不同甘蓝型油菜高含油量种质资源的脂肪酸成分分析

甘蓝型油菜是我国最为重要的油料作物之一.目前我国面临着植物油严重不足的局面.提高含油量是目前甘蓝型油菜育种的主要方向之一.目前.我国育种工作者已经筛选出了大量含油量超过50%的甘蓝型油菜种质.本文对两种类型的高含油量甘蓝型油菜种质进行了脂肪酸组分分析,结果显示芥酸含量高的种质和芥酸含量低的种质的脂肪酸在菜籽油中变化范围和平均值明显不同.油酸和亚油酸在低芥酸高含油量甘蓝型油菜种质中的含量较高,约占整个油分的80%左右,其他脂肪酸组分则在10%以下;而芥酸则是高芥酸高含油量种质的最主要的成分,约占整个油分的44%左右,油酸、亚油酸等的含量则均在10%左右.相关性分析表明:芥酸和其他脂肪酸之间呈现显著负相关,因此.可以通过降低高芥酸油菜种质中的芥酸含量来提高比如油酸和亚油酸的含量.从而使这些种质的油分更适合人类的健康.     

植物脂肪酸脱饱和酶特性及转基因研究进展

脂肪酸代谢是有机体的基本代谢之一。植物体内首先合成的是饱和脂肪酸,然后在脂肪酸脱饱和酶作用下形成不饱和脂肪酸。目前已经从很多植物中克隆到了脂肪酸合成相关的酶,并对其功能进行了鉴定。详细介绍了近年来应用基因工程技术对植物油中不饱和脂肪酸含量和组分进行改造所取得的进展,并对其在植物抗性育种中的应用进行了展望。     

植物脂肪酸代谢途径遗传调控的研究进展

目前,利用传统育种方法改良油料作物脂肪酸组分已取得巨大成功,通过有性杂交、X-射线或EMS处理等方法都可用来修饰存在于油菜中脂肪酸的性质。国外已培育出高棕榈酸、高或低亚油酸、高油酸和无芥酸的油菜品种。但由于油料作物基因池(Gene Pool)的局限性使得育种学家不得不寻找其他种质资源。随着基因克隆和遗传转化技术的进步,通过基因工程改良油料作物品质已成可能。本文主要介绍了植物脂肪酸的代谢途径以及通过操纵TAG的生物合成来改变油的成分等研究,其中主要包括脂肪酸链长度的改良、饱和度改良、增加脂肪酸含量以及新的不饱和脂肪酸的改良等方面。不久的将来,转基因油料作物中将会产生更有价值的脂肪酸造福于人类。     

普通菜豆基因组学及抗炭疽病遗传研究进展

普通菜豆是重要的食用豆类之一,在世界各大洲普遍种植。近年来,普通菜豆在遗传图谱构建、新标记开发与利用、抗性基因定位以及比较基因组学等方面取得了很大进展。遗传连锁图谱的构建是基因定位与克隆的基础,是遗传研究中的重要内容;利用分子连锁图谱鉴定、标记和定位抗病基因将在种质改良和分子标记辅助育种方面发挥重要作用。豆科植物比较基因组学的研究成果为菜豆遗传连锁图谱的发展提供了新的思路。本文从普通菜豆遗传连锁图谱的获得、普通菜豆与大豆同线性比较以及抗炭疽病基因定位等方面进行了综述,以期为普通菜豆遗传改良和抗病育种提供参考。 关键词：普通菜豆;遗传连锁图;同线性比较;抗菜豆炭疽病     

大豆过敏蛋白与品种改良

食物过敏是一个全世界关注的公共卫生问题。大豆蛋白在食品加工业的广泛应用,对大豆敏感人群带来了潜在的威胁。如何降低大豆过敏原含量提升大豆食品安全已成为日益关注的问题。大豆种子过敏蛋白包括种子贮存蛋白、结构蛋白和防御相关蛋白,其中7S 伴球蛋白的多肽片段Gly m Bd 28K, Gly m Bd 30K和Gly m Bd 60K是三种主要的过敏原。目前通过对过敏蛋白的理化性质、过敏原性和基因结构的认识,运用食品加工工艺、传统育种及基因工程技术等方法,在减少大豆和大豆产品的过敏原性方面已取得一定的进展。本文拟从大豆过敏原的分类、主要过敏原Gly m Bd 28K和Gly m Bd 30K的理化性质及基因结构、大豆过敏蛋白在遗传改良中的应用对大豆过敏蛋白进行综述。     

