高AC水稻淀粉合成相关酶基因表达的温度效应

Effect of Temperatures on Gene Expression of Enzymes Associated with Starch Synthesis in a High AC Rice Cultivar

以高直链淀粉含量(AC)早籼稻品种嘉育353为材料,利用人工气候箱设置高温(日均温32℃)和适温(日均温22℃)2个温度处理,采用实时荧光定量PCR技术分析了不同灌浆温度下水稻胚乳中3个淀粉分支酶基因(sbe1、sbe3和sbe4)、3个淀粉脱支酶基因(R酶基因、isa1和isa2)以及2个淀粉合酶(GBSSⅠ和SSSⅠ)基因的表达特性。结果显示,除了sbe4、isa1和GBSSⅠ基因外,其余基因高温下表达量均显著高于适温,表明sbe1、sbe3、R酶基因、isa2以及SSSⅠ基因属于温度敏感型基因,可能在水稻胚乳淀粉合成的温度调控方面起着关键作用。

Plants of a high AC early-season indica rice cultivar‘Jiayu 353’at flowering stage were placed from the field and cultured at two temperature regimes（high daily mean temperature, 32 ℃ and low daily mean temperature, 22 ℃）in two phytotrons, and the real-time PCR was employed to study gene expression of enzymes associated with starch synthesis, including starch branching enzymes（SBE1, SBE3 and SBE4）, starch debranching enzymes（ISA1, ISA2 and R-enzyme） and starch synthases（GBSS I and SSS I） in the rice endosperm during grain filling under these two different temperatures. The results show that high temperature significantly increased gene expression of 5 enzymes（SBE1, SBE3, R-enzyme, ISA2 and SSS I）. These suggested that the genes of these enzymes were sensitive to the temperature variation and may be the key genes through which the temperature affected starch accumulation in rice endosperm during grain filling.