大豆GmCOL8基因的克隆及表达分析

从大豆品种‘垦农18’中克隆了一个CONSTANS—like基因,命名为GmCOL8。进化树分析表明它属于CONSTANS—like亚家族1的成员。mRNA表达分析显示,GmCOL8在短日下具有明显的生物钟节律性表达特性,其表达高峰出现在凌晨。GmCOL8主要在复叶中表达,表达高峰出现在开花时期。     

Expression profiles of a CONSTANS homologue GmCOL11 in Glycine max

Soybean (Glycine max L.) is a typical short-day crop, and its flowering is strictly restricted by specific photoperiod conditions. CONSTANS (CO) plays a pivotal role in the photoperiod pathway of flowering regulation. CO-like genes are present in many plant species. Here we describe the isolation of the CO homologue GmCOL11 (Glycine max CO-like 11) from the soybean cv. Kennong 18. Sequence comparisons show that GmCOL11 is a group II CO-like gene with some similarity to AtCOL6 and AtCOL16. Its sequence includes a conserved B box and a CCT domain. The study of GmCOL11 expression using quantitative real time RT-PCR demonstrated that this gene was regulated in a diurnal rather than in a circadian manner. The gene was expressed throughout the plant, but mainly in adult leaves and maturing seeds; its expression was enhanced following flowering. Apparently GmCOL11 is involved in several aspects of soybean development.     

Molecular Analysis of Soybean Cultivars Differing in Response to Salinity Stress

Forty-seven soybean cultivars differing in response to sodium chloride were analyzed with 37 SSR markers for genetic diversity estimation. Thirty-two (86.5 %) out of 37 markers were polymorphic. The number of alleles ranged from 2–7 for different polymorphic markers, whereas the polymorphic information content (PIC) ranged from 0.061 to 0.793 with an average of 0.549. Average genetic similarity coefficient was 0.281. UPGMA based cluster analysis placed cultivars into five main clusters. In addition, the Mantel’s test for cophenetic correlation with r = 0.878 indicated good fit of the cultivars to a group in the cluster analysis. No clear pattern was observed between major clusters and place of release or targeted area of the cultivars. Genetically diverse cultivars were identified that could be potentially important sources of the germplasm for the development of salt tolerant cultivars in soybean.     

福建栽培大豆品种RAPD标记多样性分析

利用RAPD分子标记技术对福建18份栽培大豆品种遗传多样性进行研究.结果表明,12个引物共扩增出91条带,其中多态条带65条,多态性程度为71.43%.D=0.62时,聚类分析结果可以将供试材料分为3个大类群,即菜用大豆品种、杂交育成品种和地方品种、有半野生血缘的品种各聚成1类,揭示了福建省栽培大豆品种间的亲缘关系,同时还反映出品种间关系与地理起源有一定的相关.     

Identification and Expression Analysis of Cytokinin Metabolic Genes in Soybean under Normal and Drought Conditions in Relation to Cytokinin Levels

Cytokinins (CKs) mediate cellular responses to drought stress and targeted control of CK metabolism can be used to develop drought-tolerant plants. Aiming to manipulate CK levels to improve drought tolerance of soybean cultivars through genetic engineering of CK metabolic genes, we surveyed the soybean genome and identified 14 CK biosynthetic (isopentenyltransferase, GmIPT) and 17 CK degradative (CK dehydrogenase, GmCKX) genes. Comparative analyses of GmIPTs and GmCKXs with Arabidopsis counterparts revealed their similar architecture. The average numbers of abiotic stress-inducible cis-elements per promoter were 0.4 and 1.2 for GmIPT and GmCKX genes, respectively, suggesting that upregulation of GmCKXs, thereby reduction of CK levels, maybe the major events under abiotic stresses. Indeed, the expression of 12 GmCKX genes was upregulated by dehydration in R2 roots. Overall, the expressions of soybean CK metabolic genes in various tissues at various stages were highly responsive to drought. CK contents in various organs at the reproductive (R2) stage were also determined under well-watered and drought stress conditions. Although tRNA-type GmIPT genes were highly expressed in soybean, cis-zeatin and its derivatives were found at low concentrations. Moreover, reduction of total CK content in R2 leaves under drought was attributable to the decrease in dihydrozeatin levels, suggesting a role of this molecule in regulating soybean's responses to drought stress. Our systematic analysis of the GmIPT and GmCKX families has provided an insight into CK metabolism in soybean under drought stress and a solid foundation for in-depth characterization and future development of improved drought-tolerant soybean cultivars by manipulation of CK levels via biotechnological approach.     