中品661 EMS诱变后代高蛋白的选择效果及新种质创制

大豆是重要的植物蛋白来源,高蛋白大豆种质创新对于我国食用大豆育种及优异基因发掘具有重要意义。为获得优异高蛋白大豆资源,本研究利用NIR法测定EMS诱变中品661(Zp661)M2～M7籽粒的蛋白质含量,系统分析连续选择对蛋白变异的影响,旨在创制高蛋白优异种质,为大豆品质改良育种提供优异资源。结果表明,1971个M2单株籽粒蛋白质含量变异幅度为34.96%～50.16%,平均值为42.97%,较野生型(40.88%)提高5.11%,其中17.65%的M2单株籽粒蛋白质含量高于45%。M2高蛋白含量个体经过定向连续选择,整体呈下降趋势;相比之下,M2低蛋白含量个体定向选出的高蛋白含量种质遗传增益效果明显。在M7获得9个高蛋白含量稳定种质(m1～m9),平均蛋白质含量为48.17%,较野生型(41.19%)平均提高16.94%,遗传增益为7.23%。其中m1～m7来自M2高蛋白质含量个体20722(47.21%),而m8～m9来自M2低蛋白质含量个体3442(38.51%)。这些高蛋白纯合种质的农艺性状相关性分析发现,m2、m4和m5的蛋白质含量分别与百粒重和单株粒重呈显著正相关,说明通过选择可以实现蛋白质含量与产量的同时提高,获得高产优质的优异种质。     

大豆种子蛋白和油脂含量调控的研究进展

作为重要的粮油饲兼用作物,大豆为世界膳食提供高达约71%的蛋白质和29%的油脂。随着人口不断增长和大豆消费需求的不断提高,在有限的耕地面积和单产条件下,大豆品质的遗传改良则更具重要意义。该文综述了大豆种子蛋白和油脂含量两个重要品质性状调控的研究进展,总结了调控大豆蛋白和油脂合成的关键酶和转录因子及因子间的相互作用,并根据蛋白和油脂合成代谢调控途径中关键酶和转录因子作用机制,绘制了大豆蛋白和油脂合成代谢的分子调控网络。此外,该文还讨论了当前大豆种子蛋白油脂含量调控研究存在的瓶颈及对策,以期为大豆种子品质的遗传改良和高产品种培育提供参考。     

国家种质库保存国外大豆种质的分析研究

为促进国外引进种质的有效利用,对国家长期库中引进的2156份国外大豆种质的来源、主要农艺性状、蛋白质及脂肪含量进行了分析.结果表明:国家长期库现存的引进大豆种质主要来自美国等国家,多表现为生育期较长、紫花、棕毛、无限结荚习性、种皮黄、多深色脐、百粒重中等,蛋白质含量多介于40.01%～45.00%之间,油分含量多介于18.01%～22.0%之间;株高的变异系数最高,蛋白质及脂肪含量的变异系数较低;7个质量性状遗传多样性平均值低于国内微核心种质.     

醋豆与大豆中脂肪酸含量的比较及营养学意义

目的:分析比较醋浸泡后大豆中的脂肪酸(FA)含量的变化,为大豆开发提供实验数据.方法:用石油醚提取总脂肪,甲基化后用气相色谱分析脂肪酸的含量分布.结果:醋浸泡28d后,醋豆总脂肪的相对含量趋于稳定,其中醋豆和大豆相比,软脂酸下降了1.21%,硬脂酸下降了0.58%,油酸下降了3.01%,亚油酸增加了1.32%,亚麻酸增加了6.32%.结论:饱和脂肪酸(SFA)和单不饱和脂肪酸的相对含量下降,多不饱和脂肪酸(PUFA)相对含量显著升高.醋大豆及大豆的多不饱和脂肪酸与饱和脂肪酸相对含量的比值分别为4.11和3.2.上述变化的从营养学或生理学的角度,更符合人体需求.     

