Root nodulation process and its soil ameliorating benefits: A review

Abstract

Legume plants have an extraordinary ability to combine with microorganisms which range from non-specific to very specific interaction. Legume rhizobial symbiosis results in large growth and metabolic changes for both microorganisms and hosts, while providing plants with fixed nitrogen. In a complex signal exchange rhizobia leads to selective colonization of plant cells within nodules, development of new organ known as nodule on the roots of host plants. Although the nodulation mechanism is highly specific, it contains same subset of phytohormones of plants, i.e. auxin, cytokinin, and ethylene, which are essential for root development. In addition, the formation of nodule triggered by rhizobia affect the development of host root system and indicating that microorganisms may change the developmental pathways of host. A prime example of nodulation by rhizobia is how microorganisms and plants have coevolved and illustrate how microbial colonization may affect plant developmental pathways.