Abstract
Phosphorus (P) is among the most intractable constraints on plant fertility, particularly in acidic soils with high P fixation capacities. The effects of nutrient limitation and the adaptive strategies of plants in infertile soils are central topics in plant ecology. The development of tree cultivars with greater P use efficiency (PUE), defined as the ability of a tree to grow and be productive in soils with reduced P availability, would substantially improve forest development. The ability of plants to redistribute and transfer P across fractions determines their adaptability to P limitations. However, the mechanisms of P utilization and transport remain unknown in Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) from the perspective of P fraction distribution. In this study, we investigated the distribution and translocation patterns of exogenous P and different P fractions in the M1 Chinese fir, which was identified as exhibiting high P-deficient resistance ability and maintaining higher yield under low P stress relative to the average clones, using 32P tracking, which can accurately trace the migration pathways of exogenous P after plant absorption. We found that exogenous P in the roots was higher than in the stems or leaves under low-P conditions in which the amount of the exogenous P absorbed by M1 was significantly reduced. Under low-P conditions, the plants optimized P allocation, which led to higher PUE than under high-P conditions, with the highest PUE in the leaves, followed by the stems and roots. The M1 clone maintained a high ratio of soluble P (i.e., inorganic P and ester P) in its leaves and stems, which improved P mobility and recycling under the conditions of limited P. In the roots, the P fractions shifted from soluble inorganic P and ester P to insoluble P (i.e., nucleic P), but the total P concentration was relatively stable, which may ensure root growth and exogenous P absorption under the conditions of limited P. Our results confirm that the M1 Chinese fir reduces P demand, optimizes the allocation of P among P fractions, and increases PUE to maintain aboveground productivity in response to limited P conditions.
Funder
National Natural Science Foundation of China
Natural Science Foundation of Fujian Province
Start-up Project of Introducing High-level Talents of Nanchang Institute of Technology
Cited by
1 articles.
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