水分胁迫对水稻叶片可溶性糖和游离脯氨酸含量的影响

在营养液培养条件下,测定了水稻品种金优402幼苗叶片中可溶性糖、游离脯氨酸和游离氨基酸的含量。结果表明,经50g/L PEG-6000处理5d的植株,其叶片可溶性糖、游离脯氨酸和游离氨基酸总量均增加。PEG处理1d,可溶性糖和游离氨基酸总量上升到最大值,并分别达到对照的1.6倍和1.98倍;PEG处理3d,游离脯氨酸上升到最大值,达到对照的1.6倍,游离脯氨酸维持较高值的时间比可溶性糖多2d。可溶性糖、游离脯氨酸和游离氨基酸总量的累积在水分胁迫前期均表现为急剧上升的趋势,达到峰值后开始下降,下降的趋势为先剧烈后缓慢,最后在胁迫解除2d后减少到接近对照的水平。试验期间,水稻叶片中游离脯氨酸占游离氨基酸总量的百分数在处理与对照间无明显差异,两者均在4%左右。

Effects of Water Stress on Soluble Sugars and Free Proline Content in Leaves of Rice

A solution cultivation experiment,with /without PEG,was conducted to evaluate the effects of water stress on soluble sugars and free proline content in leaf of rice variety Jinyou 402 cultivated in simulating water stress condition.The results were as follows:the content of soluble sugars,free proline and total free amino acid in leaf of rice under 5 days water stress induced by 50 g/L PEG all increased;the content of soluble sugars and total free amino acid of leaves treated with PEG for 1 day reached their maximum and arrived at 1.6 times and 1.98 times compared with the control;the free proline content in leaves treated with PEG for 3 days reached its maximum and was 1.6 times as much as that of control and the duration of keeping the peak value of free proline was 2 days longer than that of soluble sugars;the accumulation of soluble sugars,free proline and total free amino acid mounted up rapidly during prophase of water stress and arrived the peak values,then dropped rapidly at first and slowly declined to near the levels of the control after 2 days of water stress relief.The ratio of free proline content to total free amino acid content in the leaves was 4% or so,there was no significant difference between treatments and the control.