苏子生物学特性初步研究

通过对甘肃东、南部不同粒色(分浅灰和红褐两类)的苏子地方品种播期、播深、控制日照长度试验和详细观察,化验分析,研究了苏子的幼苗习性,成株期习性,开花结果与感光习性,及种子形态、油分含量、油中各种脂肪酸含量。基本弄清了与苏子栽培育种有关的性状。     

Mutant alleles of <Emphasis Type="Italic">FAD2-1A</Emphasis> and <Emphasis Type="Italic">FAD2-1B</Emphasis>combine to produce soybeans with the high oleic acid seed oil trait

Background  

The alteration of fatty acid profiles in soybean [Glycine max (L.) Merr.] to improve soybean oil quality is an important and evolving theme in soybean research to meet nutritional needs and industrial criteria in the modern market. Soybean oil with elevated oleic acid is desirable because this monounsaturated fatty acid improves the nutrition and oxidative stability of the oil. Commodity soybean oil typically contains 20% oleic acid and the target for high oleic acid soybean oil is approximately 80% of the oil; previous conventional plant breeding research to raise the oleic acid level to just 50-60% of the oil was hindered by the genetic complexity and environmental instability of the trait. The objective of this work was to create the high oleic acid trait in soybeans by identifying and combining mutations in two delta-twelve fatty acid desaturase genes, FAD2-1A and FAD2-1B.     

Metabolic engineering of soybean seeds for enhanced vitamin E tocochromanol content and effects on oil antioxidant properties in polyunsaturated fatty acid-rich germplasm

Soybean seeds produce oil enriched in oxidatively unstable polyunsaturated fatty acids (PUFAs) and are also a potential biotechnological platform for synthesis of oils with nutritional omega-3 PUFAs. In this study, we engineered soybeans for seed-specific expression of a barley homogentisate geranylgeranyl transferase (HGGT) transgene alone and with a soybean γ-tocopherol methyltransferase (γ-TMT) transgene. Seeds for HGGT-expressing lines had 8- to 10-fold increases in total vitamin E tocochromanols, principally as tocotrienols, with little effect on seed oil or protein concentrations. Tocochromanols were primarily in δ- and γ-forms, which were shifted largely to α- and β-tocochromanols with γ-TMT co-expression. We tested whether oxidative stability of conventional or PUFA-enhanced soybean oil could be improved by metabolic engineering for increased vitamin E antioxidants. Selected lines were crossed with a stearidonic acid (SDA, 18:4^Δ6,9,12,15)-producing line, resulting in progeny with oil enriched in SDA and α- or γ-linoleic acid (ALA, 18:3^Δ9,12,15 or GLA, 18:3^Δ6,9,12), from transgene segregation. Oil extracted from HGGT-expressing lines had ≥6-fold increase in free radical scavenging activity compared to controls. However, the oxidative stability index of oil from vitamin E-enhanced lines was ~15% lower than that of oil from non-engineered seeds and nearly the same or modestly increased in oil from the GLA, ALA and SDA backgrounds relative to controls. These findings show that soybean is an effective platform for producing high levels of free-radical scavenging vitamin E antioxidants, but this trait may have negative effects on oxidative stability of conventional oil or only modest improvement of the oxidative stability of PUFA-enhanced oil.     

