The Fabaceae or Leguminosae, commonly known as the legume, pea, or bean family, are a large and agriculturally important family of flowering plants. It includes trees, shrubs, and perennial or annual herbaceous plants, which are easily recognized by their fruit (legume) and their compound, stipulate leaves. The family is widely distributed, and is the third-largest land plant family in number of species, behind only the Orchidaceae and Asteraceae, with about 765 genera and nearly 20,000 known species.
The honey locust, also known as the thorny locust or thorny honeylocust, is a deciduous tree in the family Fabaceae, native to central North America where it is mostly found in the moist soil of river valleys. Honey locust trees are highly adaptable to different environments, and the species has been introduced worldwide. Outside its natural range it can be an aggressive, damaging invasive species.
Rhizobia are diazotrophic bacteria that fix nitrogen after becoming established inside the root nodules of legumes (Fabaceae). To express genes for nitrogen fixation, rhizobia require a plant host; they cannot independently fix nitrogen. In general, they are gram negative, motile, non-sporulating rods.
Ensifer meliloti are an aerobic, Gram-negative, and diazotrophic species of bacteria. S. meliloti are motile and possess a cluster of peritrichous flagella. S. meliloti fix atmospheric nitrogen into ammonia for their legume hosts, such as alfalfa. S. meliloti forms a symbiotic relationship with legumes from the genera Medicago, Melilotus and Trigonella, including the model legume Medicago truncatula. This symbiosis promotes the development of a plant organ, termed a root nodule. Because soil often contains a limited amount of nitrogen for plant use, the symbiotic relationship between S. meliloti and their legume hosts has agricultural applications. These techniques reduce the need for inorganic nitrogenous fertilizers.
Root nodules are found on the roots of plants, primarily legumes, that form a symbiosis with nitrogen-fixing bacteria. Under nitrogen-limiting conditions, capable plants form a symbiotic relationship with a host-specific strain of bacteria known as rhizobia. This process has evolved multiple times within the legumes, as well as in other species found within the Rosid clade. Legume crops include beans, peas, and soybeans.
Symbiotic bacteria are bacteria living in symbiosis with another organism or each other. For example, rhizobia living in root nodules of legumes provide nitrogen fixing activity for these plants.
Bradyrhizobium is a genus of Gram-negative soil bacteria, many of which fix nitrogen. Nitrogen fixation is an important part of the nitrogen cycle. Plants cannot use atmospheric nitrogen (N2); they must use nitrogen compounds such as nitrates.
Actinorhizal plants are a group of angiosperms characterized by their ability to form a symbiosis with the nitrogen fixing actinomycetota Frankia. This association leads to the formation of nitrogen-fixing root nodules.
Trigonella suavissima is a herbaceous plant that is endemic to Australia. It is a member of the genus Trigonella and the family Fabaceae. Common names include Cooper clover, Menindee clover, calomba, Darling trigonella, sweet fenugreek, channel clover, sweet-scented clover and Australian shamrock.
Rhizobium gallicum is a Gram-negative root-nodule bacterium. It forms nitrogen-fixing root nodules on legumes, being first isolated from those of Phaseolus vulgaris.
Bradyrhizobium arachidis is a species of legume-root nodulating, microsymbiotic nitrogen-fixing bacterium. It was first isolated from Arachis hypogaea root nodules in China. Its type strain is CCBAU 051107T.
Bradyrhizobium liaoningense is a species of legume-root nodulating, microsymbiotic nitrogen-fixing bacterium. It was first isolated from Glycine soja and Glycine max root nodules in China. Its type strain is strain 2281.
Bradyrhizobium canariense is a species of legume-root nodulating, endosymbiont nitrogen-fixing bacterium. It is acid-tolerant and nodulates endemic genistoid legumes from the Canary Islands. The type strain is BTA-1T.
Bradyrhizobium yuanmingense is a species of legume-root nodulating, endosymbiont nitrogen-fixing bacterium, associated with Lespedeza and Vigna species. Its type strain is CCBAU 10071(T).
Mesorhizobium mediterraneum is a bacterium from the genus Mesorhizobium, which was isolated from root nodule of the Chickpea in Spain. The species Rhizobium mediterraneum was subsequently transferred to Mesorhizobium mediterraneum. This species, along with many other closely related taxa, have been found to promote production of chickpea and other crops worldwide by forming symbiotic relationships.
Devosia neptuniae is a nitrogen-fixing bacteria that nodulates Neptunia natans. It is Gram-negative, strictly aerobic short rod-shaped and motile by a subpolar flagellum. The type strain of D. neptuniae is LMG 21357T.
Ensifer americanus is a bacterium first isolated from root nodules of Acacia species native of Mexico. Its type strain is CFNEI 156.
A symbiosome is a specialised compartment in a host cell that houses an endosymbiont in a symbiotic relationship.
Ensifer numidicus is a nitrogen fixing symbiont of Fabaceae. gram-negative, aerobic, non-spore forming, rod-shaped bacterium of the family Rhizobiaceae. First described in 2010; more biovars have since been isolated and described with ORS 1407 considered the representative organism. Most examples have been found in arid and infra-arid regions of Tunisia.
Lotus creticus is a species of perennial herb of the family Fabaceae found in tropical Africa. It is symbiosis competent and engages in nitrogen-fixing symbiotic interactions with species of the Ensifer genus It comprises three varieties found in the Mediterranean although there is some controversy as to whether each subgroup could be considered the same species but are classically described as being subgroups. Varieties consist of the most commonly cited silky-hairy var. creticus which is widely distributed in its western part of the coast, the non-silky var. glabrescens which has a western Mediterranean distribution; and the eastern Mediterranean var. collinus which is also not silky and can be described by long petioles and peduncles.
