外源甜菜碱对干旱胁迫下小麦幼苗膜脂过氧化作用的影响

用PEG4000溶液对小麦（Triticum aestivum L.heimang)幼苗进行胁迫处理和加入外源甜菜碱（Betaine)作同样处理，6、12、18和24h测定生理变化。结果表明，与对照相比，外源甜菜碱导致小麦幼苗叶片含水量下降，相对膜透性增大，MDA含量升高，SOD和POD活性先降后增，同时脯氨酸大量积累。说明外源甜菜碱对小麦幼苗受伤害程度有明显加深作用。

The effect of external betaine on membrane lipid peroxidation of wheat seedling under water stress

Using solution of PEG4000 to deal with wheat ( Triticum aestivum L. heimang ) seedling as control,we add betaine to solution of PEG4000 to deal with wheat seedling for spans of 6 hours,12 hours,18 hours and 24 hours,and determine the physiological changes in leaves of wheat seedling.The results indicated that,making all possible comparisons with control,treating wheat seedling with solution of external betaine and PEG4000 decreased the water content of wheat seedling leaves,increased the membrane relative permeability of wheat seedling leaves;increased the content of MDA of wheat seedling leaves,decreased the activities of SOD and POD of wheat seeding leaves at first,then increased them;at the same time,led to large accumulation of proline of wheat seeding leaves.Conclusively,external betaine can enhances the degree of injury of wheat seedling.