Iron-stress Response in Mixed and Monocultures of Soybean Cultivars

Hawkeye (Fe-efficient) and PI-54619-5-1 (Fe-inefficient) soybeans (Glycine max [L.] Merr.) were grown in mixed and monoculture nutrient solutions to evaluate an inhibitory effect of PI-54619-5-1 on the uptake of Fe by Hawkeye. The ability of Hawkeye to take up Fe (Fe-stress response) was dependent on the degree of Fe stress (Fe deficiency) and was not the result of an inhibitory substance released by PI-54619-5-1 in mixed culture (Hawkeye + PI-54619-5-1).     

大豆基因家族的结构和表达分析

KNOX基因家族编码同源异型盒蛋白,在植物生长发育过程中起重要调控作用。利用生物信息学手段在全基因组水平上对大豆（Glycine Max）KNOX）（家族基因进行鉴定和分类,并分析其基因结构、蛋白同源结构域特征以及基因表达方式。研究结果表明：大豆中的27个GmKNOX基因可以分为GmKNOXl和GmKNOXll两个亚类,其中GmKNOXl类可分为3个主要的进化支,GmKNOXll类分为2个主要的进化支：26个GmKNOX基因不均匀地分布在16条染色体上,GmKNOX27尚无法定位。不同组织表达谱的分析表明：GmKNOXl类基因表达部位比较集中,以茎顶端分生组织中表达量最高：而GmKNOXll类基因的表达特异性较GmKNOXl类低,表达部位更广泛。     

大豆KNOX基因家族的结构和表达分析

KNOX基因家族编码同源异型盒蛋白, 在植物生长发育过程中起重要调控作用。利用生物信息学手段在全基因组水平上对大豆(Glycine max)KNOX家族基因进行鉴定和分类, 并分析其基因结构、蛋白同源结构域特征以及基因表达方式。研究结果表明: 大豆中的27个GmKNOX基因可以分为GmKNOX I和GmKNOX II两个亚类, 其中GmKNOX I类可分为3个主要的进化支, GmKNOX II类分为2个主要的进化支; 26个GmKNOX基因不均匀地分布在16条染色体上, GmKNOX27尚无法定位。不同组织表达谱的分析表明: GmKNOX I类基因表达部位比较集中, 以茎顶端分生组织中表达量最高; 而GmKNOX II类基因的表达特异性较GmKNOX I类低, 表达部位更广泛。     

Expression Stabilities of Candidate Reference Genes for RT-qPCR under Different Stress Conditions in Soybean

Due to its accuracy, sensitivity and high throughput, real time quantitative PCR (RT-qPCR) has been widely used in analysing gene expression. The quality of data from such analyses is affected by the quality of reference genes used. Expression stabilities for nine candidate reference genes widely used in soybean were evaluated under different stresses in this study. Our results showed that EF1A and ACT11 were the best under salinity stress, TUB4, TUA5 and EF1A were the best under drought stress, ACT11 and UKN2 were the best under dark treatment, and EF1B and UKN2 were the best under virus infection. EF1B and UKN2 were the top two genes which can be reliably used in all of the stress conditions assessed.     

