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1.
 选用蒸煮食味品质不同的3个粳稻品种,利用温室高温和自然常温,研究了灌浆成熟期温度对水稻籽粒淀粉合成关键酶活性及蒸煮食味品质的影响。结果表明,灌浆成熟期高温条件下,水稻籽粒蛋白质含量提高,直链淀粉含量和味度值降低,劣质品种提高或降低的程度大于优质品种;RVA谱特性对灌浆成熟期温度的反应因品种和特性而异;灌浆过程中,籽粒ADPG焦磷酸化酶、可溶性淀粉合成酶和淀粉分支酶活性随灌浆进程,酶活性逐渐增加,达到峰值以后,酶活性又逐渐下降,呈单峰曲线,但不同品种酶活性达到峰值的时间和同一时期的酶活性大小有差异;ADPG焦磷酸化酶和可溶性淀粉合成酶的活性表现对温度的影响反应较为迟钝,而淀粉分支酶活性表现对温度变化的反应较为敏感,温度过高过低都降低该酶活性。  相似文献   

2.
水稻胚乳淀粉合成相关酶的结构、功能及其互作研究进展   总被引:3,自引:2,他引:1  
淀粉作为稻米最主要的储藏物质,其生物合成过程直接影响水稻的产量和品质。水稻淀粉的生物合成在造粉体中通过一系列酶促反应完成。本文综述了淀粉合成过程中ADP-葡萄糖焦磷酸化酶(AGPase)、淀粉合酶(SSs)、淀粉分支酶(BE)及淀粉脱支酶(DBE)的结构、功能以及各酶之间的相互作用的最新研究进展,以期为稻米品质改良提供理论参考依据。  相似文献   

3.
综述了禾本科作物籽粒淀粉化学组成及其生物合成的基本原理.籽粒淀粉主要由直链淀粉和支链淀粉组成,直链淀粉合成主要受二磷酸葡萄糖焦磷酸化酶( AGPP)、直链淀粉合成酶(GBSS)和淀粉去分支酶(DBE)共同作用,而支链淀粉除受以上酶的催化外还受淀粉分支酶(SBE)的影响.  相似文献   

4.
Summary Potatoes with an applied load of 196 N (20 kgf) were stored at 7°C for 60 days. The sugar contents (glucose, fructose and sucrose), invertase, UDP-glucose pyrophosphorylase (UGPase) and sucrose 6-phosphate synthase (SPS) of the potatoes were measured at intervals during storage. The aim of this study was to determine whether static loading affects the sugar contents and enzymes levels in potatoes during storage. Static loading increased the glucose, fructose and reducing sugar contents, as well as the invertase activity of potatoes during storage. The reducing sugar content of static loaded potatoes was correlated (P<0.01) with the invertase activity.  相似文献   

5.
Photosynthetic product in rice plant is transported to grains mainly in the form of sucrose. Sucrose in the grains eventually becomes starch through a series of enzymatic reactions [1-2]. The starch weight accounts for 90% of the brown rice [3-4], so the course of the rice grain filling is the biochemical process in which starch is mainly formed, and the factor of light is indispensable at the course. Much research has been conducted to study the influence of the light on the grain starch synt…  相似文献   

6.
In order to determine the reasons for the differences in structure between starch from a normal and a low-amylopectin maize variety the activities of all the enzymes in the committed pathway of starch synthesis were studied throughout kernel development. Levels of ADP glucose pyrophosphorylase and starch synthase activity were found to be broadly similar between the two varieties but the low-amylopectin starch (LAPS) maize variety showed dramatically reduced starch branching enzyme activity, with an almost total absence of the branching enzyme II isoform. Scanning electron microscopy showed a significant alteration in the morphology of the starch granules of the low-amylopectin maize. The results suggest that the increased amylose and the reduction of high molecular weight amylopectin in the LAPS starch results from the absence of the branching enzyme II isoform. This evidence supports the theory that the different branching enzyme isoforms contribute separately to the synthesis and final structure of amylopectin.  相似文献   

7.
Summary Tissue from developing tubers, mature tubers, and mature tubers that had been stored at 4°C, was killed and extracted with trichloroacetic acid in diethylether. Inorganic pyrophosphate was detected in the aqueous phase of the extracts with pyrophosphate fructose-6-phosphate-1-phosphotransferase. No pyrophosphate could be detected in extracts that had been pretreated with pyrophosphatase. Pyrophosphate contents of about 3–12 nmol/g fresh weight were found. It is suggested that potato tubers contain sufficient pyrophosphate to allow the enzyme UDPglucose pyrophosphorylase to convert UDPglucose to glucose-1-phosphate during cucrose breakdown.  相似文献   

