2. Why is nitrogen required in plant nutrition? In what form(s) are plants able to use nitrogen? In what form does most of the nitrogen in the environment exist? How do legumes differ from other plants? Describe the process by which Rhizobium bacteria become symbiotic, nitrogen fixers within legumes. Plants require nitrogen in order to make both proteins and nucleic acids. Plants can use nitrogen of the forms NH4+ and NO3-. Most naturally occurring nitrogen exists in the form N2. Legumes differ from other plants because they are able to use the nitrogen from the air (after rhizobium processing). Flavenoids are secreted by the plant. This attracts rhizobia to the roots. The microbes release NOD factors. They then enter the root hair and a nodule forms. The microbes are fed oxygen by leghemoglobin, carbon, and energy and the plants get nitrogen. 5.
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This note was uploaded on 03/31/2008 for the course BIO 152 taught by Professor Doyle during the Spring '08 term at University of Wisconsin.