Expression of Low Molecular Weight Heat-Shock Proteins under Field Conditions

Heat-shock proteins (HSPs) are known to be expressed in plants experiencing high-temperature stress. We have examined the expression of class I cytoplasmic low molecular weight (LMW) HSPs and find that these HSPs also frequently accumulate in seeds, seed pods, and flowers during a normal growing season. We first examined the expression of class I cytoplasmic LMW HSPs by western blot analysis in a range of seed samples from both commercially grown and wild legumes. LMW HSPs were present in all seed samples, indicating that these HSPs are regularly expressed in these tissues. To examine more specifically conditions under which LMW HSPs were produced during an average growing season, additional studies of Medicago sativa were carried out during the fall season in Tucson, AZ. Plants were irrigated to avoid conditions of water stress, and canopy temperature was monitored throughout the study period. LMW HSP expression in leaves, flowers, and developing seed pods was analyzed by western blotting. Results show that in the field HSPs are frequently produced in flowers and seed pods, even in plants that show no HSP expression in leaves. Parallel greenhouse studies indicate that HSP expression in seeds is in part developmentally regulated. In total our data suggest a more widespread occurrence of HSPs in optimal growth environments and emphasize their potential role during reproduction.     

SMV不同毒株在大豆植株内的病毒浓度比较

用SMV不同毒株接种大豆后,定期检测植株体内的病毒浓度。结果各毒株接种48小时后即在部分植株顶芽内洲出病毒,按种后20—25天植株内病毒含量最高。     

Galling and Yields of Soybean Cultivars Grown in Meloidogyne arenana-Infested Soil

Field trials with 39 soybean cultivars and five breeding lines from public and private sources were conducted from 1982 through 1985 at sites infested with Meloidogyne arenaria. Nematode population densities and root-knot galling were measured for each soybean entry. All were efficient hosts for the nematode, and average juvenile numbers in the soil increased 5-50 × from planting to harvest. Differences (P < 0.05) in galling were found among entries in each year. Centennial, Cobb, Coker 368, Hutton, and Jeff cultivars, recognized for their resistance to M. incognita, were severely galled and yielded poorly. Bedford, Forrest, A7372, Bragg, Braxton, Gordon, and Kirby, also recognized for their resistance to M. incognita, were among the least galled cultivars. Yields of all entries, however, were too low to justify their planting in sites heavily infested with M. arenaria.     

大豆微核心种质与育成品种的种子蛋白11S/7S比值的分析

大豆种子蛋白的11S/7S比值与大豆蛋白的营养品质和加工品质密切相关.本实验以205份微核心种质和248份育成品种为材料,利用SDS-PAGE电泳分离11S球蛋白和7S伴球蛋白的各亚基,通过Gel-pro analysis 4.5软件计算11S和7S的相对含量以及11S/7S比值.结果表明,参试品种的l1S和7S的含量呈极显著负相关(r=-0.32,p＜0.01),微核心种质和育成品种11S/7S比值范围分别为0.55～4.95和0.74～2.61,平均值均为1.56,变异系数分别为0.24%和0.19%.在参试材料中,没有检测到蛋白亚基缺失的材料,但在微核心种质与育成品种中筛选出β和A3亚基含量低的材料,其中,β低含量材料所占比例分别为9.3%和16.5%,A3低含量率分别为1.5%和0,说明微核心种质的11S/7S比值变异大于育成品种.通过比较发现,微核心种质中的南方大豆在所有参试大豆中11S/7S平均值最高,黄淮夏大豆在所有参试大豆中11S/7S平均值最低.研究结果表明,微核心种质比育成品种具有更丰富的遗传多样性,是鉴定优异资源的重要物质基础.     

大豆GmABI4基因克隆及表达分析

该研究基于大豆基因组数据库,根据拟南芥ABI4蛋白的氨基酸序列,经比对分析,获得了大豆中的2个GmABI4基因,分别命名为GmABI4-1(GenBank登录号为XM_014766551.1)和GmABI4-2(GenBank登录号为NM_001249003)。TMHMM软件和系统进化转录分析表明,这2个基因编码的蛋白均不具有信号肽,二级结构主要以无规则卷曲和延伸链为主;进化树分析表明,大豆GmABI4和野生大豆亲缘关系较近。荧光定量PCR分析表明,GmABI4-1与GmABI4-2基因在大豆种子与豆荚中的表达量均高于根、茎、叶、花等其他组织,推测可能与调控大豆种子生命活动相关。     

