Internal remobilization of carbohydrates, lipids, nitrogen and phosphorus in the Mediterranean evergreen oak Quercus ilex
Internal remobilization of carbohydrates, lipids, nitrogen and phosphorus in the Mediterranean evergreen oak Quercus ilex
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DOI：
10.1093/treephys/21.1.9
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发表时间：
2001-01-01
期刊：
影响因子：
4
通讯作者：
Rambal, S
中科院分区：
文献类型：
--
作者：
Cherbuy, B;Joffre, R;Rambal, S
内部资源的再动员是使植物部分独立于外部养分供应的重要机制。研究了地中海栎成熟常绿落叶枝的木本组织和叶面组织在生长期的资源再动员。我们比较了发芽前（3月）和生育期末（7月）叶片和茎中的非结构性碳水化合物、脂质、氮和磷库。我们还通过实验去叶来确定老叶的储存功能。春季叶片和茎中碳化合物库的变化及其对落叶的响应表明，叶片和木本组织可以提供碳来支持茎的生长。与茎龄无关，可溶性糖和脂库在春季显著下降。3月至7月间叶池的变化涉及除淀粉外的所有化合物，并伴有平均叶片生物量下降5%。在同一时期，15%的氮和25%的磷从叶片中去除。相比之下，木质组织不重新动员氮和磷。我们的研究结果支持了先前的假设，即常绿物种的叶子在资源再动员中起主要作用。
Remobilization of internal resources is an important mechanism enabling plants to be partly independent of external nutrient availability. We assessed resource remobilization during the growing period in woody and foliar tissues of leary branches of mature evergreen Mediterranean oak (Quercus ilex L.) at three field sites. We compared nonstructural carbohydrates, lipids, nitrogen and phosphorus pools in leaves and stems before bud burst (March) and at the end of the growing period (July). We also experimentally defoliated leafy branches to determine the storage function of old leaves. Changes in pools of carbon compounds in leaves and stems during spring and in response to defoliation indicated that foliar and woody tissues could provide carbon to support shoot growth. Independently of stem age, soluble sugar and lipid pools decreased significantly during spring. Changes in leaf pools between March and July involved all compounds measured except starch and were accompanied by a 5% decrease in mean leaf biomass. During the same period, 15% of the nitrogen and 25% of the phosphorus were removed from leaves. In contrast, woody tissues did not remobilize nitrogen or phosphorus. Our results support earlier hypotheses that leaves of evergreen species have a primary role in resource remobilization.