植物学报 ›› 2001, Vol. 18 ›› Issue (05): 587-596.

• 研究论文 • 上一篇    下一篇

盐胁迫条件下杨树盐分与甜菜碱及糖类物质变化

陈少良 李金克 毕望富 王沙生   

  1. (北京林业大学生物学院森林生物实验中心 北京 100083)
  • 收稿日期:2000-11-07 修回日期:2000-12-04 出版日期:2001-09-20 发布日期:2001-09-20
  • 通讯作者: 陈少良

Genotypic Variation in Accumulation of Salt Ions, Betaine and Sugars in Poplar Under Conditions of Salt Stress

CHEN Shao-Liang LI Jin-Ke BI Wang-Fu WANG Sha-Sheng   

  1. (Experimental Centre of Forest Biology, Beijing Forestry University, Beijing 100083)
  • Received:2000-11-07 Revised:2000-12-04 Online:2001-09-20 Published:2001-09-20
  • Contact: CHEN Shao-Liang

摘要: 以抗旱耐盐性强的胡杨(Populus euphratica)和非抗盐的群众杨(P. popularis‘35-44’)为实验材料,研究了盐胁迫条件下盐分与甜菜碱、还原糖、蔗糖以及水溶性糖等细胞相容溶质的动态变化。两种杨树在盐处理期间表现出明显差异:群众杨下部叶片首先表现出盐害症状,处理后两周苗木上部叶片也出现盐害并脱落。而胡杨在试验期间仅下部叶片发黄脱落,盐处理15天后落叶量仅为16%。群众杨盐害症状的出现主要是由叶片中盐离子的大量累积所致。与之比较,胡杨拒吸Na+的能力及控制Cl-转运的能力均优于群众杨。另外,胡杨的耐盐性强于群众杨也与其有机溶质的变化有关。受到盐胁迫后胡杨根叶中甜 菜碱浓度显著提高,在处理后15天达到最高值,特别是叶片中甜菜碱的浓度提高了243倍,达到1*!899.8 μmol/L,根中甜菜碱含量也增加了9倍。此外,盐处理后胡杨叶和根中的还原糖、水溶性糖和蔗糖含量均呈明显上升趋势,分别在第4天和第15天达到峰值。与胡杨相反,耐盐性弱的群众杨在盐胁迫期间,叶中甜菜碱和糖含量并无显著提高,根中糖分水平还明显降低。由此可以得出结论,胡杨渗透调节能力高于群众杨,是其耐盐性强的重要生理基础之一。

Abstract: Effects of NaCl on concentrations of salt ions, glycinebetaine, reducing sugars, sucrose and soluble sugars in one-year-old seedlings of a salt-tolerant poplar genotype, Populus euphratica and one_year_old rooted cuttings of a salt-sensitive genotype, P. popularis ‘35-44’were examined. Leaf burn symptoms appeared in old leaves of P. popularis after 4 days of exposure to salinity, and young leaves in the upper shoots exhibited leaf damage and abscised by day 15. In contrast, P. euphratica had only 16% leaf loss by day 15. Leaf necrosis of P. popularis was the result of excessive salt accumulation, and P. euphratica exhibited a greater ability to exclude Na+ and to limit Cl-transport from roots to leaves under increasing salinity. In addition, genotypic variation of salt resistance was related to the accumulation of compatible solutes. Leaf betaine content of P. euphratica increased 244_fold on day 15, up to 1899.8 μmol/L, and a 10-fold rise was also observed in roots. Similarly, levels of reducing sugars, sucrose and total soluble sugars significantly rised and reached the maximum on day 4 (leaf) and day 15 (root), respectively. By contrast, betaine levels of P. popularis declined following salt stress and no significant rise of sugars was observed in leaves and roots during the period of salt stress. Therefore, we concluded that the accumulation of compatible solutes made contributions to salt resistance of P. euphratica.