Crop domestication increased photosynthetic phosphorus-use efficiency associated with changes in leaf phosphorus fractions under low soil phosphorus conditions

The domestication of modern crop cultivars involved significant changes in key agronomic traits relative to their wild relatives. This study aimed to investigate the effects of crop domestication on leaf phosphorus (P)-use strategies, particularly photosynthetic P-use efficiency (PPUE), under low plant-available soil P conditions.

Ten crop species and their wild relatives were grown in pots under low plant-available soil P conditions to compare leaf PPUE, the concentration and percentage of five leaf P fractions, and investigate the correlation of these P fractions with PPUE.

Domesticated crops exhibited significantly higher area-based (A_area) and mass-based (A_mass) photosynthesis rate, and PPUE (63%, 74% and 69%, respectively) than their wild relatives under low plant-available P condition. Domesticated crops demonstrated a 49% higher metabolite-P concentration but an 18% lower lipid-P concentration than their wild relatives. Domestication significantly reduced P allocation to lipid-P (20%) and inorganic-P (9%), coupled with increased partitioning to metabolite-P (67%) and residual-P (43%). PPUE was positively correlated with A_area, A_mass, metabolite-P concentration, and the percentage of leaf P allocated to the metabolite-P fraction, while being negatively correlated with leaf P concentration, nucleic acid-P, inorganic-P concentration, and the percentage of leaf P allocated to inorganic-P fraction.

Crop domestication enhanced PPUE by increased photosynthesis rates and a shift in leaf P allocation to different P fractions. Greater allocation to P-containing metabolites but reduced investment in inorganic P provide crucial mechanistic insights for enhanced PPUE under P-limited condition, unravelling strategies aimed at improving crop P-use efficiency under low-limited environment.