Rhizobium-Legume Symbiosis: Molecular Determinants and Geospecificity

Symbiosis in legume plants is an ever evolving research as the factors that initiate, regulate and accomplish the complex relationship between the plant and microorganisms are very dynamic. Rhizobium is a common symbiont in legumes which throughout the process of evolution, has undergone multiple phenotypic and genotypic manifestations. Crop specificity based on the compatible combination of plant and rhizobium is, of course, the modern concept in advanced biofertilizer research. Yet, the biofertilizers are not being considered as replacement of synthetic fertilizers, but just an alternative to the chemical fertilizers. It is clearly evident from both the usage and yielding perspectives that biofertilizers are not the priority of the farming communities. A serious fundamental amendment in the research of biofertilizers is proposed in this review article in the name of Geo specificity. Exploring the natural combination of rhizobium and legume plants with respect to geography and reinoculating in the same geographical region is the central dogma of the concept. Rhizobium of one geography could be sensitive to other geographies even though the crop remains the same. Therefore a new consideration in the biofertilizer research is proposed, presented and illustrated in this review to give more insights about Bio-Geo Specificity.