文献类型：期刊文献

英文题名：Phenylalanine as a nitrogen source induces root growth and nitrogen-use efficiency in Populus x canescens

作者：Jiao, Yu[1] Chen, Yinghao[1] Ma, Chaofeng[1] Qin, Jingjing[2] Thi Hong Nhung Nguyen[1] Liu, Di[1] Gan, Honghao[2] Ding, Shen[1] Luo, Zhi-Bin[3]

第一作者：Jiao, Yu

通信作者：Luo, ZB[1]

机构：[1]Northwest A&F Univ, Coll Forestry, Yangling 712100, Shaanxi, Peoples R China;[2]Northwest A&F Univ, Coll Life Sci, Yangling 712100, Shaanxi, Peoples R China;[3]Chinese Acad Forestry, State Key Lab Tree Genet & Breeding, Key Lab Silviculture, State Forestry Adm,Res Inst Forestry, Beijing 100091, Peoples R China

年份：2018

卷号：38

期号：1

起止页码：66-82

外文期刊名：TREE PHYSIOLOGY

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000422839600006)】；

基金：This research was jointly supported by the State Key Basic Research Development Program (Grant No. 2012CB416902), the National Natural Science Foundation of China (Grant Nos. 31270647, 31470618 and 31670609), and the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20130204110012).

语种：英文

外文关键词：amino acids; aromatic and neutral amino acids transporter; nitrogen-use efficiency; organic nitrogen; phenylalanine; phenylalanine ammonia lyase; root characteristics; transcriptional regulation

摘要：To investigate the physiological responses of poplars to amino acids as sole nitrogen (N) sources, Populus x canescens (Ait.) Smith plants were supplied with one of three nitrogen fertilizers (NH4NO3, phenylalanine (Phe) or the mixture of NH4NO3 and Phe) in sand culture. A larger root system, and decreased leaf size and CO2 assimilation rate was observed in Phe-versus NH4NO3-treated poplars. Consistently, a greater root biomass and a decreased shoot growth were detected in Phe-supplied poplars. Decreased enzymatic activities of nitrate reductase (NR), glutamate synthase (GOGAT) and glutamate dehydrogenase (GDH) and elevated activities of nitrite reductase (NiR), phenylalanine ammonia lyase (PAL), glutamine synthetase (GS) and asparagine synthase (AS) were found in Phe-treated roots. Accordingly, reduced concentrations of NH4+, NO3 -and total N, and enhanced N-use efficiencies (NUEs) were detected in Phe-supplied poplars. Moreover, the transcript levels of putative Phe transporters ANT1 and ANT3 were up-regulated, and the mRNA levels of NR, glutamine synthetase 2 (GS2), NADH-dependent glutamate synthase (NADH-GOGAT), GDH and asparagine synthetase 2 (ASN2) were downexpressed in Phe-treated roots and/ or leaves. The 15N-labeled Phe was mainly allocated in the roots and only a small amount of 15N-Phe was translocated to poplar aerial parts. These results indicate that poplar roots can acquire Phe as an N source to support plant growth and that Phe-induced NUEs in the poplars are probably associated with NH4+ re-utilization after Phe deamination and the carbon bonus simultaneously obtained during Phe uptake.