Dietary protein and fatty acid composition of liver lipids in the rat

In order to compare the effects of different sources of dietary protein on the fatty acid composition of phosphatidylcholines (PC), phosphatidylethanolamines (PE), phosphatidylinositols (PI), cholesteryl esters and triacylglycerols, male rats were fed for a 4-week period on cholesterol-free, or cholesterol-containing, diets based on casein, or soybean protein and olive oil. The most conspicuous difference observed was the occurrence of significantly higher levels of 5,8,11-eicosatrienoic acid, 20:3 (n - 9), in the different lipid classes of casein-fed, compared with soybean protein-fed, animals. In the PI fraction of livers from the groups of rats fed casein diet, this fatty acid amounted to between 9.9 and 13.3% by weight of the total fatty acids. Phospholipids from livers of casein-fed rats contained increased levels of oleic acid, 18:1 (n - 9) (in PC and PE) and reduced levels of stearic acid (18:0). Moreover, in this group of rats PI contained a reduced level of arachidonic acid, 20:4 (n - 6). A casein-related decrease in the linoleic acid, 18:2 (n - 6), content of PC and PE was observed only in the rats fed on cholesterol-free diet. Effects on the fatty acid composition were also observed in the triacyglycerol and cholesteryl ester fractions, in which the rats fed casein diet showed higher levels of palmitoleic acid, 16:1 (n - 7) (cholesterol-supplemented diet) and lower values for linoleic acid, than the soybean protein-fed rats.     

Influences of stearidonic acid-enriched soybean oil on the blood and organ biochemical parameters in rats

In this study, we administered various diets of stearidonic acid (SDA, 18:4n?3) soybean oil to rats and examined the subsequent blood and organ biochemical parameters. Male Wistar rats (seven rats/group, six groups total) were fed diets supplemented with a test oil for 4 weeks. Diets containing test oils were: FFC diet (fish-oil-free control diet), C diet (control group, assuming a Japanese diet), SDA25 diet (25% 18:4n?3 soybean oil in the C diet), SDA50 (50% 18:4n?3 soybean oil in the C diet), ALA diet (34% flaxseed oil in the C diet), and EPA+DHA diet (34% fish oil in the C diet). The intake of 18:4n?3 showed increased relative efficiency of 20:5n?3 accretions in serum and liver triacylglycerol and significantly decreased the serum triacylglycerol level in rats. The results suggested that the consumption of 18:4n?3 soybean oil may modify the lipid and fatty acid profiles of body fats, even when EPA and DHA derived from fish is consumed.     

Spectral quality during pod development affects omega-6 desaturase activity in soybean seed endoplasmic reticulum

Polyunsaturated fatty acids (i.e. linoleic acid [18:2], linolenic acid [18:3]) in triacylglycerols (TAG) of soybean seeds increase more during reproductive development under simulated shadelight: i.e., light with reduced blue and/or increased far-red (Britz and Cavins 1993). Elevation of 18:2 and 18:3 is matched by corresponding reduction of oleic acid (18:1), consistent with observations that total seed oil remains constant. We therefore tested the hypothesis that spectral quality affects the activity of the omega-6 and/or omega-3 desaturases involved in TAG biosynthesis. Membranes were isolated from developing soybean cotyledons 24–31 days after flowering. Separate fractions, enriched for chloroplasts and endoplasmic reticulum (ER) respectively, were obtained by sucrose gradient centrifugation and incubated in an in vitro desaturase assay system containing ¹⁴C-18:1–CoA at room temperature. Omega-6 and omega-3 desaturase activity was calculated from the rate of formation of ¹⁴C-18:2 and ¹⁴C-18:3. Radioactive 18:2 and 18:3 were recovered only from phosphatidylcholine (PC) in both ER and chloroplast membranes, consistent with membrane-bound desaturases with specificity towards PC. The specific activity of omega-6 desaturase was high in ER membranes from seeds matured under light sources that promote a canopy shade response, but was reduced in membranes from seeds matured under lamps (high blue and low far-red emission) previously shown to reduce the level of 18:2 in seed oil by 50%. Chloroplast membranes possessed both omega-6 and omega-3 desaturases. Light appeared to have little or no effect on the activity of chloroplast desaturases.     

