# Differential Phosphorus Acquisition Strategies and Adaptive Mechanisms Evolved by Three Lespedeza Species to Tackle Phosphorus Deficiency

## TL;DR

This study explores how three Lespedeza species adapt to phosphorus-deficient soils through different strategies, with L. bicolor showing the most efficient mechanisms.

## Contribution

The paper reveals distinct phosphorus acquisition strategies and adaptive mechanisms in three Lespedeza species under phosphorus deficiency.

## Key findings

- L. davurica and L. bicolor allocate more biomass to roots under P deficiency, while L. cuneata increases specific root length and area.
- L. bicolor shows higher phosphorus content in stems and leaves and the strongest P affinity and acquisition capacity.
- L. bicolor exudates are enriched in acid phosphatase activity, while L. davurica and L. cuneata secrete more organic acids.

## Abstract

Phosphorus (P) is essential for plant growth but is frequently limited in soils. Lespedeza species are well-known for their ecological and economic benefits, as well as their tolerance to nutrient-poor soils. This study investigated the P acquisition strategies and adaptive mechanisms of three Lespedeza species (L. davurica, L. bicolor, and L. cuneata), focusing on biomass allocation, P distribution, root exudation, and absorption kinetics under P deficiency. Under P deficiency, L. davurica and L. bicolor allocated more biomass to roots to enhance P acquisition, whereas L. cuneata increased specific root length and area. Moreover, all three species preferentially allocated P to roots, but L. bicolor showed higher P content in stems and leaves than the others. P absorption kinetics indicated that Michaelis constant (Km) and equilibrium concentration (Cmin) were significantly decreased in all three species under P deficiency, with L. bicolor exhibiting the strongest P affinity and acquisition capacity. Secretion analysis revealed that while L. davurica and L. cuneata secreted higher levels of organic acids under P deficiency, exudates from L. bicolor were significantly enriched in acid phosphatase activity. Overall, the three Lespedeza species developed distinct P acquisition and adaptive strategies to cope with P deficiency, with L. bicolor demonstrating the greatest low-P tolerance and most efficient adaptive mechanisms.