短期NaCl胁迫对西伯利亚白刺幼苗Na^+、K^+分配和平衡的影响  

Effects of Short-time Salt Stress on Distribution and Balance of Na^+ and K^+ in Nitraria sibirica Pall. Seedlings

作　　者：唐晓倩[1] 李焕勇[1] 杨秀艳[1] 刘正祥[1] 张华新[1] 

机构地区：[1]国家林业局盐碱地研究中心,北京100091

出　　处：《林业科学研究》2017年第6期1022-1027,共6页Forest Research

基　　金："十二.五"国家科技支撑计划课题(2015BAD07B0102)

摘　　要：[目的]为探究西伯利亚白刺盐适应机制。[方法]以1年生西伯利亚白刺水培幼苗为材料,研究不同浓度NaCl(0、200、300 mmol·L-1)胁迫24 h后根系Na^+、K^+离子流的动态变化(利用扫描离子选择微电极技术,SIET)及植株各器官中Na^+、K^+含量的静态变化(利用电感耦合等离子体光谱仪,ICP-OES)。[结果]表明:(1)短期NaCl胁迫显著提高了西伯利亚白刺根、茎、叶中Na^+含量,其中,叶中Na^+含量是根中的3倍以上;西伯利亚白刺根、茎、叶中K^+含量保持稳定或上升;(2)盐胁迫下,西伯利亚白刺根、茎、叶中K^+/Na^+呈下降趋势,其中,在200、300 mmol·L-1NaCl胁迫下,根中K^+/Na^+差异不显著;(3)离子流结果显示,NaCl胁迫显著提高了西伯利亚白刺根系Na^+的外流;对照和200 mmol·L-1NaCl胁迫下,K^+净流量分别为156、159 pmol·cm-2·s-1,差异不显著;300 mmol·L-1NaCl胁迫显著提高了K^+的内流,净流量为-370 pmol·cm-2·s-1。[结论]综合分析认为,西伯利亚白刺通过叶片对Na^+区隔,加强根系对Na^+的外排和K^+内流,进而维持植株根系K^+/Na^+的相对平衡,以此适应盐渍环境。[Objective] To explore the salt adaptation mechanism of Nitraria sibirica Pall. [Method] The net fluxes of Na^＋ and K^＋ from apex root （using scanning ion-selective electrode technique） and the contents of Na^＋ and K^＋ in different organs （using ICP-OES Spectrpmeter） were investigated in N. sibirica seedlings under the stress of different NaCl concentration （0, 200 and 300 mmol·L^-1） for 24 hours. [Result] （1） Short-term NaCl stress significantly increased Na^＋ content in roots, stems, and leaves of N. sibirica seedlings, and the Na^＋ content in leaves was three times that in roots; the content of K^＋ in roots, stems, and leaves of N. sibirica seedlings remained stable or increased. （2） The K^＋/Na^＋ ration in roots, stems, and leaves of N. sibirica seedlings decreased under salt stress. The K^＋/Na^＋ ration in roots showed no significant difference under 200 or 300 mmol·L^-1 NaCl stress. （3） The results of ion fiux showed that NaCl stress significantly increased the Na^＋ efflux in roots. The net K^＋ fluxes of control and 200 mmol·L^-1 NaCl stress were 156 pmol·cm^-2·s^-1and 159 pmol·cm^-2·s^-1respectively, and no significant difference was observed. 300 mmol·L^-1 NaCl stress significantly increased the influx of K^＋, the net K^＋ flux was -370 pmol·cm^-2·s^-1 [Conclusion] In conclusion, N. sibirica can efficiently sequestrate Na^＋ into leaves, as well as strengthen the roots Na^＋ efflux and K^＋ influx ability, and thus maintains the relative balance of K^＋/Na^＋ in plant root, so as to adapt to the salty environment.

关 键 词：西伯利亚白刺 NACL胁迫 离子流 K^+/Na^+平衡 

分 类 号：S722.3[农业科学—林木遗传育种]