文献类型：期刊文献

英文题名：Physiological Characteristics and Transcriptomic Dissection in Two Root Segments with Contrasting Net Fluxes of Ammonium and Nitrate of Poplar Under Low Nitrogen Availability

作者：Lu, Yan[1] Deng, Shurong[1] Li, Zhuorong[1] Wu, Jiangting[1] Zhu, Dongyue[1] Shi, Wenguang[1] Zhou, Jing[1] Fayyaz, Payam[2] Luo, Zhi-Bin[1]

通信作者：Luo, ZB[1]

机构：[1]Chinese Acad Forestry, Res Inst Forestry, State Key Lab Tree Genet & Breeding, Key Lab Silviculture Natl Forestry & Grassland Ad, Beijing 100091, Peoples R China;[2]Chinese Acad Forestry, Agr & Nat Resources Fac, Forest Range & Watershed Management Dept, Beijing 100091, Peoples R China

年份：2022

卷号：63

期号：1

起止页码：30-44

外文期刊名：PLANT AND CELL PHYSIOLOGY

收录：;Scopus(收录号：2-s2.0-85123877978);WOS:【SCI-EXPANDED(收录号:WOS:000761475400001)】；

基金：This study was jointly supported by the Fundamental Research Funds for the Central Non-profit Research Institutions of CAF (grant no. CAFYBB2019SY013) and the National Key Research and Development Program (grant no. 2016YFD0600105).

语种：英文

外文关键词：Ammonium; Nitrate; Nitrogen deficiency; Populus; Root zone; Uptake

摘要：To investigate physiological and transcriptomic regulation mechanisms underlying the distinct net fluxes of NH4+ and NO3- in different root segments of Populus species under low nitrogen (N) conditions, we used saplings of Populus x canescens supplied with either 500 (normal N) or 50 (low N) mu M NH4NO3. The net fluxes of NH4+ and NO3-, the concentrations of NH4+, amino acids and organic acids and the enzymatic activities of nitrite reductase (NiR) and glutamine synthetase (GS) in root segment II (SII, 35-70 mm to the apex) were lower than those in root segment I (SI, 0-35 mm to the apex). The net NH4+ influxes and the concentrations of organic acids were elevated, whereas the concentrations of NH4+ and NO3- and the activities of NiR and GS were reduced in SI and SII in response to low N. A number of genes were significantly differentially expressed in SII vs SI and in both segments grown under low vs normal N conditions, and these genes were mainly involved in the transport of NH4+ and NO3-, N metabolism and adenosine triphosphate synthesis. Moreover, the hub gene coexpression networks were dissected and correlated with N physiological processes in SI and SII under normal and low N conditions. These results suggest that the hub gene coexpression networks play pivotal roles in regulating N uptake and assimilation, amino acid metabolism and the levels of organic acids from the tricarboxylic acid cycle in the two root segments of poplars in acclimation to low N availability.