Omega-3 long-chain fatty acids strongly induce angiopoietin-like 4 in humans

Angiopoietin-like 4 (ANGPTL4) is a regulator of LPL activity. In this study we examined whether different fatty acids have a differential effect on plasma ANGPTL4 levels during hyperinsulinemia in healthy lean males. In 10 healthy lean males, 3 hyperinsulinemic euglycemic clamps were performed during concomitant 6 h intravenous infusion of soybean oil (Intralipid® rich in PUFA), olive oil (Clinoleic® rich in MUFA) and control saline. In 10 other healthy lean males, 2 hyperinsulinemic clamps were performed during infusion of a mixed lipid emulsion containing a mixture of fish oil (FO), medium-chain triglycerides (MCTs), and long-chain triglycerides (LCTs) (FO/MCT/LCT; SMOFlipid®) or saline. FFA levels of approximately 0.5 mmol/l were reached during each lipid infusion. Plasma ANGPTL4 decreased during hyperinsulinemia by 32% (18–52%) from baseline. This insulin-mediated decrease in ANGPTL4 concentrations was partially reduced during concomitant infusion of olive oil and completely blunted during concomitant infusion of soybean oil and FO/MCT/LCT. The reduction in insulin sensitivity was similar between all lipid infusions. In accordance, incubation of rat hepatoma cells with the polyunsaturated fatty acid C22:6 increased ANGPTL4 expression by 70-fold, compared with 27-fold by the polyunsaturated fatty acid C18:2, and 15-fold by the monounsaturated fatty acid C18:1. These results suggest that ANGPTL4 is strongly regulated by fatty acids in humans, and is also dependent on the type of fatty acid.     

Desert date (Balanites aegyptiaca) as an arid lands sustainable bioresource for biodiesel

The aim of this study was to assess the suitability of Desert date (Balanites aegyptiaca L. Delile) as an oil crop in arid lands for large-scale sustainable industrial biodiesel production. Characterization of the Desert date plant material showed that using proper cultivation practices with emphasis on low quality irrigation water trees can be extremely well developed in hyper-arid conditions of the Israeli Arava desert and yield oil-rich fruits. Best selected trees can yield date fruits up to 52 kg/trees. Desert date kernels oil content may reach up to 46.7% (based on dry weight). The oil is consisted on four major fatty acids: palmitic (16:0), stearic (18:0), oleic (18:1), and linoleic (18:2), constituting 98-100% of the total fatty acids in the oil of all tested genotypes. Linoleic acid was the most prevalent fatty acid, ranging from 31% to 51% of the fatty acids profile, very similar to soybean oil profile. In situ biodiesel production directly from oil-enriched powder was successfully developed. Yield efficiency for both conventional and in situ biodiesel production was about 90%. The qualities of the produced biodiesel well meet the international biodiesel standards. The present study clearly demonstrated Desert date as a model for the utilization of bioresources in the Israeli Arava desert and potentially other similar areas for cost-effective biodiesel production.     

Natural variation of GmFATA1B regulates seed oil content and composition in soybean

Soybean (Glycine max) produces seeds that are rich in unsaturated fatty acids and is an important oilseed crop worldwide. Seed oil content and composition largely determine the economic value of soybean. Due to natural genetic variation, seed oil content varies substantially across soybean cultivars. Although much progress has been made in elucidating the genetic trajectory underlying fatty acid metabolism and oil biosynthesis in plants, the causal genes for many quantitative trait loci (QTLs) regulating seed oil content in soybean remain to be revealed. In this study, we identified GmFATA1B as the gene underlying a QTL that regulates seed oil content and composition, as well as seed size in soybean. Nine extra amino acids in the conserved region of GmFATA1B impair its function as a fatty acyl–acyl carrier protein thioesterase, thereby affecting seed oil content and composition. Heterogeneously overexpressing the functional GmFATA1B allele in Arabidopsis thaliana increased both the total oil content and the oleic acid and linoleic acid contents of seeds. Our findings uncover a previously unknown locus underlying variation in seed oil content in soybean and lay the foundation for improving seed oil content and composition in soybean.     

