The experiment was designed, via storing potato tubers of cv. E-Potato1 and E-Potato3 indifferent temperatures, to explore the variation patterns of reducing sugar (RS) andtotal sugar (TS) contents and enzyme activiti...The experiment was designed, via storing potato tubers of cv. E-Potato1 and E-Potato3 indifferent temperatures, to explore the variation patterns of reducing sugar (RS) andtotal sugar (TS) contents and enzyme activities that are involved in the pathway ofstarch-sugar metabolism aiming at identifying the main factors that influence the chipcolor. The results showed that low temperature in storage was a main factor thataccelerated the accumulation of RS of the stored tubers and a very significant linearrelationship existed between RS content and chip color index (CCI) of the tubers. Furtheranalysis elucidated that when tubers stored at 4℃, the activities of ADP glucosepyrophosphorylase (AGPase), UDP glucose pyrophosphorylase (UGPase) and sucrose synthase(SuSy) were negatively exponential to the RS content significantly while that of acidinvertase and alkaline invertase was significantly linear to RS content. It suggestedthat these enzymes could play main roles in the cold sweetening of potato tubers throughregulating starch-sugar metabolism.展开更多
[Objective] This study aimed to analyze the effects of temperature on the expression of AGPase isoform genes in rice endosperm during milk stage. [Method] Different temperature treatments （33 and 25 ℃ of daily mean ...[Objective] This study aimed to analyze the effects of temperature on the expression of AGPase isoform genes in rice endosperm during milk stage. [Method] Different temperature treatments （33 and 25 ℃ of daily mean temperature for high and normal temperature treatments, respectively） and the real-time fluorescence quantitative PCR （ FQPCR） were used to analyze the expression patterns of seven isoforms （AGPS1, AGPS2a, AGPS2b, AGPL1, AGPL2, AGPL3 and AGPL4） of ADPglucose pyrophosphorylase （AGPase） which was the key enzyme in starch synthesis and metabolism in rice endosperm of two rice varieties Teqing and Thai Fragrant Rice. [Result] The AGPase isoforms AGPS2b, AGPL2 and AGPL3 had much higher expression than the other four isoforms, thus they were thought to be the main expression patterns of AGPase in rice endosperm. The relative expressions of AGPL2 was the highest among all the isoforms. The relative expressions of AGPS2b, AGPL2 and AGPL3 were higher in the normal temperature treatment than in the high temperature treatment in both rice varieties. The relative expression of the three enzyme genes in milk stages in Teqing was higher than those in Thai Fragrant Rice under different temperature treatments. [Conclusion] This study provides a theoretical basis for further use of molecular biology techniques to cultivate stable high-quality rice varieties.展开更多
木薯是重要的热带作物,具有高淀粉积累等特点,但其高效积累机制尚不明确。为研究腺苷二磷酸葡萄糖焦磷酸化酶(AGPase)大亚基对木薯淀粉积累的调控作用,本研究通过RT-PCR技术对木薯AGPase5个大亚基基因(MeAGPL1~MeAGPL5)进行筛选,发现MeA...木薯是重要的热带作物,具有高淀粉积累等特点,但其高效积累机制尚不明确。为研究腺苷二磷酸葡萄糖焦磷酸化酶(AGPase)大亚基对木薯淀粉积累的调控作用,本研究通过RT-PCR技术对木薯AGPase5个大亚基基因(MeAGPL1~MeAGPL5)进行筛选,发现MeAGPL3基因在木薯块根中高表达且受100μmol/L外源ABA正向调控;克隆了该基因2455 bp 5’侧翼序列,利用该序列及4个不同长度的5’端截短片段分别与β-葡萄糖醛酸酶(GUS)基因融合构建表达载体,转化本氏烟草,通过检测各转基因烟草GUS蛋白活性,发现-1至-1711 bp序列具有最佳的启动活性。利用100μmol/L外源ABA处理各转基因烟草株系,分析处理前后GUS蛋白活性变化,发现ABA信号响应元件分布于-1711至-2150区域。本研究为从转录调控角度阐释木薯淀粉高效积累机制提供理论支撑。展开更多
基金This research was supported by the National Natural Science Foundation of China(30270842)the Key Project of 10th Five-Year Plan of Hubei Province,China.
