**2. Importance of P for plants**

P is engaged in biological processes that are shared by all living species [1, 2, 9]. P, in particular, is the second most limiting macronutrient for plant growth, accounting for 0.2% of plant dry weight [10, 11] and serving as a critical element in animal bodies [12–14]. As a result, P has become a fundamental and necessary component for human well-being [15].

Functions of P in all living organisms included energy metabolism and transmission [1, 9], cell division [2], protein and nucleic acids (DNA and RNA) synthesis [9, 16, 17], being a key component of enzymes, coenzymes, and phospholipids [18] and cell division [2]. In addition, P is essential for plants for photosynthesis [2], nitrogen fixation [14], improving crop quality [14, 16], development of disease resistance [18], root development [3], development of the stems and stalks [15], flower and seed formation [10], conversion of sugar to starch [10], laying down the primordia of propagative parts during the early stages of plant development [16], and proper stress reduction and maturation of plant [10]. A lack of phosphorus can lead to stunted growth, delayed maturity, and lower yield. Therefore, it is essential to ensure that plants receive adequate phosphorus to maintain their health and productivity.

The world population is expected to exceed 9000 million in 2050 [19] and food production requires to be increased globally by 50% as compared to the demand in 2012 [20]. Usability of phosphate has been severely limited due to its low bioavailability. Furthermore, the wastage of phosphate that is unable to be utilised by plants and animals causes additional issues such as eutrophication [10, 21]. The low bioavailability of phosphate is driving its increasing usage, with peak extraction occurring in 2030 [22]. Therefore, the sustainable utilisation of phosphate is needed to increase its bioavailability to avoid the wastage of phosphate [4]. Using microorganisms to increase the bioavailability of phosphate is the emerging eco-friendly technique for sustainable utilisation of phosphate [10, 23].