Genetic possibilities for altering sunflower oil quality to obtain novel oils

The sunflower is one of the four most important oilseed crops in the world, and the nutritional quality of its edible oil ranks among the best vegetable oils in cultivation. Typically up to 90% of the fatty acids in conventional sunflower oil are unsaturated, namely oleic (C 18:1, 16%-19%) and linoleic (C 18:2, 68%-72%) fatty acids. Palmitic (C 16:0, 6%), stearic (C 18:0, 5%), and minor amounts of myristic (C 14:0), myristoleic (C 14:1), palmitoleic (C 16:1), arachidic (C 20:0), behenic (C 22:0), and other fatty acids account for the remaining 10%. Advances in modern genetics, most importantly induced mutations, have altered the fatty acid composition of sunflower oil to a significant extent. Treating sunflower seeds with gamma- and X-rays has produced mutants with 25%-30% palmitic acid. Sunflower seed treatment with X-rays has also resulted in mutants having 30% palmitoleic acid, while treatments with mutagenic sodium azide have produced seeds containing 35% stearic acid. The most important mutations have been obtained by treatment with dimethyl sulfate, which produced genotypes with more than 90% oleic acid. Mutants have also been obtained that have a high linoleic acid content (>80%) by treating seeds with X-rays and ethyl methanesulfonate. Of the vitamin E family of compounds, sunflower oil is known to predominantly contain alpha-tocopherol (>90%). Spontaneous mutations controlled by recessive genes have been discovered that significantly alter tocopherol forms and levels. The genes in question are tph(1) (50% alpha- and 50% beta-tocopherol), tph(2) (0%-5% alpha- and 95%-100% gamma-tocopherol), and tph(1)tph(2) (8%-40% alpha-, 0%-25% beta-, 25%-84% gamma-, and 8%-50% delta-tocopherol). The existence of (mutant) genes for increased levels of individual fatty acids and for different forms and levels of tocopherol enables the development of sunflower hybrids with different oil quality. The greatest progress has been made in developing high-oleic hybrids (>90% oleic acid). There has been considerable work done recently on the development of high-oleic hybrids with altered tocopherol levels, the oil of which will have 10-20 times greater oxidative stability than that of conventional sunflower oil. While sunflower breeders work on developing hybrids with altered oil quality, medical scientists in general and nutritionists in particular will determine the parameters for the use of these novel types of oil that can improve human nutrition and be used in the prevention of cardiovascular diseases.     

Dietary effects of bitter gourd oil on blood and liver lipids of rats.

Bitter gourd is widely used as an edible plant in Asia. In this study, we evaluated the effects of bitter gourd oil (BGO) on the blood and liver lipids of rats. Three groups of rats were given a basal diet (AIN-93G) containing 7% fat by weight. The dietary fat consisted of soybean oil (control), soybean oil + BGO (6.5:0.5, w/w; 0.5% BGO), or soybean oil + BGO (5:2, w/w; 2.0% BGO). This fat treatment gave 3.4 and 15.4% of cis(c)9,trans(t)11,t13-18:3 in the dietary fat of 0.5 and 2.0% BGO, respectively. Fatty acid analysis showed the occurrence of c9,t11-18:2 in the liver of rats fed BGO diets, whereas this conjugated linoleic acid (CLA) isomer was not detected in the liver of rats fed the control diet. Furthermore, dietary BGO decreased the concentration of 18:2n-6 and increased the concentration of 22:6n-3. The formation of the CLA isomer in the liver lipids of rats fed BGO diets could be explained by either of the following two metabolic pathways, namely, enzymatic biohydrogenation of c9,t11,t13-18:3 or enzymatic isomerization of c9,c12-18:2. The BGO diets had significantly reduced free cholesterol levels with a trend toward an increase in HDL cholesterol, but there was no significant change in the total cholesterol. The dietary BGO also affected the level of plasma hydroperoxides. A slight but significant increase in hydroperoxides was found in the rats fed 2.0% BGO. This may be attributed to the lower oxidative stability of c9,t11,t13-18:3 in BGO.