Plasticity of functional traits and optimality of biomass allocation in elevational ecotypes of Arabidopsis halleri grown at different soil nutrient availabilities
Plasticity of functional traits and optimality of biomass allocation in elevational ecotypes of Arabidopsis halleri grown at different soil nutrient availabilities
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DOI：
10.1007/s10265-019-01088-9
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发表时间：
2019-02
影响因子：
2.8
通讯作者：
Qing-Wei Wang;Maya Daumal;S. Nagano;Naofumi Yoshida;S. Morinaga;K. Hikosaka
中科院分区：
文献类型：
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作者：
Qing-Wei Wang;Maya Daumal;S. Nagano;Naofumi Yoshida;S. Morinaga;K. Hikosaka
在山区，植物的分布受到各种环境胁迫的制约。植物功能性状的可塑性和稳定性可能与不同生境的最优策略和沿海拔方向的生态型分化有关。虽然植物生物量分配已被广泛研究与适应土壤养分有效性沿海拔，其最优性仍然知之甚少。研究了大田土壤养分有效性，并对不同养分有效性条件下生长的2个海拔生态型拟南芥进行了生长分析。我们确定了形态和生理性状的可塑性，并利用最优性模型评估了最佳生物量分配。野外调查结果表明，随着海拔的升高，土壤氮素有效性呈上升趋势，而不是下降趋势。生长分析表明，低地生态型在形态变量和氮浓度上具有较强的可塑性，而高原生态型在净同化率（NAR）等生理变量上具有较强的可塑性。在全N效度范围内，低地生态型的叶质量比具有中等可塑性，而高原生态型的叶质量比仅在高N效度范围内具有很强的可塑性。最优性模型表明，在研究的氮有效度范围内，低地生态型的LMR接近最优，而在低氮有效度范围内，高原生态型的LMR为次优。这些结果表明，高原生态型只适应于高氮有效度，而低地生态型则适应于相对广泛的氮有效度，这是其栖息地自然选择的结果。我们认为，两种生态型之间存在着适应性分化，生物量分配的可塑性与其在变化环境下的优化直接相关。
In mountainous areas, plant distribution is constrained by various environmental stresses. Plasticity and constancy in plant functional traits may relate to optimal strategies at respective habitats and to ecotypic differentiation along elevation. Although plant biomass allocation has been extensively studied in relation to adaptation to soil nutrient availability along elevation, its optimality is still poorly understood. We examined soil nutrient availability in the field and conducted growth analysis for two elevational ecotypes ofArabidopsis hallerigrown under different nutrient availabilities. We determined plasticity in morphological and physiological traits and evaluated optimal biomass allocation using an optimality model. Our field investigation indicated that soil nitrogen (N) availability increased rather than decreased with increasing elevation. Our growth analysis revealed that lowland ecotype was more plastic in morphological variables and N concentrations, whereas the highland ecotype was more plastic in other physiological variables such as the net assimilation rate (NAR). The leaf mass ratio (LMR) in the lowland ecotype was moderately plastic at the whole range of N availabilities, whereas LMR in the highland ecotype was very plastic at higher N availabilities only. The optimality model indicated that the LMR of the lowland ecotype was nearly optimal throughout the range of studied N availabilities, whereas that of the highland ecotype was suboptimal at low N availability. These results suggest that highland ecotype is adapted only to high N availability, whereas the lowland ecotype is adapted to a relatively wide range of N availabilities as a result of natural selection in their respective habitats. We conclude that an adaptive differentiation has occurred between the two ecotypes and plasticity in the biomass allocation is directly related to its optimization in changing environments.