摘要
以早籼水稻嘉935和嘉353为材料,利用人工气候箱设高温(32℃)和适温(22℃)处理,探讨了高温对水稻籽粒氮代谢关键酶活性的影响及其与籽粒粗蛋白含量和各种氨基酸组成间的关系,并结合荧光定量PCR对水稻籽粒谷氨酰胺合成酶(GS)2个同工型基因的表达及其温度响应进行了检测分析。结果表明,花后高温处理对谷草转氨酶(GOT)和谷丙转氨酶(GPT)的影响基本一致,均表现灌浆前期升高、后期下降的趋势,但花后高温处理下水稻籽粒中粗蛋白总量和各类氨基酸含量的增加,并不一定是其籽粒氮素物质的转运能力和蛋白质合成能力的增强所致;谷氨酰胺合成酶(GS)在高温处理下的生理活性普遍高于其相应时期的低温处理,其中,GS2是GS基因在水稻胚乳中高表达的一种同工型,在水稻灌浆后期的表达量甚至超过GS1,高温胁迫处理会通过改变GS1和GS2基因在籽粒中的转录水平,从而对水稻籽粒灌浆中后期的GS活性产生调控。
The influence of high temperature after flowering period on the activities of some enzymes,including glutamine syn-thetase（GS）,glutamic-oxaloacetic transaminase（GOT） and glutamic-pyruvic transaminase（GPT） in developing grains,and also its relation to grain storage protein and amino acid accumulations were investigated by using two early-indica rice cultivars grown under two temperature regimes of daily average temperature 32℃ and 22℃,respectively,and expression responses of two GS isoform genes to temperature were detected by real-time fluorescence quantitative PCR（FQ-PCR）.The results indicated that the effects of high temperature after flowering period on GOT and GPT activities showed the similar trend,with increasing at early grain filling stage and decreasing at late grain filling stage.However,the increase of total contents of crude protein and various amino acids under high temperature after flowering period were not always due to the enhancement of grain nitrogen transport capacity and protein synthesis ability.GS activity under high temperature was generally higher than that under temperature in the same period.GS2,one of the isoforms of GS gene,was highly expressed in rice endosperm.The expression levels of GS2 was even higher than that of GS1 in late grain filling stage,while high temperature stress regulated GS activity through changing GS1 and GS2 genes transcription level in grain.
出处
《作物学报》
CAS
CSCD
北大核心
2012年第1期99-106,共8页
Acta Agronomica Sinica
基金
国家自然科学基金项目(30871488)
浙江省自然科学基金项目(Y307086)资助
关键词
水稻
高温
氮代谢
酶活性
蛋白积累
Rice（Oryza sativa L.）
High temperature
Nitrogen metabolism
Enzyme activity
Protein accumulation
