脱落酸对水稻愈伤组织糖类代谢及相关酶活性的影响

Effect of Abscisic Acid on Saccharide Metabolism and Related Enzyme Activities in Rice Callus

以水稻愈伤组织为材料，研究了外源脱落酸（ABA）对糖类代谢及相关酶活性的影响。ABA处理可促进淀粉和非还原糖在愈伤组织中的积累，以10～12mg／LABA作用效果最为显著。愈伤组织在处理培养期间，淀粉和非还原糖含量的动态变化受ABA影响明显。ABA能降低还原糖水平以及果糖与葡萄糖的比例，抑制磷酸葡萄糖同分异构酶（PGI）和转化酶的活性，增加磷酸葡萄糖变构酶（PGM）和淀粉磷酸化酶活性。试验结果表明，ABA对糖类代谢和相关酶活性的影响效果在处理的1～7d最为明显。推测非还原糖含量的升高可能是ABA促进其积累和抑制转化酶活性所致，淀粉含量升高的原因可能是ABA增强了淀粉磷酸化酶的活性，果糖与葡萄糖比值的降低可能是由于ABA对PGI活性抑制和对PGM活性促进的双重影响。

By using the calli of rice （Oryza sativa L. ） as materials, the effects of abscisic acid （ABA） on saccharide metabolism and related enzyme activities were studied. ABA treatments promoted the accumulation of starch and non-reducing sugar in the calli, especially under 10-12 mg/L ABA treatments. During the period of rice culture, the contents of starch and non-reducing sugar were also significantly affected by ABA. ABA remarkably decreased the activity of reducing sugar and the ratio of fructose to glucose. Meanwhile, ABA inhibited the activities of phospho-glucose isomerase （PGI） and invertase, increased the activities of phospho-glucose mutase （PGM） and starch phosphorylase, indicating that ABA was the most effective factor in saccharide metabolism and to the related enzyme activities on the 1st to 7th days after treatments. It was presumed that the increased content of non-reducing sugar might be resulted from the enhanced accumulation of non-reducing sugar as well as the inhibited invertase activity by ABA, and the increased starch content might come from the higher activity level of starch phosphorylase, and the decreased ratio of fructose to glucose might be due to the diplex effects of ABA on suppressing PGI and promoting PGM activities.