为探究喷施γ-氨基丁酸（GABA）对不同程度盐分胁迫下水稻秧苗生长的影响，以天津主栽粳稻品种天隆优619为研究对象，在秧苗采用穴盘培育到3叶1心时，分别用0、25、50、75、100 mmol/L NaCl溶液水培，并设置叶面喷施4 mmol/L GABA处理，以叶面喷水作为对照组，调查水稻的生长指标和3种抗氧化酶活性。结果表明，随着盐分胁迫程度的增加，水稻的株高增量、叶面积呈下降趋势，死叶率、根系干鲜比、叶片POD和SOD酶活性呈上升趋势，根系活力和叶片APX酶活性呈先升后降趋势。在相同盐分胁迫下，与不喷施GABA对照相比，喷施GABA处理表现为：株高增量增加1.7%~32.4%，死叶率降低1.6%~23.3%，根干质量减少9.3%~22.0%，根系活力增加1.2%~94.4%，叶片POD、SOD和APX酶活性分别增加5.0%~20.8%、9.8%~17.3%和7.2~64.4%。可见，叶面喷施4 mmol/L GABA能够提高供试水稻的耐盐性，促进同化物优先向地上部分配。

Abstract：The aim of this study is to clarify the effects of spraying Gamma-aminobutyric acid (GABA) on growth of rice seedlings under different levels of salt stress. Tianlongyou 619, a major japonica rice variety in Tianjin was used as the research material. Rice seedlings were cultivated in plugs and transplanted into hydroponic cups when 3 leaves expanded. five NaCl solutions (0, 25, 50, 75, 100 mmol/L) were tested. 4 mmol/L GABA solution was sprayed to leaves as experimental group, and water was used as the control group. Seedling growth and physiological characteristics under salt stress were analyzed. The results showed that, with the increase of salt stress, the plant height increment and leaf area of rice showed a downward trend; dead leaf rate, root dry-fresh ratio, POD and SOD enzyme activities in leaves showed an upward trend; root activity and APX enzyme activity in leaves increased first and then decreased. Under the same salt stress, compared with the treatment without spraying GABA, the four salt stress treatment with spraying GABA showed: plant height increment increased by 1.7%~32.4%, dead leaf rate decreased by 1.6%~23.3%, root dry weight decreased by 9.3%~22.0%, root activity increased by 1.2%~94.4%, POD, SOD and APX enzyme activities increased by 5.0%~20.8%, 9.8%~17.3% and 7.2%~64.4%, respectively. It can be seen that foliar spraying of 4 mmol/L GABA on the leaf surface could improve the salt tolerance of rice and promote the assimilation to be preferentially allocated to the aboveground parts.