Biomaterial Database

Role of quorum sensing in Sinorhizobium meliloti-Alfalfa symbiosis. 2009

Nataliya Gurich, and Juan E González

Department of Molecular and Cell Biology, University of Texas at Dallas, Richardson, Texas 75080-0688, USA.

The ExpR/Sin quorum-sensing system of the gram-negative soil bacterium Sinorhizobium meliloti plays an important role in the establishment of symbiosis with its host plant Medicago sativa. A mutant unable to produce autoinducer signal molecules (sinI) is deficient in its ability to invade the host, but paradoxically, a strain lacking the quorum-sensing transcriptional regulator ExpR is as efficient as the wild type. We compared the whole-genome expression profile of the wild-type strain with strains missing one of the quorum-sensing regulatory components to identify genes controlled by the ExpR/Sin system throughout the different phases of the bacterial growth cycle, as well as in planta. Our analyses revealed that ExpR is a highly versatile regulator with a unique ability to show different regulatory capabilities in the presence or absence of an autoinducer. In addition, this study provided us with insight into the plant invasion defect displayed by the autoinducer mutant. We also discovered that the ExpR/Sin quorum-sensing system is repressed after plant invasion. Therefore, quorum sensing plays a crucial role in the regulation of many cell functions that ensures the successful invasion of the host and is inactivated once symbiosis is established.

UI	MeSH Term	Description	Entries
D008954	Models, Biological	Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.	Biological Model,Biological Models,Model, Biological,Models, Biologic,Biologic Model,Biologic Models,Model, Biologic
D005816	Genetic Complementation Test	A test used to determine whether or not complementation (compensation in the form of dominance) will occur in a cell with a given mutant phenotype when another mutant genome, encoding the same mutant phenotype, is introduced into that cell.	Allelism Test,Cis Test,Cis-Trans Test,Complementation Test,Trans Test,Allelism Tests,Cis Tests,Cis Trans Test,Cis-Trans Tests,Complementation Test, Genetic,Complementation Tests,Complementation Tests, Genetic,Genetic Complementation Tests,Trans Tests
D000455	Medicago sativa	A plant species of the family FABACEAE widely cultivated for ANIMAL FEED.	Alfalfa,Lucerne
D001426	Bacterial Proteins	Proteins found in any species of bacterium.	Bacterial Gene Products,Bacterial Gene Proteins,Gene Products, Bacterial,Bacterial Gene Product,Bacterial Gene Protein,Bacterial Protein,Gene Product, Bacterial,Gene Protein, Bacterial,Gene Proteins, Bacterial,Protein, Bacterial,Proteins, Bacterial
D013559	Symbiosis	The relationship between two different species of organisms that are interdependent; each gains benefits from the other or a relationship between different species where both of the organisms in question benefit from the presence of the other.	Endosymbiosis,Commensalism,Mutualism
D015964	Gene Expression Regulation, Bacterial	Any of the processes by which cytoplasmic or intercellular factors influence the differential control of gene action in bacteria.	Bacterial Gene Expression Regulation,Regulation of Gene Expression, Bacterial,Regulation, Gene Expression, Bacterial
D016962	Sinorhizobium meliloti	A species of gram-negative, aerobic bacteria that causes formation of root nodules on some, but not all, types of sweet clover, MEDICAGO SATIVA, and fenugreek.	Ensifer meliloti,Rhizobium meliloti
D053038	Quorum Sensing	A phenomenon where microorganisms communicate and coordinate their behavior by the accumulation of signaling molecules. A reaction occurs when a substance accumulates to a sufficient concentration. This is most commonly seen in bacteria.	Quorum Quenching,Quenching, Quorum,Quenchings, Quorum,Quorum Quenchings,Sensing, Quorum
D020133	Reverse Transcriptase Polymerase Chain Reaction	A variation of the PCR technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard PCR protocols.	Polymerase Chain Reaction, Reverse Transcriptase,Reverse Transcriptase PCR,PCR, Reverse Transcriptase,Transcriptase PCR, Reverse
D020411	Oligonucleotide Array Sequence Analysis	Hybridization of a nucleic acid sample to a very large set of OLIGONUCLEOTIDE PROBES, which have been attached individually in columns and rows to a solid support, to determine a BASE SEQUENCE, or to detect variations in a gene sequence, GENE EXPRESSION, or for GENE MAPPING.	DNA Microarrays,Gene Expression Microarray Analysis,Oligonucleotide Arrays,cDNA Microarrays,DNA Arrays,DNA Chips,DNA Microchips,Gene Chips,Oligodeoxyribonucleotide Array Sequence Analysis,Oligonucleotide Microarrays,Sequence Analysis, Oligonucleotide Array,cDNA Arrays,Array, DNA,Array, Oligonucleotide,Array, cDNA,Arrays, DNA,Arrays, Oligonucleotide,Arrays, cDNA,Chip, DNA,Chip, Gene,Chips, DNA,Chips, Gene,DNA Array,DNA Chip,DNA Microarray,DNA Microchip,Gene Chip,Microarray, DNA,Microarray, Oligonucleotide,Microarray, cDNA,Microarrays, DNA,Microarrays, Oligonucleotide,Microarrays, cDNA,Microchip, DNA,Microchips, DNA,Oligonucleotide Array,Oligonucleotide Microarray,cDNA Array,cDNA Microarray