Allocation of leaf phosphorus (P) among different functional fractions—including inorganic P, metabolite P, nucleic acid P, lipid P, and residual P (hereafter referred to as leaf P fractions)— varies considerably both within and among species. Yet, it remains largely unclear how leaf P fractions are associated with plant ecological strategies. While the role of leaf P fractions in photosynthesis has been systematically studied, its role in other functions has received less attention.
Here, we present evidence that inorganic P stored in leaves serves as a resource during fruit development. Through continuous monitoring of Fagus crenata, a deciduous tree species in a temperate forest in Japan, we observed a decline in leaf inorganic P concentration, including P stored in vacuoles, during fruit development. Notably, this decline was absent in non-fruiting individuals, suggesting that leaf inorganic P may act as a crucial P source for reproductive processes in this species.
In this presentation, we will further explore how the reduction in inorganic P is related to the allocation of leaf P to organic P fractions.