Effects of drought on the competitive interference of an early successional species (Rubus fruticosus) on Fagus sylvatica L. seedlings:: 15N uptake and partitioning, responses of amino acids and other N compounds
Effects of drought on the competitive interference of an early successional species (Rubus fruticosus) on Fagus sylvatica L. seedlings:: 15N uptake and partitioning, responses of amino acids and other N compounds
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DOI：
10.1055/s-2002-32334
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发表时间：
2002-05-01
期刊：
影响因子：
3.9
通讯作者：
Gessler, A
中科院分区：
文献类型：
--
作者：
Fotelli, MN;Rennenberg, H;Gessler, A
我们评估的作用，水的可用性作为一个因素调节的能力，山毛榉幼苗，以科普竞争性干扰氮资源的早期演替物种（悬钩子fruticosus）。温室实验进行了两个水平的干扰（山毛榉与R。fruticosus）和三个水平的灌溉（高、中、无）。N-15吸收和分配的两个物种，和N库的组成在叶，根和韧皮部的山毛榉，进行了测定。在所有灌溉条件下，山毛榉幼苗与R. fruticosus。R.在所有供水水平下，灌木比山毛榉具有更高的N-15吸收速率。当灌溉量减少时，山毛榉幼苗对N-15的吸收显著减少，而R. fruticosus观察。R的干扰。灌木丛和低灌溉也影响了N-15在山毛榉幼苗中的分配，并导致N-15分配到根部的减少。竞争性干扰和缺乏灌溉的组合导致了水溶性非蛋白氮在根和叶的山毛榉，由于蛋白质降解的增加。这种反应归因于在这些条件下作为抗氧化剂的氨基酸水平的增加。山毛榉叶片脯氨酸含量与地上部水势呈负相关。结果表明：（1）高、中等灌溉条件下，山毛榉叶片全氮含量均表现出竞争性降低。（2）山毛榉幼苗为科普土壤水分减少和R. fruticosus。
We assessed the role of water availability as a factor regulating the ability of beech seedlings to cope with competitive interference for nitrogen resources by an early successional species (Rubus fruticosus). A glasshouse experiment was performed with two levels of interference (beech with and without R. fruticosus) and three levels of irrigation (high, intermediate, none). N-15 uptake and partitioning of both species, and composition of N pools in leaves, roots and phloem of beech, were determined. Under all irrigation regimes, N-15 uptake by beech seedlings decreased when grown together with R. fruticosus. R. fruticosus had higher N-15 uptake rates than beech, under all water supply levels. When irrigation was reduced, a substantial decrease in N-15 uptake of beech seedlings and a concurrent increase in N-15 uptake by R. fruticosus were observed. Interference by R. fruticosus and low irrigation also affected the N-15 partitioning in beech seedlings and resulted in reduced allocation of N-15 to the roots. The combination of competitive interference and lack of irrigation led to an increase in soluble non-protein N in roots and leaves of beech, due to protein degradation. This response was attributed to an increase in levels of amino acids serving as osmoprotectants under these conditions. The concentration of proline in leaves of beech was negatively correlated to shoot water potential. A competition-induced reduction of total N in leaves of beech under high and intermediate irrigation was found. These results illustrate (1) the advantage of R. fruticasus in terms of N uptake when compared to young beech, particularly under inadequate water supply, and (2) the changes in IN composition of beech seedlings in order to cope with reduced soil water and interference by R. fruticosus.