植物生态学报 ›› 2016, Vol. 40 ›› Issue (1): 69-79.DOI: 10.17521/cjpe.2015.0240

• 研究论文 • 上一篇    下一篇

亚麻响应盐、碱胁迫的生理特征

郭瑞1,2,*, 李峰1, 周际3, 李昊儒1,2, 夏旭1,2, 刘琪1,2   

  1. 1中国农业科学院农业环境与可持续发展研究所, 北京 100081
    2农业部旱作节水农业重点实验室, 北京 100081
    3国土资源部土地整治中心, 北京 100034
  • 出版日期:2016-01-31 发布日期:2016-01-28
  • 通讯作者: 郭瑞
  • 作者简介:

    # 共同第一作者

  • 基金资助:

    国家自然科学基金青年基金(31200243)、国家自然科学基金面上项目(31570328)、国家高技术研究发展计划(“863”计划) (2011AA100503)和中央公益性科研业务费(BSRF 201201)。

Eco-physiological responses of linseed (Linum usitatissimum) to salt and alkali stresses

GUO Rui1,2,*, LI Feng1, ZHOU Ji3, LI Hao-Ru1,2, XIA Xu1,2, LIU Qi1,2   

  1. 1Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, China
    2Key Laboratory of Dryland Agriculture, Ministry of Agriculture, Beijing 100081, China
    and 3Land Consolidation and Rehabilitation Centre, Ministry of Land and Resources of the People’s Republic of China, Beijing 100034, China
  • Online:2016-01-31 Published:2016-01-28
  • Contact: Rui GUO
  • About author:

    # Co-first authors

摘要:

利用中性盐NaCl、Na2SO4和碱性盐NaHCO3、Na2CO3混合模拟不同强度的盐、碱胁迫条件, 对亚麻(Linum usitatissimum)进行14天胁迫处理, 测定其地上部分和根生长速率、光合特征、离子平衡及有机渗透调节物质积累, 以探讨亚麻对盐、碱两种胁迫的生理响应特点。研究表明: 亚麻生长对盐、碱胁迫的响应存在差异, 在相同盐浓度下, 碱胁迫对亚麻的伤害大于盐胁迫。碱胁迫使地上部分中Na+浓度急剧增高, 造成叶绿体破坏、光合色素含量下降, 光合能力及碳同化能力也急剧下降。亚麻中Na+含量随着胁迫强度的增加而升高, 而K+含量呈下降趋势, 碱胁迫下的变化明显大于盐胁迫。因此, 碱胁迫导致Na+过度积累可能是碱胁迫对植物伤害大于盐胁迫的最主要原因。碱胁迫下Ca2+和Mg2+在根中下降明显, 可见高pH值阻碍根对Ca2+和Mg2+的吸收。Fe2+和Zn2+对渗透调节的影响不大, 因为它们的离子含量较低。盐胁迫促进阴离子(Cl-、H2PO4-和SO42-)的积累来平衡大量涌入的Na+, 但是碱胁迫明显减少无机阴离子含量, 可能造成严重营养胁迫(如P和S不足)。亚麻在盐胁迫下积累大量可溶性糖来平衡大量的Na+, 但碱胁迫下积累大量有机酸来维持细胞内离子平衡和pH值稳定, 碱胁迫大量积累的有机酸也可能被分泌到根外调节根外的pH值, 这说明亚麻对两种不同胁迫的响应方式不同。研究证明高pH值会直接影响植物根系的生长发育, 影响植物矿质元素的吸收, 阻碍离子稳态重建, 有机酸代谢是亚麻碱胁迫下的关键适应机制。

关键词: 亚麻, 盐胁迫, 碱胁迫, 生长特性, 光合特性, 离子平衡, 渗透调节

Abstract: AimsEffects of salt and alkali stresses (NaCl-Na2SO4 and NaHCO3-Na2CO3) were compared on growth, photosynthesis characters, ionic balance and osmotic adjustment of linseed (Linum usitatissimum), to elucidate the mechanisms of salt and alkali stress (high pH value) damage to plants, and their physiological adaptive mechanisms to the stresses. MethodsThe experiment was carried out in an artificial greenhouse. Plants grew at approximately 700 mmol·m-2·s-1 photosynthetic photon flux density (PPFD) in greenhouse under photoperiod of 15 h in light and 9 h in dark. In each plastic pot (17 cm diameter) which contained 2.5 kg of washed sand, 20 linseed seeds were sown. The seedlings were exposed to stresses lasting 14 days after 2 months.Important findingsThe inhibitory effects of alkali stress on linseed growth were more remarkable than those of salt stress, indicating that alkali and salt represent two distinct forms of stress. The alkali stress increased the Na+ content in shoots, damaged the photosynthetic system, and highly reduced the net photosynthetic rate and C assimilation capacity. Under salinity stress, the Na+ content increased, the K+ content decreased with increasing stress. Greater changes were observed under alkali than under salt stress. Alkali stress caused the massive influx of Na+, which probably explained that the harmful of alkali stress on plants was stronger than that of salt stress. Under alkali stress, Ca2+ and Mg2+ decreased in roots, showing that high pH value around roots hindered the absorption of them. Fe2+ and Zn2+ had little effects on the osmotic adjustment, mainly because of they had a low ion content. Under salt stress, anion increased in order to balance the sharp increase of Na+. However, alkali stress made severe deficit of negative charge, broke the intracellular ionic balance and pH homeostasis, and caused a series of strain response. Our results showed that linseed enhanced the synthesis of soluble sugars to balance massive influx of Na+ under salt stress, but linseed enhanced the synthesis of organic acids to compensate for the shortage of inorganic anions, which might be a key pathway for the pH adjustment. In conclusion, the alkali stress (high pH value) clearly inhibited the growth, element absorption, ion homeostasis reconstruction of plants. Organic acid concentration is possibly a key adaptive factor for linseed to maintain intracellular ion balance and regulate high pH value under alkali stress.

Key words: Linum usitatissimum, salt stress, alkali stress, growth characters, photosynthesis characters, ionic balance, osmotic adjustment