《植物生理学报》 2017, 53(12): 2125-2136

NaCl处理对西伯利亚白刺幼苗中矿质元素含量的影响

李焕勇, 唐晓倩, 杨秀艳, 武海雯, 张华新^*

国家林业局盐碱地研究中心, 林木遗传育种国家重点实验室, 北京100091

通信作者：张华新；E-mail: zhanghx1998@126.com

摘　要：

西伯利亚白刺(Nitraria sibirica)是我国荒漠及盐碱地的先锋树种, 为典型的稀盐型盐生灌木。为探讨盐胁迫对西伯利亚白刺不同组织矿质元素含量及分布的影响, 在水培条件下, 以一年生实生苗为材料, 分别研究了0、100、200、300和400 mmol·L^-1 NaCl处理1和14 d后不同组织中矿质元素含量、K/Na比及K、Ca选择性运输能力。结果表明: 西伯利亚白刺各组织中矿质元素含量对不同时间及不同浓度NaCl处理的响应存在着差异, 且Na为第一主成分主要差异因素。随着NaCl处理浓度的升高及处理时间的延长, 各组织中Na含量显著增加, 400 mmol·L^-1 NaCl处理14 d后叶部Na含量高达20.37 mg·g^-1 (DW)。K含量在各处理中变化相对平稳, 随着NaCl处理浓度的升高, 叶中K含量受影响最大。高浓度NaCl处理同样影响Ca、Mg、Fe、Cu元素的吸收与运输, 但在低浓度或中浓度NaCl处理下, K、Ca、Fe、Mn元素含量增加。西伯利亚白刺各组织中K/Na与Ca/Na比值随NaCl处理浓度的升高而降低, K/Na与Ca/Na比值在不同组织大小顺序为根>茎>叶。证明西伯利亚白刺具有较强的耐盐性可能是由于其作为稀盐盐生植物将Na运输到叶片并转运到液泡中以降低细胞中Na的毒害及维持渗透平衡, 并调节K、Ca、Fe、Mn元素的吸收、运输与分配, 确保各种新陈代谢顺利进行。

关键词：西伯利亚白刺; NaCl处理; 矿质元素

收稿：2017-07-12   修定：2017-11-10

资助：“十二五”国家科技支撑计划(2015BAD07B0102)和国家重点研发计划(2016YFC0501303)。

Effects of NaCl stress on mineral element contents in Nitraria sibirica seedlings

LI Huan-Yong, TANG Xiao-Qian, YANG Xiu-Yan, WU Hai-Wen, ZHANG Hua-Xin^*

Research Center of Saline and Alkali Land of State Forestry Administration, State Key Laboratory of Tree Genetics and Breeding, Beijing 100091, China

Corresponding author: ZHANG Hua-Xin; E-mail: zhanghx1998@126.com

Abstract:

We investigated the effects of salt stress on the content and distribution of mineral elements in different organs of Nitraria sibirica. One-year-old seedlings of N. sibirica were treated in solution cultures containing 0, 100, 200, 300, and 400 mmol·L^-1 of NaCl. Seedlings were sampled on the first and fourteenth days after treatment to evaluate the mineral element contents, K/Na ratios, and the selective transport ability of K and Ca in different organs. The mineral element contents in various tissues of N. sibirica varied in response to the NaCl concentrations; the main difference factor of principal component 1 (PC1) was related to Na content, which significantly increased in different tissues with increased NaCl concentrations and prolonged treatment times. N. sibirica seedlings treated for 14 days with 400 mmol·L^-1 NaCl had a Na content of 20.37 mg·g^-1 (DW) in leaves. The K content of various organs was relatively stable in each treatment, and the content in leaves was greatest under the highest NaCl concentration treatments. High concentrations of NaCl also affected the absorption and transport of Ca, Mg, Fe, and Cu. However, the contents of K, Ca, Fe, and Mn increased under low or moderate concentrations of NaCl. K/Na and Ca/Na ratios in different tissues of N. sibirica decreased with increased NaCl concentrations. The order of K/Na and Ca/Na ratios in different tissues was roots > stems > leaves. Our results suggest that the high salt tolerance of N. sibirica may be due to the transport of Na to leaves, whereby it is transferred into vacuoles to avert the deleterious effects of Na, maintain osmotic equilibrium in the cytosol, and regulate the absorption, transport, and distribution of K, Ca, Fe, Mn, etc. to maintain normal metabolic functions.

Key words: Nitraria sibirica; NaCl stress; mineral element