8.
以弱筋小麦扬麦9号为材料,在缺磷土壤(速效磷含量4.1mg/kg)上进行施磷量试验,研究施磷量对小麦籽粒淀粉合成、积累及相关酶活性的影响。结果表明。在施磷(P2O5)0~108kg/ha范围内,增加施磷量,籽粒直链淀粉、支链淀粉、总淀粉积累量、积累速率上升,旗叶蔗糖磷酸合成酶(SPS)活性和蔗糖含量提高,籽粒蔗糖合成酶(SS)活性增强。籽粒蔗糖含量提高。籽粒ADPG焦磷酸化酶(AGPP)、可溶性淀粉合成酶(ssS)、束缚态淀粉舍成酶(GBSS)活性提高,成熟籽粒直链淀粉、支链淀粉、总淀粉含量下降。施磷量超过108kg/ha后,直链淀粉、支链淀粉、总淀粉积累量、积累速率及蔗糖含量、SPS、SS、AGPP、SSS、GBSS酶活性呈下降趋势。  相似文献   

9.
Fifteen potato (Solanum tuberosum L.) clones with varying resistance to cold-induced sweetening were analysed for vacuolar acid invertase (AcInv, EC 3.2.1.26) and UDP-Glc pyrophosphorylase (UGPase; EC 2.7.7.9) activities related to their ability to accumulate sugars following cold storage (4 C). The UGPase isozyme profiles for each clone were also determined. Immunoblot analysis demonstrated a 55 kD protein, in seven of the 15 clones, that reacted with UGPase antisera in addition to the 53 kD UGPase subunit previously reported. The UGPase activity of these clones was significantly lower than that of the “single subunit” clones. Basal AcInv activity showed a positive correlation to the Glc:Suc ratio across the clones that was moderately significant before and after cold temperature storage. The activity of UGPase, which limits the rate of Suc formation, was of secondary importance in limiting the rate of hexogenesis when vacuolar AcInv activity was excessive. It is suggested that with the potato clones from this breeding program that AcInv (and its inhibitor) plays a dominant role in the hexogenic pathway by regulating the hexose:Suc ratio. The finding of a new protein that is reactive with UGPase antisera may prove to play an important function in the regulation of Suc formation in potatoes.  相似文献   

10.
The progenies differed in amylose and protein contents in grains, which derived from a rice cross, Dongnong 423×Toukei 180, were used to study changes in the activities of ADP-glucose pyrophosphorylase (AGPP), soluble starch synthetase (SSS), starch branching enzyme (SBE) and glutamine synthetase (GS) in rice grains during grain filling. The activities of AGPP, SSS and SBE gradually increased and then declined as a single-peak curve with the process of grain filling in the progenies with high and low amylose contents in grains. The progenies with high amylose content peaked earlier in the AGPP, SSS and SBE activities and had higher AGPP, SSS and SBE activities at the early grain filling stage than those with low amylose content. The GS activity peaked earlier and was higher at the late stage of grain filling in the progenies with high protein content than in those with low protein content. It is suggested that the activities of key enzymes for starch synthesis and glutamine synthetase could be changed in oriented breeding for amylose and protein contents in grains.  相似文献   

11.
An approach has been developed to screen a large number of potato clones for cold induced sweetening (CIS) resistance in breeding programs. Two key enzymes responsible for reducing sugar accumulation during cold storage were identified. Clones with the A-II isozymes of UDP-glucose pyrophosphorylase coupled with low activity of vacuolar acid invertase enzyme had increased resistance to CIS by forming less suc, which is subsequently hydrolyzed to the undesirable reducing sugars, glc and fru. Six named cultivars and 192 genetically diverse clones from various breeding programs in USA were analyzed over two years for the two key enzymes and sugar concentration in cold stored tubers. The predictability for CIS resistance during cold storage was 94% both years. Clones classified as class A accumulated low concentration of reducing sugar glc during cold storage. It is suggested that these two predictor enzymes can be used for screening parents and selections in potato breeding program.  相似文献   

