摘要
为研究小麦籽粒淀粉合成酶基因表达与酶活性的特征，以普通小麦品种秦麦11（粒重36．942rag／粒，淀粉含量61．02％）和中优9507（粒重50．636mg／粒，淀粉含量68．36％）为材料，采用实时荧光定量RT-PCR方法，对灌浆期籽粒淀粉合成酶相关基因的表达进行了研究，并对其表达量与相应酶活性的相关性做了分析。结果表明，腺苷二磷酸葡萄糖焦磷酸化酶基因（AGPase）、束缚态淀粉合成酶基因（GBSSI）、可溶性淀粉合成酶基因（SSS）、淀粉分支酶基因（SBE）表达均呈单峰曲线变化，在花后3d内检测不到其表达，花后4～6d这些基因开始表达。AGPase和SSS在花后12d左右表达量达到高峰，GBSSI和SBE在花后15d左右的表达量最大。自花后18d开始，各基因的表达量均显著下降。中优9507在表达高峰期（即花后第12、15、18d）的酶基因相对表达量均显著高于秦麦11，且差异均达显著水平。整个灌浆期间中优9507的四种淀粉合成酶活性高于秦麦11，尤其在灌浆中期差异更显著。相关分析表明，AGPase、SSS、SBE基因在花后15d的相对表达量与相应酶活性间呈极显著正相关，而GBSS基因的相对表达量与GBSS酶活性间相关不显著，暗示AGPase、SSS、SBE基因在籽粒淀粉合成过程中属于转录水平调控，而GBSSI基因属于转录后调控。
Two wheat （ Triticum aestivum L.） cultivars, Qinmai 11 （low starch contents in grains） and Zhongyou 9507 （ high starch contents in grains） were used to investigate the expression levels of genes involving in starch biosynthesis, the activity changes of enzymes involved in starch biosynthesis, and the relations between them during wheat grain filling. The expression levels of genes were detected by real-time fluorescence quantitative PCR. The results indicated that the expression levels of adenosine diphosphorate glucose pyrophrylase gene （AGPase）, granule-bound starch synthase gene （GBSSI）, soluble starch synthase gene （SSS）, starch branching enzyme gene （SBE） demonstrated a single-peak curve during grain filling. The expressions of AGPase, GBSSI,SSS and SBE, were not detected at DAA（days after anthesis）3, but at DAA 4 6. The expression levels of AGPase and SSS reached the maximum at DAA 12, and declined significantly after DAA 18. The expression levels of GBSSI and SBE reached a maximum＇at DAA 15, and also declined significantly after DAA 18. The relative expression levels of AGPase, GBSS, SSS and SBE in Zhongyou 9507 were higher than those in Qinmai 11 at DAA 12, 15, 18, and the differences between them were significant. The activities of AGPase, GBSS, SSS and SBE in Zhongyou 9507 were also higher than those in Qinmai 11. In addition to GBSSI, the relative expression levels of AGPase, SSS and SBE were highly significantly correlated with the activities of AGPase, SSS and SBE at DAA 15. These suggested that AGPase, SSS, SBE may control starch synthesis at the transcriptional level, and GBSSI may control starch synthesis at the post-transcriptional level.
出处
《麦类作物学报》
CAS
CSCD
北大核心
2009年第1期24-30,共7页
Journal of Triticeae Crops
基金
江苏省"六大人才高峰"项目(07-G-008)
江苏省高校自然科学重大基础研究项目(07KJA21022)
江苏省农业支撑计划项目(BE200830737)
扬州大学自然科学基金项目(2007cxj015)
关键词
小麦
淀粉合成酶基因
荧光定量RT
PCR
基因表达
Wheat
Starch synthase gene
Real-time fluorescence quantitative PCR
Gene expression
