不同花生品种氮代谢相关酶活性的研究

为研究不同品种花生各器官中氮代谢酶活性的差异及与籽仁蛋白质含量间的关系,采用田间小区试验,利用高产大花生品种(花育22号)和小花生品种(白沙1016)研究了两品种不同生长发育时期植株各器官中可溶性蛋白质(Pro)含量、硝酸还原酶(NRase)、谷氨酰胺合成酶(GS)和谷氨酸脱氢酶(GDH)活性的变化。结果表明,两粒型花生品种各器官的Protein、NRase、GS、GDH活性变化态势大致相同,但其含量的高低有异;各器官中的各指标含量均以小花生品种白沙1016较高。各器官中NRase活性随生育期的推进呈渐降趋势,籽仁中NRase活性远高于其他营养器官;两粒型品种叶片、茎和根中GS活性的变化趋势均呈单峰曲线,其峰值均出现在结荚期;叶片GDH活性以苗期较高,花针期最低,之后又迅速升高。茎和根中GDH活性均呈V字型曲线变化,根中峰谷滞后于茎,出现在饱果期,而籽仁中GDH活性成熟期略有升高。各器官中蛋白质含量与GS和GDH活性间的相关关系不明显,但与其相应器官中的NRase活性表现显著或极显著相关。

Enzyme activities responsible for nitrogen metabolization in different peanut cultivars

Two peanut cultivars,Huayu 22(high yield big peanut) and Baisha 1016(small peanut),were used for investigating the changes of activities of nitrate reductase(NRase),glutamine synthetase(GS) and glutamate dehydrogenase(GDH),and soluble protein contents in different organs.The results showed that the change trends of NRase,GS,GDH and protein contents of two type peanut cultivars were similar.But the protein contents of different organs of Baisha 1016 were higher than those of Huayu 22.The NRase activities of different organs were gradually depressed with growth.The NRase activity of nutlet was higher compared to the other organs.The changes of GS activities in stem and root showed a single peak curve with the peak appeared at grouting stage.The GDH activities in leaves were relatively higher at seedling stage,then reached lowest at pod-pin stage,and increased rapidly afterward.The changes of GDH activities both in stem and root presented a "V" type curve.The peak GDH in root appeared later that in stem,which was observed at pod-maturing stage.GDH activities in nutlet at mature stage were higher than that of pod-maturing stage.No significant relationships were found between protein contents and the activities of GS and GDH in organs,while protein contents were significant correlated with the NRase activities in corresponding organs.