Nature. 1990 Mar 1;344(6261):58-60. doi: 10.1038/344058a0.
SOIL microsites rich in available nutrients are an important source of mineral nutrients for plants in many environments(1-5). Patchiness in nutrient availability below ground is analogous to resource availability in canopy gaps above ground(6). Although the physiological changes occurring in leaves exposed to sun and shade in canopy gaps are well known(7-9), we do not know any studies that show similar physiological changes in roots in enriched soil patches. Here we present evidence of large and rapid increases in the uptake kinetics of plant roots after creating nutrient-rich soil patches in the field. The mean rate of phosphate uptake at a given external phosphate concentration increased by as much as 80% for roots from enriched soil patches compared with roots of control patches treated with distilled water. The changes took place within days of patch treatment. This degree of plasticity was particularly notable for plants growing in soils of very low available phosphorus. These results showing rapid physiological plasticity of roots in fertile soil microsites have important implications for the theory and modelling of nutrient uptake in all soils.
土壤微域中富含可利用养分，是许多环境中植物矿物质养分的重要来源(1-5)。地下养分可利用性的斑块状分布类似于地上冠层空隙中资源的可利用性(6)。虽然叶片在冠层空隙中暴露于阳光和阴凉处时发生的生理变化众所周知(7-9)，但我们不知道任何研究表明在富含有机质的土壤斑块中根系会发生类似的生理变化。在这里，我们提供了在野外创造富含养分的土壤斑块后，植物根系吸收动力学发生大幅快速增加的证据。与用蒸馏水处理的对照斑块中的根系相比，来自富营养斑块的根系在给定的外部磷酸盐浓度下吸收磷酸盐的平均速率增加了多达 80%。这些变化发生在斑块处理后的几天内。对于在土壤有效磷含量非常低的土壤中生长的植物来说，这种可塑性程度尤为显著。这些结果表明，在肥沃的土壤微域中，根系具有快速的生理可塑性，这对所有土壤中养分吸收的理论和模型化具有重要意义。
