植物营养与肥料学报2017，Vol.23Issue(1)：189-195,7.DOI:10.11674/zwyf.16067
茶树对可溶性有机和无机态氮的吸收与运转特性
Uptake and transport characteristics of soluble organic and inorganic nitrogen by tea plant
摘要
Abstract
[Objectives] Whether tea plants in subtropics could directly take up soluble molecular organic nitrogen from soil or not does not have agreeable conclusions.Studying the transport charecteristics of soluble organic and inorganic nitrogen in tea plants will help the deep understanding of the problem.[Methods] The isotope tracing method was used in a pot experiment using tea seedlings (Huangjingui) as tested material.The isotope tracers were 2-13C-15N-glycine,(15NH4)2SO4 and 15N-KNO3,which were injected into soil at the bottom of tea seedlings.Aboundance of 13C and 15N in shoots and roots were measured by isotope ratio mass spectrometer with a Eurovector Elemental Analyser.[Results] The ratios of 13C to 15N excess in roots and whole seedlings of Huangjingui were much close to 1 ∶ 1,the theroretical ratio of 13C to 15N aboundance,at 2 h and 6 h after the 2-13C-15N-glycine application in soil.The 13C excess was not detected in Huangjingui shoots at 2 h and 6 h,while it reached 0.284 μmol/(g,DW) in shoots at 72 h after the 2-13C-15N-glycine application.The 15N excesses of roots,shoots and whole seedlings of Huangjingui at 2 h,6 h and 72 h after the (15NH4)2SO4 application were significantly higher than those after the 15N-KNO3 and 2-13C-15N-glycine application in soil.The shoot/root ratio in 15N excess at 6 h after the (15NH4)2SO4 application was 34.7％ and 65.0％ higher than those after the 15N-KNO3 and 2-13C-15N-glycine application,while the ratio at 72 h after the (15NH4)2SO4 application was 88.6％ and 133.0％ higher than those after the 15N-KNO3 and 2-13C-15N-glycine application,respectively,and the differences of the ratios between the (15NH4)2SO4 and 15N-KNO3 or 2-13C-15N-glycine treatments reached the 1％ level.[Conclusions] Tea plants of Huangjingui could directly take up intact glycine molecule from the soil,but preferred to uptake ammonium-N and nitrate-N.The glycine molecule taken up by Huangjingui could be transported from roots to shoots.The transport ability of different forms of nitrogen in Huangjingui plants showed following order:ammonium-N ＞ nitrate-N ＞ glycine-N.These results provided further evidence that uptake of soluble organic N by plants is a widespread adaptation strategy in terrestrial ecosystems.关键词
同位素双标记示踪法/茶树/13C、15N标记甘氨酸/吸收/运转Key words
isotopic double marking tracer method/tea plant/2-13C-15N-glycine/uptake/transport引用本文复制引用
周碧青,陈成榕,杨文浩,张黎明,邢世和..茶树对可溶性有机和无机态氮的吸收与运转特性[J].植物营养与肥料学报,2017,23(1):189-195,7.基金项目
国家自然科学基金面上项目(31170485) （31170485）
福建省自然科学基金项目(2015J01090)资助. （2015J01090）
