heilongjiang Academy of Sciences, Harbin 150001, China. [email protected].; Institute of Microbiology, Heilongjiang Academy of Sciences, Harbin 150001, China. [email protected].; Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, CSIC, c/ Profesor Albareda 1, 18008 Granada, Spain. [email protected].; Departamento de Biología Celular, Facultad de Biología, Universidad de Sevilla, Avda. Reina Mercedes 6, 41012 Sevilla, Spain. [email protected].; Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avda. Reina Mercedes 6, 41012 Sevilla, Spain. [email protected].; Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avda. Reina Mercedes 6, 41012 Sevilla, Spain. [email protected].; Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avda. Reina Mercedes 6, 41012 Sevilla, Spain. [email protected].; Departamento de Microbiología, Facultad de Biología, Universidad de Sevilla, Avda. Reina Mercedes 6, 41012 Sevilla, Spain. [email protected].; Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, CSIC, c/ Profesor Albareda 1, 18008 Granada, Spain. [email protected].

DOI: 10.3390/ijms20030787

Link outs

Free resources

Full Text Sources:

MeSH Terms: Bacterial Proteins, Fabaceae, Genes, Bacterial, Hydrogen Peroxide, Iron, Nitrogen Fixation, Oxidative Stress, Rhizobium leguminosarum, Siderophores, Sinorhizobium fredii, Sinorhizobium meliloti, Glycine max, Symbiosis, Transcription, Genetic