12.
 以东农423和藤系180为试材,籽粒直链淀粉和蛋白质含量为选择指标,通过逐代的定向选择形成了遗传背景相近且直链淀粉和蛋白质含量有显著差异的杂种后代,并对水稻灌浆成熟过程中籽粒ADPG焦磷酸化酶、可溶性淀粉合酶、淀粉分支酶、谷氨酰胺合成酶活性变化进行了初步研究。高直链淀粉含量杂交后代的籽粒ADPG焦磷酸化酶、可溶性淀粉合酶、淀粉分支酶活性峰值显著或极显著高于低直链淀粉含量后代,而且在籽粒灌浆前期蛋白质含量高的后代籽粒谷氨酰胺合成酶活性显著或极显著高于蛋白质含量低的后代。因此,通过直链淀粉和蛋白质含量的连续定向选择可以显著提高或降低灌浆过程中的籽粒碳氮代谢关键酶活性。  相似文献   

13.
【目的】 研究水稻EARLY STARVATION1 (OsESV1)基因对水稻淀粉代谢的影响。【方法】 通过CRISPR-Cas9技术获得osesv1突变体,考查osesv1的表型及胚乳淀粉的理化特性,分析OsESV1的表达特性及相关功能。【结果】 OsESV1蛋白在植物界中十分保守。osesv1突变体株高、穗长、每穗粒数低于野生型,分蘖数显著多于野生型,叶片中淀粉含量显著下降,籽粒中的直链淀粉含量上升,而总淀粉含量无明显变化。OsESV1呈组成型表达,并且具有昼夜节律表达的特征。OsESV1蛋白定位在叶绿体内且呈点状分布。酵母双杂交和双分子荧光互补实验结果表明OsESV1蛋白可以与ADP-葡萄糖焦磷酸化酶小亚基(OsAGPS) 2a和OsAGPS1互作。【结论】 OsESV1基因影响水稻叶片的淀粉合成途径,而对胚乳淀粉合成的影响不明显。  相似文献   

14.
The common buckwheat ‘cv. Fengtian 1’ (FT1), ‘cv. Yuqiao 4’ (YQ4), ‘cv. Dingtian 2 (DT2)’, and ‘cv. Tongliao (TL)’ were selected to investigate the characteristics of starch synthesis and grain filling. The chlorophyll and chlorophyll a/b contents of leaves in the third stem showed a steady downward trend with the growth of common buckwheat. Whereas, FT1, YQ4 and DT2 showed higher chlorophyll content than that of TL at 7d and 14d. The activity of soluble starch synthase(SSS) and adenosine diphosphate glucose pyrophosphorylase (ADPGP) in the four tested varieties showed a rapid upward trend until 14 days after heading but then rapidly decreased until 21 days after heading. The average adenosine diphosphate glucose pyrophosphorylase activities of FT1, YQ4 and DT2 were higher than TL, while the average soluble starch synthase activities were similar among the four tested varieties. Consistently, the four tested varieties showed rapid accumulation of starch, amylose, and amylopectin during the prefilling stage, but no difference of starch content was found at maturity. The filling process of the four common buckwheat varieties exhibited an “S” curve. The Richards equation was utilized to evaluate the grain-filling process of common buckwheat. YQ4 showed the largest values of initial growth power (R0). The time reaching the maximum grain-filling rate (tmax.G) of FT1 was the longest, and the maximum grain-filling rate (Gmax) of DT2 was the fastest.  相似文献   

15.
采用田间试验和生化分析等方法研究了密度对饲用杂交稻威优56的几种酶活性的影响及其与产量和蛋白质含量的关系。结果表明,密度降低能提高叶片的磷酸烯醇式丙酮酸羧化酶(PEPC)、谷氨酰胺合成酶(GS)以及籽粒的腺苷二磷酸葡萄糖焦磷酸化酶(ADPGP)和GS的活性,且其叶片和籽粒的非蛋白氮、蛋白氮和全氮含量亦增加,从而使糙米蛋白质含量增加。合理密度为30万蔸/hm^2,其产量最高和糙米蛋白质含量较高,因此有利于饲料稻威优56高产与高蛋白质含量协同形成。这与在此密度下籽粒蔗糖合成酶(SS)和叶片蔗糖磷酸合成酶(SPS)活性最高,以及籽粒和叶片的PEPC和GS活性较高相关。  相似文献   

16.
应用Biolog Eco微平板法研究了转无机焦磷酸化酶基因甘蔗对根际土壤微生物多样性的影响.结果表明:转基因甘蔗根际土壤微生物利用单一碳源能力(A WCD)在整个培养过程都显著高于非转基因甘蔗的根际土壤微生物;转基因甘蔗和非转基因甘蔗根际土壤样品的Simpson指数(I/D,优势度)、Shannon-Wiener指数(H,物种丰富度)、Mclntosh指数(U,物种均一性)均存在差异,其中转基因甘蔗根际土壤微生物的Simpson指数、Mclntosh指数均显著高于非转基因甘蔗土壤微生物;主成分分析也表明转基因甘蔗与非转基因甘蔗土壤微生物对不同的碳源有特异利用,起分异作用的主要碳源是糖类,其次是脂肪酸和脂类.表明转基因甘蔗根系在生长期可能诱导了具有某些特定生理特征的微生物群落的发展,因此改变了土壤微生物群落的功能多样性,总体表现较高的活性.  相似文献   

