Photosynthesis or persistence:: nitrogen allocation in leaves of evergreen and deciduous Quercus species
Photosynthesis or persistence:: nitrogen allocation in leaves of evergreen and deciduous Quercus species
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DOI：
10.1111/j.1365-3040.2004.01209.x
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发表时间：
2004-08-01
影响因子：
7.3
通讯作者：
Hirose, T
中科院分区：
文献类型：
--
作者：
Takashima, T;Hikosaka, K;Hirose, T
光合氮素利用效率(PNUE，单位叶氮的光合作用能力)是造成光合作用能力种间差异的重要因素之一。对栎属两个常绿种和两个落叶种的PNUE进行了分析。常绿植物的PNUE低于落叶植物，这主要归因于常绿植物中分配给光合器的氮素比例较小。进一步分析了叶片氮在水溶组分、洗涤剂可溶组分和洗涤剂不溶组分中的蛋白质。假定洗涤剂不溶于水的蛋白质代表细胞壁蛋白质。常绿植物中分配给洗涤剂不溶蛋白质的氮素比例大于落叶植物。因此，在常绿植物中，氮素分配到光合器的较少与分配到细胞壁的较多有关。在不同物种中，洗涤剂不溶性蛋白中的氮含量与单位面积叶质量呈正相关，而光合作用蛋白中的氮含量与单位面积叶质量呈负相关。氮的分配在与生产力有关的成分(光合作用蛋白质)和与持久性有关的成分(结构蛋白质)之间可能存在权衡。这种权衡可能导致叶片性状的趋同，其中叶片寿命较长的物种具有更大的单位面积叶质量，较低的光合作用能力，以及较低的PNUE，无论其生活型、系统发育和生物群如何。
Photosynthetic nitrogen use efficiency (PNUE, photosynthetic capacity per unit leaf nitrogen) is one of the most important factors for the interspecific variation in photosynthetic capacity. PNUE was analysed in two evergreen and two deciduous species of the genus Quercus. PNUE was lower in evergreen than in deciduous species, which was primarily ascribed to a smaller fraction of nitrogen allocated to the photosynthetic apparatus in evergreen species. Leaf nitrogen was further analysed into proteins in the water-soluble, the detergent-soluble, and the detergent-insoluble fractions. It was assumed that the detergent-insoluble protein represented the cell wall proteins. The fraction of nitrogen allocated to the detergent-insoluble protein was greater in evergreen than in deciduous leaves. Thus the smaller allocation of nitrogen to the photosynthetic apparatus in evergreen species was associated with the greater allocation to cell walls. Across species, the fraction of nitrogen in detergent-insoluble proteins was positively correlated with leaf mass per area, whereas that in the photosynthetic proteins was negatively correlated. There may be a trade-off in nitrogen partitioning between components pertaining to productivity (photosynthetic proteins) and those pertaining to persistence (structural proteins). This trade-off may result in the convergence of leaf traits, where species with a longer leaf life-span have a greater leaf mass per area, lower photosynthetic capacity, and lower PNUE regardless of life form, phyllogeny, and biome.