Amino acids as a nitrogen source in temperate upland grasslands: the use of dual labelled ((13)C, (15)N) glycine to test for direct uptake by dominant grasses.
Amino acids as a nitrogen source in temperate upland grasslands: the use of dual labelled ((13)C, (15)N) glycine to test for direct uptake by dominant grasses.
复制标题
DOI：
10.1002/1097-0231(20000815)14:15
复制
发表时间：
2000-08
期刊：
影响因子：
--
通讯作者：
T. Streeter;R. Bol;R. Bardgett
中科院分区：
文献类型：
--
作者：
T. Streeter;R. Bol;R. Bardgett
越来越明显的是，土壤氨基酸是某些植物，特别是那些氮有限的环境中的氮（N）的主要来源。本研究利用甘氨酸-2-（13）C-（15）N和（15）NH_4）_2SO_4标记技术对温带高地草原进行了研究，以检验占主导地位的植物种“未改良”半天然草原的假设，（Festuca-Agrostis-Galium）能够利用氨基酸N进行生长，而那些在“改良”草原上占主导地位的植物（Lolium-Cynosurus），定期施用无机肥料，使用无机N形式作为其主要的N源。田间试验数据证实，“游离”氨基酸更丰富的“未改良”比“改良”草地和甘氨酸是占主导地位的氨基酸类型（高达42%）。其次，注射的代表性量的甘氨酸-2-（13）C-（15）N（4.76和42.86毫米）到完整的土壤芯从两个草原类型提供的证据直接吸收甘氨酸的植物，与（15）N和（13）C被检测到在植物材料的两个草原。最后，一个微观实验表明，没有优先吸收氨基酸N的草占主导地位的草地类型，即Holcus lanatus，紫羊茅，剪股颖从“未改良”的草地，和多年生黑麦草从“改良”的草地。同样，（13）C和（15）N在所有草类中均被检测到，表明这些植物吸收了完整的甘氨酸。
It is becoming increasingly apparent that soil amino acids are a principal source of nitrogen (N) for certain plants, and especially those of N-limited environments. This study of temperate upland grasslands used glycine-2-(13)C-(15)N and ((15)NH4)(2)SO(4) labelling techniques to test the hypothesis that plant species which dominate 'unimproved' semi-natural grasslands (Festuca-Agrostis-Galium) are able to utilise amino acid N for growth, whereas those plants which dominate 'improved' grasslands (Lolium-Cynosurus), that receive regular applications of inorganic fertiliser, use inorganic N forms as their main N source. Data from field experiments confirmed that 'free' amino acids were more abundant in 'unimproved' than 'improved' grassland and that glycine was the dominant amino acid type (up to 42% of total). Secondly, the injection of representative amounts of glycine-2-(13)C-(15)N (4.76 and 42.86 mM) into intact soil cores from the two grassland types provided evidence of direct uptake of glycine by plants, with both (15)N and (13)C being detected in plant material of both grasslands. Finally, a microcosm experiment demonstrated no preferential uptake of amino acid N by the grasses which dominate the grassland types, namely Holcus lanatus, Festuca rubra, Agrostis capillaris from the 'unimproved' grassland, and Lolium perenne from the 'improved' grassland. Again, both (13)C and (15)N were detected in all grass species suggesting uptake of intact glycine by these plants.