Leaf enzyme plays a more important role in leaf nitrogen resorption efficiency than soil properties along an elevation gradient
Leaf enzyme plays a more important role in leaf nitrogen resorption efficiency than soil properties along an elevation gradient
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叶酶在叶片氮吸收效率中的作用比沿海拔梯度的土壤特性更重要
DOI：
10.1111/1365-2745.13971
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发表时间：
2022
影响因子：
5.5
通讯作者：
Edith Bai
中科院分区：
文献类型：
--
作者：
Bai Liu;Decai Gao;Qing Chang;Ziping Liu;Xianlei Fan;Di Meng;Edith Bai
氮素再吸收是植物在凋落物之前从衰老叶片中吸收氮素的一种保存策略，其机制对于理解氮素循环具有重要意义。然而，目前的研究主要集中在土壤和叶片养分对叶片氮再吸收效率（NRE）的影响，植物生理调控的物种依赖性尚不清楚。本文通过野外试验研究了中国东北温带森林植物叶片NRE沿着海拔梯度的变化。结果表明，蒙古栎和水曲柳叶片NRE随海拔升高而增加，紫椴、色木槭和拟花槭叶片NRE随海拔升高而增加，但紫椴叶片NRE与海拔的相关性不显著。mandshurica和A.单核细胞增多症不同物种叶片NRE对海拔升高的不一致反应主要是由于叶片谷氨酸脱氢酶（GDH）的影响，这是一种负责氮转运的酶。衰老叶片GDH活性对氮素利用率的解释能力强于土壤和气候因子，说明在相似的环境条件下，不同植物对氮素利用的生理调控策略不同。合成.我们的研究突出了叶酶作为叶片NRE的关键调节剂的作用，并帮助我们更好地了解和预测气候变化下的森林生态系统中的N循环。
Nitrogen (N) resorption is a strategy for plant N conservation through which plants withdraw N from senescing leaves prior to litterfall and its underlying mechanisms are important for better understanding of N cycling. However, most current studies focused on the impacts of soil and leaf nutrients on leaf N resorption efficiency (NRE), and plant physiological regulation that is species dependent is still unclear. Here, we conducted a field experiment to investigate the variations of leaf NRE along an altitudinal gradient in a temperate forest of Northeastern China. Results showed that leaf NRE of Quercus mongolica and Fraxinus mandshurica increased with altitude, while leaf NRE of Tilia amurensis, Acer mono and Acer pseudosieboldianum exhibited an opposite trend, although the relationships were not significant for F. mandshurica and A. mono. The inconsistent responses of leaf NRE of different species to increasing altitude were primarily due to the effect of leaf Glutamate dehydrogenase (GDH), an enzyme responsible for N translocation. Leaf GDH activity in senescing leaves explained the variation of NRE more than soil and climate factors did, suggesting that different plant species had different physiological regulation strategies for their N conservation under similar environment. Synthesis. Our study highlights the role of leaf enzyme as a pivotal regulator of leaf NRE and helps us better understand and predict N cycling under climate change in forest ecosystems.