州河鲤、建鲤和框鳞镜鲤3个群体同工酶的分析

使用水平式淀粉凝胶电泳法,对采自天津地区的州河鲤、建鲤和框鳞镜鲤3个群体进行了AAT、α-GPD、GPI、IDH、MDH和PGM共6种同工酶以及肌浆蛋白(PROT)的电泳分析。结果表明:在检测出的12个基因座位中,州河鲤群体中存在变异的是α-GPD*、GPI*、MDH-2*、PGM*、PROT*,建鲤群体中存在变异的是α-GPD*、GPI*和PGM*,框鳞镜鲤群体中存在变异是α-GPD*、GPI*、PGM*和PROT*;州河鲤、建鲤、框鳞镜鲤的多态基因座位比例(P0.99)分别为41.67%、25.00%和33.33%,平均杂合度预期值(He)分别为0.0449、0.0749、0.0518;PGM*可以作为区分3个群体的标记基因座位,州河鲤群体中*c/c基因型占85.71%,建鲤群体中*b/c基因型占65.71%,框鳞镜鲤群体中*b/b基因型占56.67%。     

非等步长PGM(1,1)模型及其在工程中的应用

针对工程中的非等步长数据,文章在PGM(1,1)模型基础上,提出了非等步长观测数据序列的灰色PGM(1,1)模型建模方法,并通过建立土体粘聚力与含盐量同含水量的比值的灰色PGM(1,1)模型,说明非等步长PGM(1,1)模型在工程中具有很强的适用性。     

Identification,Characteristics and Function of Phosphoglucomutase (PGM) in the Agar Biosynthesis and Carbon Flux in the Agarophyte Gracilariopsis lemaneiformis (Rhodophyta)

Agar is widely applied across the food, pharmaceutical and biotechnology industries, owing to its various bioactive functions. To better understand the agar biosynthesis in commercial seaweed Gracilariopsis lemaneiformis, the activities of four enzymes participating in the agar biosynthesis were detected, and phosphoglucomutase (PGM) was confirmed as highly correlated with agar accumulation. Three genes of PGM (GlPGM1, GlPGM2 and GlPGM3) were identified from the G. lemaneiformis genome. The subcellular localization analysis validated that GlPGM1 was located in the chloroplast and GlPGM3 was not significantly distributed in the organelles. Both the GlPGM1 and GlPGM3 protein levels showed a remarkable consistency with the agar variations, and GlPGM3 may participate in the carbon flux between (iso)floridoside, floridean starch and agar synthesis. After treatment with the PGM inhibitor, the agar and floridean starch contents and the activities of floridean starch synthase were significantly decreased; products identified in the Calvin cycle, the pentose phosphate pathway, the Embden-Meyerhof-Parnas pathway and the tricarboxylic acid cycle were depressed; however, lipids, phenolic acids and the intermediate metabolites, fructose-1,6-phosphate were upregulated. These findings reveal the essential role of PGM in regulating the carbon flux between agar and other carbohydrates in G. lemaneiformis, providing a guide for the artificial regulation of agar accumulation.     

Molecular approaches for enhancing sweetness in fruits and vegetables

The quality of fruits and vegetables is mainly dependant on the sweetness determined by the level of soluble sugars such as glucose, fructose and sucrose. Other fruit quality parameters include Brix content, acidity, aroma, color, size and shape. Total sugar content in fruits and vegetables is a function of genetic, nutritional, environmental and developmental factors. Understanding the factors controlling sweetness is important to design strategies for enhancing quality of fruits and vegetables. Modifying the activity of enzymes in carbohydrate metabolism such as sucrose synthase (SuSy), acid invertase, ADP-glucose pyrophosphorylase (AGPase), sucrose phosphate synthase (SPS) and sucrose transporters were found to influence carbohydrate partitioning and sucrose accumulation in sink tissues of several food crops. Plant based taste-modifying sweet proteins such as brazzein, cucurmin, mabinlin, monellin, miraculin, neoculin and thaumatin have potential application for developing transgenic plants to improve the sweetness and quality of fruits and vegetables. The present review envisages various cultural, breeding and molecular approaches used for enhancing sugar content and sweetness in fruits and vegetables.     

五种海洋生物葡萄糖磷酸变位酶和磷酸葡萄糖异构酶的同工酶分析

采用水平淀粉凝胶电泳方法对虾夷马粪海胆（Strongylocentrotus intermedius）、刺参（Apostichopus japonicus Selenka）、半滑舌鳎（Cynoglossus semilaevis）、文蛤（Meretrix meretrix）和虾夷扇贝（Pecten yessoensis）不同组织中的葡萄糖磷酸变位酶（PGM）和磷酸葡萄糖异构酶（GPI）进行了检测分析。结果发现，虾夷马粪海胆肌肉组织和成熟性腺组织中的PGM有较强的表达活性和表达位点差异，两种组织中GPI活性稍差。刺参的肠道组织和肌肉组织只有PGM和GPI表达活性的差异，而无位点差异。半滑舌鳎肌肉组织检测到两个PGM位点，三个GPI位点。文蛤闭壳肌组织PGM表现出非常高的多态性，而GPI表现为单态。虾夷扇贝闭壳肌组织的PGM和GPI各只检测到一个位点，遗传变异程度比较低。以PGM和GPI为指标，对我国北方5种重要海水养殖品种的同工酶遗传变异水平和其它相关遗传参数进行了分析，对群体遗传结构可能的变化规律以及与某些性状的相关性进行了探讨，这些参数对它们的遗传选育有一定的指导作用。     

利用淀粉凝胶电泳技术鉴定外源DNA导入后代

利用淀粉凝胶电泳技术，对外源ＤＮＡ直接导入栽培大豆的变异后代，进行了磷酸己糖异构化酶（ＧＰＩ）、异柠檬酸脱氢酶（ＩＤＨ）和葡糖磷酸变位酶（ＰＧＭ）的同工酶酶谱分析。实验结果表明：将向日葵的ＤＮＡ导入栽培大豆后，三种酶的谱带清楚，后代与受体及供体间谱带存在差异。有的出现了供体特异带，有的出现了供体和受体所不含有的新型带，有的酶谱带加强或减弱，这说明外源ＤＮＡ已导入到受体基因组中，并在不同程度和不同方式上得到了表达。