Biomass allocation and leaf chemical defence in defoliated seedlings of Quercus serrata with respect to carbon-nitrogen balance
Biomass allocation and leaf chemical defence in defoliated seedlings of Quercus serrata with respect to carbon-nitrogen balance
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DOI：
10.1093/aob/mci111
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发表时间：
2005-05-01
期刊：
影响因子：
4.2
通讯作者：
Kamata, N
中科院分区：
文献类型：
--
作者：
Hikosaka, K;Takashima, T;Kamata, N
背景和目的养分的有效性和落叶影响植物的碳-养分平衡，这反过来又影响生物量分配（如茎-根比）和叶的化学组成（氮和次生化合物的浓度）。在这项研究中，它是质疑是否落叶改变生物量分配和化学防御在类似的方式来应对nutrientdeficiency.Methods当年苗的锯齿栎生长与或不去除所有的叶子在三个水平的养分availability.Key Results植物氮浓度（PNC），在植物中的碳-养分平衡的措施，在落叶后立即显著降低，因为叶具有比茎和根更高的氮浓度。然而，PNC恢复到类似于或高于对照植物的水平，在3或6周后的落叶。去叶后产生的叶片氮浓度显著高于对照叶片。单株叶质量（叶质量比，LMR）与PNC呈显著正相关，但脱叶植株与对照植株的关系存在显著差异。当在相同PNC下比较时，落叶植物具有较低的LMR。然而，脱叶后新产生的根组织的比例作为PNC的函数在脱叶和对照植物之间没有差异。落叶植物有一个显着较低的总酚和缩合单宁的浓度。在落叶和对照植物，叶单宁浓度与叶氮浓度呈负相关，这表明碳基防御化合物的量控制的碳-养分平衡在leaflevel.Conclusions落叶改变生物量分配和化学防御，通过在植物和叶片水平的碳-养分平衡。
Background and Aims Both nutrient availability and defoliation affect the carbon-nutrient balance in plants, which in turn influences biomass allocation (e.g. shoot-to-root ratio) and leaf chemical composition (concentration of nitrogen and secondary compounds). In this study it is questioned whether defoliation alters biomass allocation and chemical defence in a similar fashion to the response to nutrient deficiency.Methods Current-year seedlings of Quercus serrata were grown with or without removal of all leaves at three levels of nutrient availability.Key Results Plant nitrogen concentration (PNC), a measure of the carbon-nutrient balance in the plant, significantly decreased immediately after defoliation because leaves had higher nitrogen concentrations than stems and roots. However, PNC recovered to levels similar to or higher than that of control plants in 3 or 6 weeks after the defoliation. Nitrogen concentration of leaves produced after defoliation was significantly higher than leaf nitrogen concentration of control leaves. Leaf mass per plant mass (leaf mass ratio, LMR) was positively correlated with PNC but the relationship was significantly different between defoliated and control plants. When compared at the same PNC, defoliated plants had a lower LMR. However, the ratio of the leaf to root tissues that were newly produced after defoliation as a function of PNC did not differ between defoliated and control plants. Defoliated plants had a significantly lower concentration of total phenolics and condensed tannins. Across defoliated and control plants, the leaf tannin concentration was negatively correlated with the leaf nitrogen concentration, suggesting that the amount of carbon-based defensive compounds was controlled by the carbon-nutrient balance at the leaf level.Conclusions Defoliation alters biomass allocation and chemical defence through the carbon-nutrient balance at the plant and at the leaf level, respectively.