17.
ADP-Glucose pyrophosphorylase (AGPase) is a rate-limiting enzyme participating in starch biosynthesis, which may be responsible for the filling rate and starch accumulation in the developing rice kernel. However, it is still unknown whether the naturally occurring variation in the sequence of ADP-Glucose pyrophosphorylase of rice (OsAGP) is related to the grain weight (GW). In this study, we discovered a total of 38 single nucleotide polymorphisms (SNPs) and insertions/deletions (InDels) in the partial sequences of six OsAGP isoform genes from 30 rice accessions with diverse agronomic traits. We then developed ten cleaved amplified polymorphic sequence (CAPS) and derived CAPS (dCAPS) markers for genotyping the SNPs and InDels for an association mapping population consisting of 416 rice accessions. Candidate gene association study indicated that an InDel of OsAGPL4 was associated with GW in two environments and an SNP of OsAGPL2 was associated with GW in one environment. Each gene marker only explained 1% of the variation of GW, thus it could be concluded that both genes contributed little to GW of rice. However, the markers identified in this study could be used for tagging other traits of interests and in molecular breeding.  相似文献   

18.
《Plant Production Science》2013,16(3):178-183
Abstract

Leaf sheaths of rice plants are known to temporarily accumulate starch prior to heading, which is subsequently remobilized and transported into the panicle after heading. We investigated the time course for both carbohydrate content and steady state mRNA levels of enzymes related to starch and sucrose metabolism in the rice leaf sheath (Oryza sativa L. cv. Nipponbare). Leaf sheaths from the second leaf below the flag leaf accumulated high levels of starch before heading but they rapidly decreased after heading. In contrast, the flag leaf sheath did not accumulate as much starch. In the second leaf sheath, the mRNA levels of enzymes involved in starch synthesis, ADP glucose pyrophosphorylase (EC 2. 7. 7. 27), soluble starch synthase (EC 2. 4. 1.21) and branching enzyme (EC 2. 4. 1. 18) were high before heading, which coincided with rapid accumulation of starch. The mRNA levels of sucrose synthesis enzymes, cytosolic FBPase (EC 3. 1. 3. 11) and sucrose phosphate synthase (EC 2. 4. 1. 14), and the sucrose transporter (OsSUTI) increased at the time of heading, which was largely coincident with a decrease in the mRNA levels of starch synthesis enzymes. In the flag leaf sheaths, changes in mRNA levels of starch synthesis enzymes were not pronounced, however mRNA levels of sucrose synthesis enzymes and the sucrose transporter showed a clear increase throughout the heading period. The different characteristics observed between the two leaf sheaths will be discussed in relation to the sink to source transition.  相似文献   

19.
刘晓庆  王萍  詹延廷  王月  杨阳  李昊  董学会 《玉米科学》2019,27(1):54-61,68
以玉米自交系B73为试验材料,研究施用外源乙烯之后对胚乳内淀粉合成的影响。结果表明,在玉米10展叶时期施用400 mg/L的乙烯利水溶液显著降低玉米百粒重和淀粉含量。淀粉合成相关酶活性测定结果表明,处理组中ADP葡萄糖焦磷酸化酶、可溶性淀粉合成酶、淀粉分支酶、蔗糖合成酶的活性均显著下降。淀粉合成相关基因表达量分析结果表明,处理组中ADP葡萄糖焦磷酸化酶基因ZmSH2、可溶性淀粉合成酶基因ZmSS1、蔗糖合成酶的基因ZmSH1表达量低于对照组。由此推测,外源乙烯通过调控淀粉合成相关基因的表达与酶的活性影响玉米胚乳内淀粉的合成。  相似文献   

20.
正Os Pho1 in Zhonghua 11(ZH11) was edited using the clustered regularly interspaced short palindromic repeatsassociated endonuclease 9(CRISPR/Cas9) system. Two homozygous T1 mutants(cr-pho1-34 and cr-pho1-37) displayed a chalky endosperm with a white core, which significantly decreased 1000-grain weight.  相似文献   

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