文献类型：期刊文献

英文题名：Physiological characteristics and RNA sequencing in two root zones with contrasting nitrate assimilation of Populus x canescens

作者：Zhou, Jing[1] Lu, Yan[1] Shi, Wen-Guang[1] Deng, Shu-Rong[1] Luo, Zhi-Bin[1]

第一作者：周婧

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

年份：2020

卷号：40

期号：10

起止页码：1392-1404

外文期刊名：TREE PHYSIOLOGY

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000607844100007)】；

基金：This work was supported by the National Natural Science Foundation of China (Grant nos 31500507 and 31670609) and the Fundamental Research Funds for the Central Non-profit Research Institution of CAF (grant no. CAFYBB2016QB005).

语种：英文

外文关键词：miRNAs; net NO3- flux; nitrate; poplar; root zones

摘要：Different root zones have distinct capacities for nitrate (NO3-) uptake in Populus species, but the underlying physiological and microRNA (miRNA) regulatory mechanisms remain largely unknown. To address this question, two root zones of Populus x canescens (Ait.) Smith. with contrasting capacities for NO3- uptake were investigated. The region of 040 mm (root zone I) to the root apex displayed net influxes, whereas the region of 40-80 mm (root zone II) exhibited net effluxes. Concentrations of NO3- and ammonium (NH4+) as well as nitrate reductase activity were lower in zone II than in zone I. Forty one upregulated and twenty three downregulated miRNAs, and 576 targets of these miRNAs were identified in zone II in comparison with zone I. Particularly, growth-regulating factor 4 (GRF4), a target of upregulated ptcmiR396g-5p and ptc-miR396f_L + 1R-1, was downregulated in zone II in comparison with zone I, probably contributing to lower NO3- uptake rates and assimilation in zone II. Furthermore, several miRNAs and their targets, members of C2H2 zinc finger family and APETALA2/ethylene-responsive element binding protein family, were found in root zones, which probably play important roles in regulating NO3- uptake. These results indicate that differentially expressed miRNA-target pairs play key roles in regulation of distinct NO3- uptake rates and assimilation in different root zones of poplars.