Physiological responses of bryophytes Thuidium tamariscinum and Hylocomium splendens to increased nitrogen deposition
Physiological responses of bryophytes Thuidium tamariscinum and Hylocomium splendens to increased nitrogen deposition
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DOI：
10.1093/aob/mcl239
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发表时间：
2007-01-01
期刊：
影响因子：
4.2
通讯作者：
Richter, A.
中科院分区：
文献类型：
--
作者：
Koranda, M.;Kerschbaum, S.;Richter, A.
背景和目的氮沉降水平的增加导致许多britonite物种的N含量增加和生产力降低。本研究旨在阐明氮素吸收增加导致黑藻生长下降的机制，重点研究氮素添加对黑藻碳代谢的影响（氮负荷等于30 kg ha（-1）a（-1））80 d，包括用（CO2）-C-关键结果：T tamarcinum的生长不受N添加的影响，而H.一串红表现出生长减少的趋势。施氮显著提高了H.结果表明，在不同的生长阶段，Tamburcinum的氨基酸-N含量均显著增加，而Tamburcinum的氨基酸-N含量仅显著增加。在两种植物中，均观察到脂类浓度的降低、最大碳库的形成以及受精植物碳库周转率的显著提高。高水平氮沉积下的千里光可能是由含氮有机化合物（最有可能是细胞壁蛋白质）合成增强引起的。细胞碳代谢的紊乱，如碳库周转的增强所示，可能进一步导致H生产力的下降。灿烂。
Background and Aims Increased levels of nitrogen (N) deposition lead to enhanced N contents and reduced productivity of many bryophyte species. This study aimed at elucidating the mechanisms by which enhanced N uptake may cause growth reduction of bryophytes, focusing on the effects of N addition on carbon (C) metabolism of bryophytes.Methods Plantlets of Thuidium tamariscinum and Hylocomium splendens were fertilized with NH4NO3 (N load equalling 30 kg ha(-1) year(-1)) for 80 d, including a pulse labelling experiment with (CO2)-C-13 to dissect the partitioning of carbon in response to N addition.Key Results Growth of T tamariscinum was not affected by N addition, while H. splendens showed a trend towards growth reduction. Total N concentration was significantly increased by N addition in H. splendens, a significant increase in amino acid-N was found in T tamariscinum only. In both bryophyte species, a reduction in concentration of lipids, the greatest C storage pool, as well as markedly enhanced turnover rates of C storage pools in fertilized plants were observed.Conclusions The results suggest that growth reduction of H. splendens under high levels of N deposition may be caused by enhanced synthesis of N-contaiming organic compounds, most probably of cell wall proteins. Disturbance of cellular C metabolism, as indicated by enhanced C pool turnover, may further contribute to the decline in productivity of H. splendens.