氮素形态对菠菜体内抗坏血酸含量及其代谢的影响  

Effects of nitrogen forms on ascorbate contents and metabolism in spinach(Spinacia oleracea L.)

作　　者：孙园园[1] 林咸永[1] 金崇伟[1] 章永松[1] 方萍[1] 

机构地区：[1]浙江大学环境与资源学院教育部环境修复与生态健康重点实验室,浙江杭州310029

出　　处：《浙江大学学报（农业与生命科学版）》2009年第3期292-298,共7页Journal of Zhejiang University:Agriculture and Life Sciences

基　　金：国家重点基础研究发展计划"973"资助项目(2007CB109305);国家自然科学基金资助项目(30370840);教育部创新团队资助项目;浙江省"三农五方"科技协作计划资助项目;国际植物营养研究所(IPNI)资助项目

摘　　要：采用基质培养试验,研究营养液不同铵硝配比(0:100,25:75,50:50,75:25,100:0)对菠菜叶片抗坏血酸含量及其代谢相关酶活性的影响.结果表明,菠菜植株鲜重和干重以铵硝比为25:75处理最高,铵硝比超过50:50时则显著下降.菠菜叶片抗坏血酸(AsA)、总抗坏血酸(AsA+DHA)含量随着铵硝比的提高逐渐增加.菠菜叶片L-半乳糖酸-1,4-内酯脱氢酶(GalLDH)活性在铵硝比小于50%时没有显著变化,进一步提高铵硝比则显著降低;铵硝比不影响抗坏血酸氧化酶(AAO)的活性.脱氢抗坏血酸还原酶(DHAR)和单脱氢抗坏血酸还原酶(MDHAR)的活性均随着供铵比例提高而逐渐提高,且与AsA含量的变化趋势相似.表明提高营养液中铵硝比增加菠菜叶片AsA含量,与其提高MDHAR、DHAR活性和加快AsA的再生循环有关,而与其对GalLDH和AAO酶活性的影响没有明显的相关.The effects of ammonium-nitrogen （NH4 ＋-N） to nitrate nitrogen （NO3--N） ratios （0： 100, 25： 75, 50： 50, 75： 25, 100： 0） in the nutrient solution on ascorbate （AsA） contents and its related metabolic enzyme activities in hydroponically grown spinach（Spinacia oleracea L. ）were studied. Results show that both fresh and dry weights were significantly decreased when NH4＋-N to NO3--N ratio exceeded 50： 50, and highest fresh and dry weight was recorded at the NH4 ＋-N to NO3--N ratio of 25： 75. AsA and （AsA＋DHA） contents increased gradually, while the ratios of AsA/（AsA＋ DHA） had no significant change with increasing of NH4＋-N to NO3--N ratio. The enzymes activities of Lgalactono-1,4-1actone dehydrogenase （GalLDH） were not decreased until the ratio of NH4 ＋ -N to NO3- N was over 50：50 and the ascorbate oxidase （AAO） had no significant change with increasing NH4 ＋-N ratio. The ascorbate peroxidase （APX） activity was decreased firstly and then increased when the NH4＋-N ratio was elevated. The activities of two enzymes related to AsA regeneration, the dehydroascorbate reductase （DHAR） and monodehydroascorbate reductase （MDHAR） increased as well as the trends of ascorbate content when elevated NH4 ＋-N： NO3 --N ratio. The results suggested that AsA contents increased with increasing NH4＋-N to NO3--N ratio in the nutrient solution could be attributed to the enhanced DHAR and MDHAR activities in AsA metabolism, could not be significantly related to the changes of GalLDH and AAO activities.

关 键 词：氮形态 抗坏血酸 菠菜 L-半乳糖酸-1  4-内酯脱氢酶 脱氢抗坏血酸还原酶 单脱氢抗坏血酸还原酶 抗坏血酸过氧化物酶 

分 类 号：S636.1[农业科学—蔬菜学]