摘要
以超级杂交稻"两优培九"为试验材料,"汕优63"和"9311"为对照,研究了水稻开花后剑叶叶片中有关氮代谢相关酶类[硝酸还原酶(NR)、谷氨酰氨合成酶(GS)、谷-丙转氨酶(GPT)、谷-草转氨酶(GOT)、谷氨酰氨脱氢酶(GDH)、蛋白水解酶(proteinase)]活性及部分酶动力学变化,同期测定了可溶性蛋白和游离氨基酸含量变化及穗部农艺性状,旨在了解超级杂交稻品种与其常规亲本及对照品种在生育后期与氮代谢相关酶活性及动力学变化的内在规律性,为杂交稻生育后期的氮代谢调控提供科学依据。结果表明,花后1周为3个品种剑叶叶片中有关氮代谢酶活性的高值持续期,接着进入速降期。不同品种间NR、GS、GPT和GDH活性及活性高值期具有显著性差异。花后1周"两优培九"具有较高的GS和GDH活性;花后7~14 d"汕优63"的NR和GS活性显著高于"9311"和"两优培九",灌浆后期其GS、GDH活性和活性高峰,也均高于和迟于其他2个品种;"9311"在开花和灌浆初期具有较高的转氨酶活性和催化活性,其氮代谢的启动早于其他2个品种。生育后期GDH和GOT的活性变化说明氧化脱氨可能是水稻体内的主要脱氨方式。生育后期NR和GS活性与其催化活性呈非线性关系,GPT在花后14 d催化活力表现最低,在灌浆后期3种酶仍具有较高的催化活力。叶片可溶性蛋白及ATPase变化说明,酶蛋白量是制约水稻生育后期有关氮代谢的酶活性和影响后期氮素代谢的重要因素之一,叶片的能量状态是影响生理活性发挥的重要限制因子。从主要酶活性变化、籽粒灌浆速率和穗部性状看,生育后期种间杂交种("汕优63")比亚种间杂交种("两优培九")具有较高的叶生理活性和较强的籽粒灌浆优势。
The super hybrid rice "Liangyoupeijiu" was used as the test material in comparison with "Shanyou 63" and "9311".The comparison studied the changes in the activities of key enzymes involved in nitrogen metabolism,included NR(nitrate reductase),GS(glutamine synthetase),GPT(glutamic-pyruvie transaminase),GOT(glutamic-oxalacetic transaminase),GDH(glutamate dehydrogenase) and protease,in rice flag-leaves at the late developmental stage.The kinetics of NR,GS and GPT,contents of soluble proteins and free amino acids,and panicle traits were also investigated at the same time.The study was to build better understanding into the changes in the activities and dynamics of enzymes related with nitrogen metabolism in super hybrid rice,its parents and control variety at the late developmental stage.The study further explored the inherent mechanisms of these changes and provided scientific basis for regulating nitrogen metabolism in hybrid rice at the late developmental stage.The results showed that one week after blooming was the high-value duration of the activities of enzymes related with nitrogen metabolism in flag-leaves of the three rice varieties.After one week,the enzymes activities entered into the sharp-fall phase.The NR,GS,GPT and GDH activities and speaks activities among the varieties were significantly different.One week after blooming,higher activities of GS and GDH in "Liangyoupeijiu" rice variety were noted.Then 7~14 days after blooming,NR and GS activities in "Shanyou 63" rice were significantly higher than those of "9311" and "Liangyoupeijiu".Also GS and GDH activities and peak activities in "Shanyou 63" were higher and occurred at much later dates than those in the other two varieties at late grain-filling stage.At flowering and initial grain-filling stages,"9311" had higher trans-aminase and catalytic activities with nitrogen metabolism starting earlier than in the other varieties.The changes in GDH and GOT activities at late developmental stage suggested that oxidative deamination was the main vivo process.The relation between activities and catalytic activity of NR and GS were nonlinear at late developmental stage.Catalytic activity of GPT was lowest at 14 days after anthesis.As three kinds of enzymes at the late grain-filling stage still had higher catalytic activity combined with changes in soluble proteins and ATPase activity in flag-leaves,it was proposed that the contents of protein enzymes were the main factors affecting enzyme activity and nitrogen metabolism at the late developmental stage.The energy state of flag-leaves was an important limiting factor to the availability of physiological activity.The inter-specific hybrid rice("Shanyou 63") had the advantage of high physiological activity in the leaf and grain-filling stages than the sub-specific hybrid rice("Liangyoupeijiu").This was the main sources of changes in key enzyme activities,grain-filling rates and panicle traits.
出处
《中国生态农业学报》
CAS
CSCD
北大核心
2012年第12期1606-1613,共8页
Chinese Journal of Eco-Agriculture
基金
福建省教育厅科技项目(JA05238)
福建省生态学重点学科项目(0608537)资助
关键词
水稻
生育后期
氮代谢
酶活性
动力学
Rice
Late developmental stage
Nitrogen metabolism
Enzyme activity
Dynamics