Phosphate Starvation Responses in Plants and Microbe Mediated Phosphorus Recycling in Soil: A Review

Phosphorus (P) is an essential macronutrient, crucial for intensification of agricultural production. Although P is a vital nutrient for all life forms but in natural ecosystem it is least available owing to its high reactive nature. Plants have developed diverse adaptive strategies to improve Pi acquisition and utilization under inadequate condition. They undergo numerous modifications at morphological, physiological, and biochemical level to maintain P homeostasis under deplete conditions of P. In last decades, notable development has been made in utilizing microbes for regulating P supply in soil solution. In this review, we focused on the understanding of P uptake from soil, mobilization within plants, phosphate starvation responses and efficacy of microorganisms in facilitating external P to plants. Moreover, other metabolism in microorganism viz. phosphate accumulation is an important trait of microbes to maintain labile P in soil solution. Application of phosphate accumulating microbes is well known in enhanced biological phosphorus removal (EBPR) system and heavy metal remediation. This review also discussed the phosphate accumulation mechanism in microbes and their importance in regulating P supply in soil. Current knowledge and further exploration of mechanism involved by P accumulating microbes may offer better insight of the regulatory events controlling P homeostasis. It will be beneficial for developing more efficient sustainable technologies to augment P use efficiency in soil for better plant growth promotion and nutrient starvation alleviation.