Increase of nitrogen to promote growth of poplar seedlings and enhance photosynthesis under NaCl stress  

作　　者：He Wang Huihui Zhang Yushu Liu Jinghong Long Liang Meng Nan Xu Jinbo Li Haixiu Zhong Yining Wu 

机构地区：[1]College of Wildlife Resources,Northeast Forestry University,Harbin 150040,Heilongjiang,People's Republic of China [2]College of Resources and Environment,Northeast Agricultural University,Harbin 150030,Heilongjiang Province,People's Republic of China [3]Natural Resources and Ecology Institute,Heilongjiang Academy of Sciences,Harbin 150040,People's Republic of China [4]Heilongjiang Cold Region Urban-Rural Human Settlements Science Key Laboratory,School of Architecture,Harbin Institute of Technology,Harbin 150001,People's Republic of China

出　　处：《Journal of Forestry Research》2019年第4期1209-1219,共11页林业研究（英文版）

基　　金：supported by the Fundamental Research Funds for the Central Universities(2572018BE05);the National Natural Science Foundation of China(31500323;31370426)

摘　　要：The solution culture method was used to study the effect of increasing nitrogen on the growth and pho-tosynthesis of poplar seedlings under 100 mmol L-1 NaCl stress. I Increase in nitrogen reduced stomatal limitation of leaves under NaCl stress, improved utilization of CO2 by mesophyll cells, enhanced photosynthetic carbon assimi-lation capacity, significantly alleviated saline damage of NaCl, and promoted the accumulation of aboveground and root biomass. I Increased nitrogen enhanced photochemical efficiency (ΦPSⅡ) and electron transport rates, relieved the reduction of maximum photochemical efficiency (Fv/Fm) under NaCl, and reduced the degree of photoinhibition caused by NaCl stress. Increased nitrogen applications reduced the proportion of energy dissipating in the form of ineffective heat energy and hence a greater proportion of light energy absorbed by leaves was allocated to photo-chemical reactions. Under treatment with increased nitro-gen, the synergistic effect of heat dissipation and the xanthophyll cycle in the leaves effectively protected pho-tosynthetic PSⅡ and enhanced light energy utilization of leaves under NaCl stress. The increased nitrogen promoted photosynthetic electron supply and transport ability under NaCl stress evident in enhanced functioning of the oxygen-evolving complex on the electron donor side of PS Ⅱ. It increased the ability of the receptor pool to accept electrons on the PSII electron acceptor side and improved the sta-bility of thylakoid membranes under NaCl stress. Therefore, increasing nitrogen applications under NaCl stress can promote poplar growth by improving the effi-ciency of light energy utilization.The solution culture method was used to study the effect of increasing nitrogen on the growth and photosynthesis of poplar seedlings under 100 mmol L-1 NaCl stress.I Increase in nitrogen reduced stomatal limitation of leaves under NaCl stress,improved utilization of CO2 by mesophyll cells,enhanced photosynthetic carbon assimilation capacity,significantly alleviated saline damage of NaCl,and promoted the accumulation of aboveground and root biomass.I Increased nitrogen enhanced photochemical efficiency（APSII） and electron transport rates,relieved the reduction of maximum photochemical efficiency（Fv/Fm）under NaCl,and reduced the degree of photoinhibition caused by NaCl stress.Increased nitrogen applications reduced the proportion of energy dissipating in the form of ineffective heat energy and hence a greater proportion of light energy absorbed by leaves was allocated to photochemical reactions.Under treatment with increased nitrogen,the synergistic effect of heat dissipation and the xanthophyll cycle in the leaves effectively protected photosynthetic PSII and enhanced light energy utilization of leaves under NaCl stress.The increased nitrogen promoted photosynthetic electron supply and transport ability under NaCl stress evident in enhanced functioning of the oxygenevolving complex on the electron donor side of PSII.It increased the ability of the receptor pool to accept electrons on the PSII electron acceptor side and improved the stability of thylakoid membranes under NaCl stress.Therefore,increasing nitrogen applications under NaCl stress can promote poplar growth by improving the efficiency of light energy utilization.

关 键 词：POPLAR NITROGEN NACL stress PHOTOSYNTHETIC characteristics 

分 类 号：S[农业科学]