Medicago is a genus of flowering plants, commonly known as medick or burclover, in the legume family (Fabaceae). It contains at least 87 species and is distributed mainly around the Mediterranean basin. The best-known member of the genus is alfalfa, an important forage crop, and the genus name is based on the Latin name for that plant, medica, from Greek: μηδική (πόα) Median (grass). Most members of the genus are low, creeping herbs, resembling clover, but with burs. However, alfalfa grows to a height of 1 meter, and tree medick is a shrub. Members of the genus are known to produce bioactive compounds such as medicarpin and medicagenic acid. Chromosome numbers in Medicago range from 2n = 14 to 48.
Lectins are carbohydrate-binding proteins that are highly specific for sugar groups that are part of other molecules, so cause agglutination of particular cells or precipitation of glycoconjugates and polysaccharides. Lectins have a role in recognition at the cellular and molecular level and play numerous roles in biological recognition phenomena involving cells, carbohydrates, and proteins. Lectins also mediate attachment and binding of bacteria, viruses, and fungi to their intended targets.
Medicago truncatula, the barrelclover, strong-spined medick, barrel medic, or barrel medick, is a small annual legume native to the Mediterranean region that is used in genomic research. It is a low-growing, clover-like plant 10–60 centimetres (3.9–23.6 in) tall with trifoliate leaves. Each leaflet is rounded, 1–2 centimetres (0.39–0.79 in) long, often with a dark spot in the center. The flowers are yellow, produced singly or in a small inflorescence of two to five together; the fruit is a small, spiny pod.
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 symbionts, 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.
Nod factors, are signaling molecules produced by soil bacteria known as rhizobia in response to flavonoid exudation from plants under nitrogen limited conditions. Nod factors initiate the establishment of a symbiotic relationship between legumes and rhizobia by inducing nodulation. Nod factors produce the differentiation of plant tissue in root hairs into nodules where the bacteria reside and are able to fix nitrogen from the atmosphere for the plant in exchange for photosynthates and the appropriate environment for nitrogen fixation. One of the most important features provided by the plant in this symbiosis is the production of leghemoglobin, which maintains the oxygen concentration low and prevents the inhibition of nitrogenase activity.
Sharon Rugel Long is an American plant biologist. She is the Steere-Pfizer Professor of Biological Science in the Department of Biology at Stanford University, and the Principal Investigator of the Long Laboratory at Stanford.
Ensifer is a genus of nitrogen-fixing bacteria (rhizobia), three of which have been sequenced.
Medicago polymorpha is a plant species of the genus Medicago. It is native to the Mediterranean basin but is found throughout the world. It forms a symbiotic relationship with the bacterium Sinorhizobium medicae, which is capable of nitrogen fixation. Common names include California burclover, toothed bur clover, toothed medick and burr medic.
Medicago constricta is an annual, non-climbing species of the genus Medicago. It is found in the Mediterranean basin from Greece to Israel. M. constricta is found primarily in sandy clay or dry soils. It forms a symbiotic relationship with the bacterium Sinorhizobium meliloti, which is capable of nitrogen fixation.
Medicago laciniata is a plant species of the genus Medicago. It is found primarily in the southern Mediterranean basin. It forms a symbiotic relationship with the bacterium Sinorhizobium meliloti, which is capable of nitrogen fixation. Common names include cutleaf medick and tattered medick. Grows in Sinai, Egypt.
Medicago littoralis is a plant species of the genus Medicago. It is found primarily in the Mediterranean basin. It forms a symbiotic relationship with the bacterium Sinorhizobium meliloti, which is capable of nitrogen fixation. Common names include shore medick, water medick, coastal medick, and strand medick.
Medicago orbicularis is a plant species found throughout the Mediterranean basin and along the European Black Sea coast. It forms a symbiotic relationship with the bacterium Sinorhizobium medicae, which is capable of nitrogen fixation. Common names include blackdisk medick, button clover, button medick, and round-fruited medick.
Medicago radiata, the ray-podded medick, is a plant species of the genus Medicago. It is found throughout the eastern Mediterranean and in Asia. It forms a symbiotic relationship with the bacterium Sinorhizobium meliloti, which is capable of nitrogen fixation.
Medicago scutellata is a plant species of the genus Medicago. It is found throughout the Mediterranean basin. It forms a symbiotic relationship with the bacterium Sinorhizobium meliloti, which is capable of nitrogen fixation. Common names include snail medick and shield medick.
Peanut agglutinin (PNA) is plant lectin protein derived from the fruits of Arachis hypogaea. Peanut agglutinin may also be referred to as Arachis hypogaea lectin. Lectins recognise and bind particular sugar sequences in carbohydrates; peanut agglutinin binds the carbohydrate sequence Gal-β(1-3)-GalNAc. The name "peanut agglutinin" originates from its ability to stick together (agglutinate) cells, such as neuraminidase-treated erythrocytes, which have glycoproteins or glycolipids on their surface which include the Gal-β(1-3)-GalNAc carbohydrate sequence.
enod40, also known as early nodulin 40, is a gene found in flowering plants. The gene has characteristics of both protein and Non-coding RNA genes. There is some evidence that the non-coding characteristics of this gene are more widely conserved than the protein coding sequences. In soyabeans enod40 was found to be expressed during early stages of formation of nitrogen-fixing root nodules that are associated with symbiotic soil rhizobial bacteria. The gene is also active in roots containing fungi forming phosphate-acquiring arbuscular mycorrhiza. An interaction with a novel RNA-binding protein MtRBP1 investigated in the development of Root nodule suggests ENOD40 has a function of cytoplasmic relocalization of nuclear proteins. In the study of non-legume plants, the over-expression of ENOD40 in transgenic Arabidopsis lines was observed a reduction of cell expansion.
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.
4′,7-Dihydroxyflavone is a flavone. It is found in Medicago truncatula in relation with the root nodulation symbiont Sinorhizobium meliloti or in seeds of Sophora viciifolia.
Ensifer medicae is a species of gram-negative, nitrogen-fixing, rod-shaped bacteria. They can be free-living or symbionts of leguminous plants in root nodules. E.medicae was first isolated from root nodules on plants in the genus Medicago. Some strains of E.medicae, like WSM419, are aerobic. They are chemoorganotrophic mesophiles that prefer temperatures around 28 °C. In addition to their primary genome, these organisms also have three known plasmids, sized 1,570,951 bp, 1,245,408 bp and 219,313 bp.
