盐胁迫下玉米幼苗ABA和GABA的积累及其相互关系

ACCUMULATIONS AND CORRELATIONS OF ABA AND GABA IN MAIZE SEEDLING UNDER SALT STRESS

盐胁迫下玉米幼苗内源脱落酸(abscisicacid,ABA)和γ-氨基丁酸(gamma-aminobutyricacid,GABA)含量增加,且ABA的积累先于GABA.用100μmol/L外源ABA和150mmol/LNacl处理使玉米幼苗内源GABA含量增加,NaCl和ABA同时处理时,对玉米幼苗GABA积累的诱导表现加合效应.ABA生物合成抑制剂氟草酮预处理后使盐胁迫诱导的GABA含量增加幅度减小,说明在盐胁迫下ABA调节GBAA积累.NaCl和ABA处理均刺激谷氨酸脱羧酶(GAD)的活性,推测盐胁迫下ABA通过调控GAD的活性而导致GABA积累.

The effects of abscisic acid （ABA） and NaCl on gamma-aminobutyric acid （GABA） content in maize seedling were investigated. The results showed that GABA content varied greatly responding to different ABA and NaCl treatments, The additive effect of the treatment with the solution containing 100μmol/L ABA and 150 mmol/L NaCl on GABA content was bigger than that of the treatment with lO0μmol/L ABA or 150 mmol/L NaCl, It was considered that there was a relationship between ABA and NaCl in promoting GABA accumulation. Both the contents of ABA and GABA were increased in maize seedling, but ABA was accumulated prior to GABA under the treatment with 150 mmol/L NaCl. While pretreated with 10μmol/L fluridone following 150 mmol/L NaCl, the change in GABA content was decreased greatly. It proves that ABA may regulate the accumulation of GABA under salt stress, and both NaCl and ABA stimulate the activity of glutamate decarboxylase （ GAD ）. It is inferred that salt stress and ABA result in the accumulation of GABA by increasing the GAD activity. Fig 6, Ref 18