铝胁迫下黑麦根尖分泌有机酸和钾离子的研究

采用药理学研究方法,研究了几种抑制剂和脱落酸对铝诱导黑麦根尖分泌有机酸和钾离子的影响。结果表明,在铝(100、200、300μmol/L AlCl3)胁迫下,根尖分泌柠檬酸、苹果酸和钾离子,且随着铝处理浓度的增加其分泌量显著增加。阴离子通道抑制剂苯甲酰甲醛(0.1、0.2 mmol/L)抑制根尖在铝(200μmol/L AlCl3)胁迫下分泌有机酸的同时,也抑制根尖分泌钾离子;钾离子通道抑制剂四乙基铵(20、40 mmol/L)和铯(10、20 mmol/L CsCl)在抑制根尖分泌钾离子的同时,也抑制铝诱导的有机酸分泌。25、50μmol/L的ABA处理后,铝诱导的有机酸分泌和钾离子的分泌均显著增加。但是,铝诱导的有机酸分泌在受到阴离子通道抑制剂尼氟灭酸(0.4、0.8 mmol/L)处理抑制后,钾离子的分泌并不减少;铝胁迫下根尖分泌的钾离子在ATP酶抑制剂钒酸钠(0.25、0.50、2.00 mmol/L)处理后受阻的同时,有机酸的分泌却显著增加。这些结果说明,钾离子是铝诱导黑麦根尖分泌有机酸的陪伴离子,而并非有机酸分泌的调控因子。

Secretion of organic acid anions and potassium from root apices under Al stress in Secale cereale L.

Aluminum (Al)-induced secretion of organic acid anions and potassium from root apices as the effects of several inhibitors and ABA in rye (Secale cereale L.) were investigated in the presented study using pharmacological methods. Under Al stress (100, 200 and 300 µmol/L AlCl₃ ), the secretions of citrate, malate and potassium increased with the incretion of Al concentration. This secretion was inhibited by the treatment with anion channel inhibitor phenylglyoxal ( 0.1, 0.2 mmol/L PG). Moreover, treatments with potassium channel inhibitors tetraethyl ammonium (20, 40 mmol/L) or Cs⁺ (10, 20 mmol/L CsCl) blocked remarkably the secretion of organic acid anions, which was coupled with the inhibition of potassium secretion. In addiction, the secretion of both organic acid anions and potassium was much more robust with the exposure of root apices to Al and ABA (25 or 50 µmol/L). Niflumic acid (0.4 or 0.8 mmol/L NA ), an anion channel inhibitor, suppressed remarkably the secretion of organic acids, while the secretion of potassium was not depressed. The potassium secreted under Al stress was depressed after the treatment with ATPase inhibitor, vanadate (0.25, 0.50 or 2.00 mmol/L), while the organic acids were increased significantly after the treatment. These results suggest that potassium involves in Al-induced secretion of organic acids in rye as an accompanied cation instead of a regulator factor.