Growth and cellular ion content of a salt-sensitive symbiotic system Azolla pinnata–Anabaena azollae under NaCl stress

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• 作者：V ; na Rai ; Naveen Kumar Sharma ; Ashwani K. Rai
• 关键词：Anabaena azollae ; Azolla pinnata ; Cellular ion content ; Growth ; Salinity
• 刊名：Journal of Plant Physiology
• 出版年：2006
• 出版时间：25 September 2006
• 年：2006
• 卷：163
• 期：9
• 页码：937-944
• 全文大小：214 K

文摘

Salinity, at a concentration of 10 mM NaCl affected the growth of Azolla pinnata–Anabaena azollae association and became lethal at 40 mM. Plants exposed up to 30 mM NaCl exhibited longer roots than the control, especially during the beginning of incubation. Average root number in plants exposed to 10 and 20 mM NaCl remained almost the same as in control. A further rise in NaCl concentration to 30 mM reduced the root number, and roots shed off at 40 mM NaCl. Presence of NaCl in the nutrient solution increased the cellular Na⁺ of the intact association exhibiting differential accumulation by individual partners, while it reduced the cellular Ca²⁺level. However, cellular K⁺ content did not show significant change. Cellular Na⁺ based on fresh weight of respective individual partners (host tissues and cyanobiont) remained higher in the host tissues than the cyanobiont, while reverse was true for K⁺ and Ca²⁺ contents. The contribution of A. azollae in the total cellular ion content of the association was a little because of meagre contribution of the cyanobiont mass (19–21 % ). High salt sensitivity of Azolla–Anabaena complex is due to an inability of the association to maintain low Na⁺ and high Ca²⁺ cellular level.