title: Transcript profiling of common bean nodules subjected to oxidative stress.
abstract: Several environmental stresses generate high amounts of reactive oxygen species (ROS) in plant cells, resulting in oxidative stress. Symbiotic nitrogen fixation (SNF) in the legume-rhizobia symbiosis is sensitive to damage from oxidative stress. Active nodules of the common bean (Phaseolus vulgaris) exposed to the herbicide paraquat (1,1'-dimethyl-4,4'-bipyridinium dichloride hydrate), which stimulates ROS accumulation, exhibited reduced nitrogenase activity and ureide content. We analyzed the global gene response of nodules subjected to oxidative stress using the Bean Custom Array 90K, which includes probes from 30,000 expressed sequence tags (ESTs). A total of 4280 ESTs were differentially expressed in stressed bean nodules; of these, 2218 were repressed. Based on Gene Ontology analysis, these genes were grouped into 42 different biological process categories. Analysis with the PathExpress bioinformatic tool, adapted for bean, identified five significantly repressed metabolic pathways related to carbon/nitrogen metabolism, which is crucial for nodule function. Quantitative reverse transcription (qRT)-PCR analysis of transcription factor (TF) gene expression showed that 67 TF genes were differentially expressed in nodules exposed to oxidative stress. Putative cis-elements recognized by highly responsive TF were detected in promoter regions of oxidative stress regulated genes. The expression of oxidative stress responsive genes and of genes important for SNF in bacteroids analyzed in stressed nodules revealed that these conditions elicited a transcriptional response.
authors: Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Av. Universidad 1001, Cuernavaca, Mor. 62209, Mexico.
authors: Mario
authors: M
authors: Ramírez
authors: Gabriel
authors: G
authors: Guillén
authors: Sara I
authors: SI
authors: Fuentes
authors: Luis P
authors: LP
authors: Iñiguez
authors: Rosaura
authors: R
authors: Aparicio-Fabre
authors: David
authors: D
authors: Zamorano-Sánchez
authors: Sergio
authors: S
authors: Encarnación-Guevara
authors: Dario
authors: D
authors: Panzeri
authors: Bianca
authors: B
authors: Castiglioni
authors: Paola
authors: P
authors: Cremonesi
authors: Francesco
authors: F
authors: Strozzi
authors: Alessandra
authors: A
authors: Stella
authors: Lourdes
authors: L
authors: Girard
authors: Francesca
authors: F
authors: Sparvoli
authors: Georgina
authors: G
authors: Hernández
mesh_terms: D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D020411:Oligonucleotide Array Sequence Analysis; D018384:Oxidative Stress / Q000235:genetics; D010269:Paraquat; D027805:Phaseolus / Q000235:genetics* / Q000378:metabolism; D010641:Phenotype; D010940:Plant Proteins / Q000235:genetics / Q000502:physiology; D011401:Promoter Regions, Genetic; D020133:Reverse Transcriptase Polymerase Chain Reaction; D042162:Rhizobium tropici / Q000235:genetics / Q000378:metabolism; D053204:Root Nodules, Plant / Q000235:genetics* / Q000378:metabolism; D013559:Symbiosis; D014157:Transcription Factors / Q000235:genetics*
chemical_list: D010940:Plant Proteins; D014157:Transcription Factors; D010269:Paraquat