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The nif genes are genes encoding enzymes involved in the fixation of atmospheric nitrogen into a form of nitrogen available to living organisms. The primary enzyme encoded by the nif genes is the nitrogenase complex which is in charge of converting atmospheric nitrogen (N 2) to other nitrogen forms such as ammonia which the organism can use for various purposes.
Plants that contribute to nitrogen fixation include those of the legume family—Fabaceae— with taxa such as kudzu, clover, soybean, alfalfa, lupin, peanut and rooibos. [45] They contain symbiotic rhizobia bacteria within nodules in their root systems, producing nitrogen compounds that help the plant to grow and compete with other plants. [58]
Zone III—the nitrogen fixation zone. Each cell in this zone contains a large, central vacuole and the cytoplasm is filled with fully differentiated bacteroids which are actively fixing nitrogen. The plant provides these cells with leghemoglobin, resulting in a distinct pink color. Zone IV—the senescent zone. Here plant cells and their ...
Actinorhizal plants are distributed within three clades, [1] and are characterized by nitrogen fixation. [2] They are distributed globally, and are pioneer species in nitrogen-poor environments. Their symbiotic relationships with Frankia evolved independently over time, [ 3 ] and the symbiosis occurs in the root nodule infection site.
Nitrogen assimilation is the formation of organic nitrogen compounds like amino acids from inorganic nitrogen compounds present in the environment. Organisms like plants, fungi and certain bacteria that can fix nitrogen gas (N 2) depend on the ability to assimilate nitrate or ammonia for their needs. Other organisms, like animals, depend ...
Rhizobium is a genus of Gram-negative soil bacteria that fix nitrogen. Rhizobium species form an endosymbiotic nitrogen-fixing association with roots of (primarily) legumes and other flowering plants. The bacteria colonize plant cells to form root nodules, where they convert atmospheric nitrogen into ammonia using the enzyme nitrogenase.
The nitrogen-fixing clade consists of four orders of flowering plants: Cucurbitales, Fabales, Fagales and Rosales. [a] This subgroup of the rosids encompasses 28 families of trees, shrubs, vines and herbaceous perennials and annuals. The roots of many of the species host bacteria that fix nitrogen into compounds the plants can use. [4] [5]
Abiological nitrogen fixation describes chemical processes that fix (react with) N 2, usually with the goal of generating ammonia. The dominant technology for abiological nitrogen fixation is the Haber process, which uses iron-based heterogeneous catalysts and H 2 to convert N 2 to NH 3. This article focuses on homogeneous (soluble) catalysts ...