文摘The experiment was designed, via storing potato tubers of cv. E-Potato1 and E-Potato3 indifferent temperatures, to explore the variation patterns of reducing sugar (RS) andtotal sugar (TS) contents and enzyme activities that are involved in the pathway ofstarch-sugar metabolism aiming at identifying the main factors that influence the chipcolor. The results showed that low temperature in storage was a main factor thataccelerated the accumulation of RS of the stored tubers and a very significant linearrelationship existed between RS content and chip color index (CCI) of the tubers. Furtheranalysis elucidated that when tubers stored at 4℃, the activities of ADP glucosepyrophosphorylase (AGPase), UDP glucose pyrophosphorylase (UGPase) and sucrose synthase(SuSy) were negatively exponential to the RS content significantly while that of acidinvertase and alkaline invertase was significantly linear to RS content. It suggestedthat these enzymes could play main roles in the cold sweetening of potato tubers throughregulating starch-sugar metabolism.
基金Supported by Special Project for Breeding and Cultivation of GMO Varieties of Ministry of Agriculture (2011ZX08001-001, 2011ZX08001-004)Major Science and Technology Program of Hunan, China (2011FJ1002-2)+1 种基金Natural Science Foundation of Hunan, China (09JJ3046 )Science and Technology Innovation Program of Hunan Academy of Agricultural Sciences (2009hnnkycx17)~~
文摘[Objective] This study aimed to analyze the effects of temperature on the expression of AGPase isoform genes in rice endosperm during milk stage. [Method] Different temperature treatments （33 and 25 ℃ of daily mean temperature for high and normal temperature treatments, respectively） and the real-time fluorescence quantitative PCR （ FQPCR） were used to analyze the expression patterns of seven isoforms （AGPS1, AGPS2a, AGPS2b, AGPL1, AGPL2, AGPL3 and AGPL4） of ADPglucose pyrophosphorylase （AGPase） which was the key enzyme in starch synthesis and metabolism in rice endosperm of two rice varieties Teqing and Thai Fragrant Rice. [Result] The AGPase isoforms AGPS2b, AGPL2 and AGPL3 had much higher expression than the other four isoforms, thus they were thought to be the main expression patterns of AGPase in rice endosperm. The relative expressions of AGPL2 was the highest among all the isoforms. The relative expressions of AGPS2b, AGPL2 and AGPL3 were higher in the normal temperature treatment than in the high temperature treatment in both rice varieties. The relative expression of the three enzyme genes in milk stages in Teqing was higher than those in Thai Fragrant Rice under different temperature treatments. [Conclusion] This study provides a theoretical basis for further use of molecular biology techniques to cultivate stable high-quality rice varieties.
文摘木薯是重要的热带作物,具有高淀粉积累等特点,但其高效积累机制尚不明确。为研究腺苷二磷酸葡萄糖焦磷酸化酶(AGPase)大亚基对木薯淀粉积累的调控作用,本研究通过RT-PCR技术对木薯AGPase5个大亚基基因(MeAGPL1~MeAGPL5)进行筛选,发现MeAGPL3基因在木薯块根中高表达且受100μmol/L外源ABA正向调控;克隆了该基因2455 bp 5’侧翼序列,利用该序列及4个不同长度的5’端截短片段分别与β-葡萄糖醛酸酶(GUS)基因融合构建表达载体,转化本氏烟草,通过检测各转基因烟草GUS蛋白活性,发现-1至-1711 bp序列具有最佳的启动活性。利用100μmol/L外源ABA处理各转基因烟草株系,分析处理前后GUS蛋白活性变化,发现ABA信号响应元件分布于-1711至-2150区域。本研究为从转录调控角度阐释木薯淀粉高效积累机制提供理论支撑。
