Yan Zhengbing, Eziz Anwar, Tian Di, Li Xiuping, Hou Xinghui, Peng Huiyuan, Han Wenxuan, Guo Yalong, Fang Jingyun
Department of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing, China.
College of Life Sciences, Capital Normal University, Beijing, China.
Front Plant Sci. 2019 May 14;10:598. doi: 10.3389/fpls.2019.00598. eCollection 2019.
Allocation of biomass to different organs is a fundamental aspect of plant responses and adaptations to changing environmental conditions, but how it responds to nitrogen (N) and phosphorus (P) availability remains poorly addressed. Here we conducted greenhouse fertilization experiments using , with five levels of N and P additions and eight repeat experiments, to ascertain the effects of N and P availability on biomass allocation patterns. N addition increased leaf and stem allocation, but decreased root and fruit allocation. P addition increased stem and fruit allocation, but decreased root and leaf allocation. Pooled data of the five levels of N addition relative to P addition resulted in lower scaling exponents of stem mass against leaf mass (0.983 vs. 1.226; = 0.000), fruit mass against vegetative mass (0.875 vs. 1.028; = 0.000), and shoot mass against root mass (1.069 vs. 1.324; = 0.001). This suggested that N addition relative to P addition induced slower increase in stem mass with increasing leaf mass, slower increase in reproductive mass with increasing vegetative mass, and slower increase in shoot mass with increasing root mass. Further, the levels of N or P addition did not significantly affect the allometric relationships of stem mass vs. leaf mass, and fruit mass vs. vegetative mass. In contrast, increasing levels of N addition increased the scaling exponent of shoot to root mass, whereas increasing levels of P addition exerted the opposite influence on the scaling exponent. This result suggests that increasing levels of N addition promote allocation to shoot mass, whereas the increasing levels of P addition promote allocation to root mass. Our findings highlight that biomass allocation of exhibits a contrasting response to N and P availability, which has profound implications for forecasting the biomass allocation strategies in plants to human-induced nutrient enrichment.
生物量在不同器官中的分配是植物对不断变化的环境条件作出反应和适应的一个基本方面，但它如何响应氮（N）和磷（P）的有效性仍未得到充分研究。在这里，我们使用[具体植物名称未给出]进行了温室施肥实验，设置了五个氮和磷添加水平以及八次重复实验，以确定氮和磷有效性对生物量分配模式的影响。添加氮增加了叶片和茎的分配，但减少了根和果实的分配。添加磷增加了茎和果实的分配，但减少了根和叶的分配。相对于磷添加，五个氮添加水平的汇总数据导致茎质量与叶质量的缩放指数较低（0.983对1.226；P = 0.000），果实质量与营养体质量的缩放指数较低（0.875对1.028；P = 0.000），地上部质量与根质量的缩放指数较低（1.069对1.324；P = 0.001）。这表明相对于磷添加，氮添加导致随着叶质量增加茎质量增加得较慢，随着营养体质量增加生殖质量增加得较慢，以及随着根质量增加地上部质量增加得较慢。此外，氮或磷添加水平对茎质量与叶质量以及果实质量与营养体质量的异速生长关系没有显著影响。相反，增加氮添加水平增加了地上部与根质量的缩放指数，而增加磷添加水平对缩放指数有相反的影响。这一结果表明，增加氮添加水平促进向地上部质量的分配，而增加磷添加水平促进向根质量的分配。我们的研究结果突出表明，[具体植物名称未给出]的生物量分配对氮和磷有效性表现出相反的响应，这对于预测植物对人为养分富集的生物量分配策略具有深远意义。
