Biomaterial Database

Rhizobium meliloti exopolysaccharides: synthesis and symbiotic function. 1996

J E González, and G M York, and G C Walker

Department of Biology, Massachusetts Institute of Technology, Cambridge 02139, USA.

Bacterial exopolysaccharide (EPS) is required for establishment of the nitrogen-fixing symbiosis between Rhizobium meliloti and its host plant, Medicago sativa (alfalfa), but the precise role of EPS in this interaction is not well defined. Bacterial mutants which fail to produce EPS induce nodules on the roots of the host plant, but fail to invade these root nodules. Research conducted in our lab and others suggests that EPS plays a specific role in the R. meliloti-M. sativa symbiosis. A common theme emerging from these studies is that small quantities of low-molecular-weight (LMW) EPS are sufficient to mediate successful invasion by R. meliloti mutants which fail to produce EPS, implying that LMW EPS may act as a signaling molecule during this process.

UI	MeSH Term	Description	Entries
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D010941	Plant Tumors	A localized proliferation of plant tissue forming a swelling or outgrowth, commonly with a characteristic shape and unlike any organ of the normal plant. Plant tumors or galls usually form in response to the action of a pathogen or a pest. (Holliday, P., A Dictionary of Plant Pathology, 1989, p330)	Crown Gall,Galls, Plant,Plant Galls,Crown Galls,Gall, Crown,Gall, Plant,Galls, Crown,Plant Gall,Plant Tumor,Tumor, Plant,Tumors, Plant
D011135	Polysaccharides, Bacterial	Polysaccharides found in bacteria and in capsules thereof.	Bacterial Polysaccharides
D002240	Carbohydrate Sequence	The sequence of carbohydrates within POLYSACCHARIDES; GLYCOPROTEINS; and GLYCOLIPIDS.	Carbohydrate Sequences,Sequence, Carbohydrate,Sequences, Carbohydrate
D002450	Cell Communication	Any of several ways in which living cells of an organism communicate with one another, whether by direct contact between cells or by means of chemical signals carried by neurotransmitter substances, hormones, and cyclic AMP.	Cell Interaction,Cell-to-Cell Interaction,Cell Communications,Cell Interactions,Cell to Cell Interaction,Cell-to-Cell Interactions,Communication, Cell,Communications, Cell,Interaction, Cell,Interaction, Cell-to-Cell,Interactions, Cell,Interactions, Cell-to-Cell
D000455	Medicago sativa	A plant species of the family FABACEAE widely cultivated for ANIMAL FEED.	Alfalfa,Lucerne
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
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
D018517	Plant Roots	The usually underground portions of a plant that serve as support, store food, and through which water and mineral nutrients enter the plant. (From American Heritage Dictionary, 1982; Concise Dictionary of Biology, 1990)	Plant Bulbs,Plant Root,Bulb, Plant,Bulbs, Plant,Plant Bulb,Root, Plant,Roots, Plant