Biotechnological Approaches for Improving Phosphate Uptake and Assimilation in Plants

Phosphorus is one of the essential macronutrients for plant growth. However, its low solubility and high fixation in soil restrict the root P uptake. Therefore, plants have evolved with several adaptations to combat soil P deficiency to allow their development. This includes modification in root architecture to increase surface area for P absorption. Similarly, plants undergo changes in the activity of P transporters and their regulatory elements to enhance the P uptake and distribution. The involvement of secreted purple acid phosphatases (PAPs) and organic acids helps to hydrolyse organic P available in the soil. In addition, plants increase the P-use efficiency (PUE) by utilising internal P and undergoing membrane lipid remodelling, releasing cytosolic Pi, and utilising vacuolar P. To date, various biotechnological approaches such as overexpression, knockout, and gene editing have been adopted to increase P absorption and availability for plants. Here, we review different biotechnological studies that have been undertaken for manipulating different P uptake and utilisation-associated genes. We discuss how targeting genes related to topsoil foraging, P transportation, metabolic pathways, and internal recycling could improve P acquisition and utilisation for plants. We also discuss several novel strategies that could serve as useful tools for crop improvement.