胺苯磺隆胁迫对水稻幼苗保护酶与内源激素的影响

Effects of Protective Enzymes and Endogenous Hormones of Seedling under Stress of Ethametsulfuron

[目的]通过研究低浓度的胺苯磺隆引起不同叶龄水稻叶片中保护酶和内源激素含量的变化,探讨超低浓度胺苯磺隆促生长效应的生理机制。[方法]通过土培法用2个浓度胺苯磺隆分别处理不同叶龄的水稻,15 d后采集水稻叶片,用愈创木酚-过氧化氢法测定过氧化物酶(POD)活性,用邻苯二酚法测定多酚氧化酶(PPO)的活性,用ELISA法测定水稻叶片中GA、ZR、ABA的含量。[结果]胺苯磺隆2μg/kg(干土)处理后水稻叶中PPO活性提高,POD活性降低但接近对照,GA、ZR含量显著增加,ABA含量则减少,GA/ABA的比值高于对照;胺苯磺隆20μg/kg处理,水稻叶中POD活性明显提高,PPO活性低于对照但接近对照,GA、ZR含量均显著减少,ABA含量则显著增加,GA/ABA的比值低于对照。7叶期处理的水稻叶片中3种激素含量与对照的差异最小。[结论]胺苯磺隆2μg/kg处理水稻,叶片内GA/ABA比值大于对照,对水稻生长有促进作用,20μg/kg浓度时,则GA/ABA比值明显小于对照,水稻生长受到抑制,同时,胺苯磺隆对7叶期水稻生长效应弱于4叶期前的水稻。

[Objective] The aim was to explore physiological mechanism of ethametsulfuron in growth promotion through research on variations of protective enzymes and endogenous hormones by ethametsulfuron of low concentration.[Method] Rice of different leaf ages were treated in ethametsulfuron of two concentrations through soil culture.Leaves of rice were collected after 15 d.POD,PPO,and contents of GA,ZR,and ABA were measured by guaiacol-hydrogen peroxide method,catechol method,and ELISA method,respectively.[Result] After treatment of ethametsulfuron with 2 μg/kg,activity of PPO was greatly enhanced,of POD was a little higher than the control;contents of GA and ZR were increased a lot and of ABA increased much;GA/ABA values were higher than that of control.In comparison,with treatment of ethametsulfuron at 20 μg/kg,activity of POD was greatly decreased,of PPO was a little lower then thecontrol;contents of GA,ZR decreased a lot and of ABA was greatly increased;ratio of GA and ABA was smaller than that of control.Among treated leaves during the period when the seventh leaf grown,three hormones contents were very close to that of control.[Conclusion] If rice was tested with ethametsulfuron of 2 μg/kg,value of GA/ABA in leaves was higher than the control one＇s,for which rice growth would be promoted.If the concentration was 20 μg/kg,ratio of GA and ABA was smaller than the control one＇s,for which,rice growth would be inhibited,and ethametsulfuron＇s effect on rice growth during the seventh leaf growing was weaker than that before the forth one growing.