Rhizobia are symbiotic soil bacteria able to intracellularly colonize legume nodule cells and form nitrogen-fixing symbiosomes therein. How the plant cell cytoskeleton reorganizes in response to rhizobium colonization has remained poorly understood especially because of the lack of an in vitro infection assay. Here, we report on the use of the heterologous HeLa cell model to experimentally tack...

Air pollution is the most important environmental problem of last century that threatens the health of living organisms, especially plants. SO2 is one of the main air pollutants that can cause to imbalance in growth and physiological function of plant in high concentrations. Symbiosis of Rhizobium bacteria with alfalfa can cause increasing plant growth and plant resistance to abiotic stresses. ...

A set of conserved, or common, bacterial nodulation (nod) loci is required for host plant infection by Rhizobium melioti and other Rhizobium species. Four such genes, nodDABC, have beeii indicated in R. meliloti 021'by genetic analysis and DNA sequencing. An essential step toward Iunderstanding the function of these genes is to characterize their protein products. We used in vitro and maxicell ...

Synthesis of chitin oligosaccharides by NodC is the first committed step in the biosynthesis of rhizobial lipochitin oligosaccharides (LCOs). The distribution of oligosaccharide chain lengths in LCOs differs between various Rhizobium species. We expressed the cloned nodC genes of Rhizobium meliloti, R. leguminosarum bv. viciae, and R. loti in Escherichia coli. The in vivo activities of the vari...

The development of nitrogen-fixing nodules of the Rhizobium-legume symbiosis, especially the early stages of root hair deformation and curling, infection thread formation, and nodule initiation, has been well studied from a genetic standpoint. In contrast, the factors important for the colonization of surfaces by rhizobia, including roots–an important prerequisite for nodule formation–have not ...

Rhizobium meliloti nod genes are required for the infection of alfalfa. Induction of the nodC gene depends on a chemical signal from alfalfa and on nodD gene expression. By using a nodC-lacZ fusion, we have shown that the induction of the R. meliloti nodC gene and the expression of nodD occur at almost normal levels in other Rhizobium backgrounds and in Agrobacterium tumefaciens, but not in Esc...

Cobalt is known to be essential for symbiotic nitrogen fixation by legumes (l-5), but a requirement of the element for growth of leguminous plants supplied with adequate fixed nitrogen has not been shown. Ahmed and Evans (3) provided evidence that cobalt was required for the bacteria within the nodules of inoculated legumes but was not required for the leguminous plants per se. Lowe, Evans, and...

air pollution is the most important environmental problem of last century that threatens the health of living organisms, especially plants. so2 is one of the main air pollutants that can cause to imbalance in growth and physiological function of plant in high concentrations. symbiosis of rhizobium bacteria with alfalfa can cause increasing plant growth and plant resistance to abiotic stresses. ...