RHIZOBIA, NOD FACTORS AND NODULATION– A REVIEW
Citation :- RHIZOBIA, NOD FACTORS AND NODULATION– A REVIEW.Agricultural Reviews.2008.(29):200 - 206
Soil bacteria, referred as rhizobia have unique ability to form nodules on the roots and stems of leguminous plants. This endosymbiotic relationship between rhizobia and their corresponding hosts lead to morphogenesis of specialized structures, nodules, where atmospheric nitrogen is reduced to ammonia and assimilated by the host plant. The process of nodulation is regulated by the exchange of molecular signals between the two partners. The nodulation process is host specific and specific rhizobia can form nodules on specific hosts. Rhizobia carry host specific nodulation genes. These genes are induced by regulatory genes activated by flavonoids present in the root exudates. The product of nodulation genes are involved in the synthesis of Nod factors which are involved in the morphogenesis of nodules. The present review summarizes the structure and function of Nod factors, the gene and gene products involved in their synthesis and their host specificity.
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