During 1951 and 1952 various leguminous plants from the grounds, gardens, and greenhouses of Vassar College were collected and examined for the presence of root nodules. On the day of collection nodules were plated with medium # 79 (Fred and Waksman, 1928). Nodules from soybeans, clover, peas, beans, alfalfa, lespedeza, hairy vetch and birdsfoot trefoil contained viable rhizobia. On the same da...

Rhizobia are soil bacteria that are able to form symbiosis with plant hosts of the legume family. These associations result in the formation of organs, called nodules in which bacteria fix atmospheric nitrogen to the benefit of the plant. Most of our knowledge on the metabolism and the physiology of the bacteria during symbiosis derives from studying roots nodules of terrestrial plants. Here we...

Chickpea (Cicer arietinum) is one of the most significant legume crops and supply high-quality protein for human nutrition. such as chickpea are important agriculturally because their symbiotic ability to nitrogen fixation with specific soil bacteria. Legumes like depend on provided by activity grow, but these rhizobium bacteria affected plant-parasitic nematodes that cause less decrease number...

In the symbiosis between rhizobia and legumes, host plants can form symbiotic root nodules with multiple rhizobial strains, potentially showing different symbiotic performances in nitrogen fixation. Here, we investigated the presence of mixed nodules, containing rhizobia with different degrees of mutualisms, and evaluate their relative fitness in the Sinorhizobium meliloti-Medicago sativa model...

A method has been developed for culturing detached nitrogen-fixing root nodules of lupin (Lupinus angustifolius L.) on a simple nutrient medium. Under the best conditions devised, the acetylene reduction activity of mature detached nodules was maintained at 10 to 25 nmoles of ethylene hr(-1) mg(-1) fresh weight for 3 days. Under the same culture conditions, immature nodules increased their acet...

Nitric oxide (NO) is emerging as an important regulatory player in the Rhizobium-legume symbiosis, but its biological role in nodule functioning is still far from being understood. To unravel the signal transduction cascade and ultimately NO function, it is necessary to identify its molecular targets. This study provides evidence that glutamine synthetase (GS), a key enzyme for root nodule meta...

AP is involved in the destruction of harmful H202. In soybean (Glycine m a x [LI Merr.) root nodules, AP initiates a sequence of coupled redox reactions (ascorbate-GSH pathway) that results in peroxide scavenging (Dalton et al., 1986). The ascorbate-GSH pathway occurs in other plant tissues and has been extensively studied in chloroplasts where photoreducing conditions lead to the production of...

A region of DNA which determined the production of the insecticidal toxin of Bacillus thuringiensis subsp. israelensis was cloned into a derivative of a broad-host-range group IncQ plasmid vector of gram-negative bacteria. The plasmid which we constructed was transferred by conjugative mobilization into a Bradyrhizobium species that nodulates pigeon peas. In this species the construction was ma...

Nodulin-26 (N-26) is a major peribacteroid membrane protein in soybean root nodules. The gene encoding this protein is a member of an ancient gene family conserved from bacteria to humans. N-26 is specifically expressed in root nodules, while its homolog, soybean putative channel protein, is expressed in vegetative parts of the plant, with its highest level in the root elongation zone. Analysis...