钙对低氧胁迫下黄瓜幼苗根系碳水化合物代谢的影响

以对低氧敏感的中农8号黄瓜品种为材料,研究了钙对低氧胁迫下幼苗根系淀粉、蔗糖、果糖、葡萄糖含量及蔗糖合酶(SS)、蔗糖转化酶(INV)、磷酸蔗糖合成酶(SPS)和葡萄糖激酶(GK)活性的影响。结果表明:与通气对照相比,低氧胁迫处理后幼苗根系淀粉含量降低,蔗糖和果糖含量增加,SS和GK活性增加,INV活性降低,胁迫初期SPS活性增加,后期降低;低氧胁迫下营养液加钙处理缓解了低氧胁迫对幼苗生长的抑制作用,根系SS、SPS、INV和GK活性增加,蔗糖和果糖含量显著高于单纯低氧胁迫处理,葡萄糖含量低于单纯低氧胁迫处理;而低氧胁迫下营养液缺钙处理加重了低氧胁迫对黄瓜幼苗的伤害。表明在低氧胁迫下,钙参与了调节黄瓜幼苗根系碳水化合物代谢,对提高幼苗低氧胁迫的适应性起着重要的作用。

Effects of Ca2+ on Carbohydrate Metabolism in Roots of Cucumber Seedlings under Hypoxia Stress

The effects of Ca2 on carbohydrate metabolism in roots of cucumber(Cucumis sativus L.var.Zhongnong 8) seedlings were studied under hypoxia stress in a nutrient solution culture system.The results showed that starch content,INV activity in roots of cucumber seedlings decreased,while the contents of sucrose and fructose,SS and GK activities increased significantly with hypoxia stress treatment compared with control.Under hypoxia treatment,SPS activity in roots increased significantly in the early period of treatment and then decreased in the later period.In hypoxia Ca2 treatment,seedling growth under hypoxia stress was not inhibited.SS,INV and GK activities,the contents of sucrose and fructose were higher in hypoxia Ca2 treatment than those of in the single hypoxia stress treatment,but contrary to glucose content.The results suggested that Ca2 could involved in the regulation of carbohydrate metabolism and play an important role in enhancing hypoxia tolerance in cucumber seedlings.