大豆ERF转录因子基因GmERF8的克隆与表达分析

ERF转录因子广泛存在于植物中并且参与植物应对生物及非生物胁迫的响应。本研究利用RT-PCR技术从大豆中克隆获得1个新的ERF转录因子基因Gm ERF8,开放阅读框全长627 bp,编码1个由208个氨基酸残基组成的分子量为23.43 k D的蛋白。蛋白结构预测发现,该蛋白含有1个典型的AP2/ERF结合域,2个预测的核定位信号和1个保守的EAR抑制元件。进化分析表明Gm ERF8蛋白与烟草Nt ERF3蛋白的同源性最高。实时荧光定量PCR表明,Gm ERF8在大豆的根和叶中表达量较高。ABA、高盐和低温处理均使Gm ERF8表达量下降;乙烯(ET)和干旱处理则使Gm ERF8的表达量先下降后升高。转录调节能力分析结果显示,Gm ERF8可以抑制报告基因的表达。上述实验结果表明,Gm ERF8可能作为转录抑制子参与大豆对环境胁迫的应答。     

河北省大豆推广品种遗传多样性分析

利用主要农艺性状以及SSR和AFLP2种分子标记,对河北省41个大豆推广品种进行遗传多样性分析,以便为种质资源利用和创新提供依据。农艺性状聚类结果将41个材料划分为3个类群和2个特殊品种,聚类结果与材料系谱来源相差悬殊,不能反映材料间亲缘关系。SSR和AFLP数据聚类结果将41个材料划分为4个SAG（SSR and AFLP—basedgroups）分子类群。30对SSR引物共检测出135个等位变异,平均每个位点上有4．47个等位变异,SSR的遗传多样性指数（Simpson）分布范围为0．0928～0．7800,平均值为0、6442。10对AFLP引物共扩增出93个多态性标记,平均每对引物9．3个多态性标记。品种间的遗传相似系数（GS）变化范围为0．5877～0．9868,平均值变化范围为0．6732～0．7653,总体平均值为0.7237,遗传相似系数较高,说明材料间遗传变异较小。     

Interaction of Four Soybean Cultivars with Subsoiling and a Nematicide

Yields of four soybean, Glycine max, cultivars were increased with subsoiling under the row and application of the nematicide, DBCP i 1,2-dibromo-3-chloropropane) in Tiflon sandy loam heavily infested with the root-knot nematode Meloidogyne incognita. These cultivars represent four maturity groups: very early (V), "Essex'', early (VI), "Davis'': medium (VII), ''Ransom''; and late (VIII), '' Hutton ''. The average increase for the four cullivars was about the same for subsoiling or DBCP. When the treatmcnts were used together, the increase was greater than when either was used alone, but the effects were not additive. Increased yields were obtained with subsoiling and DBCP for the most nematode resistant cultivar, Hutton, as well as for the most susccptiblc, Davis. Subsoiling reduced root-knot galling in nonfumigated plots but did not affect it in fumigated plots. On 12 September, M. incognita larvae were most numerous at the 0- to 20 cm depth, intermediate at 20 to 33 cm depth and least numerous at 33 to 46 cm depth, Subsoiling did not affect larval populations at the three levels.     

Comparison of Salt-Induced Osmotic Adjustment and Trigonelline Accumulation in Two Soybean Cultivars

21-d-old seedlings of the soybean (Glycine max) cvs. Essex and Forrest were treated with NaCl in a step-wise manner over 9 d (3 d 30 mM, 3 d 70 mM, and 3 d 100 mM) and maintained under 100 mM NaCl for an additional 14 d. During salt treatment, osmotic potential decreased more in cv. Forrest relative to cv. Essex. In non-stressed leaf tissue, cv. Forrest contained more trigonelline (TRG) relative to cv. Essex. During salt treatment, TRG amounts increased in cv. Forrest but were unchanged in cv. Essex. Both cvs. osmotically adjusted in response to salt stress; the maximal osmotic adjustment was 0.80 and 0.18 MPa in cv. Forrest and cv. Essex, respectively. This revised version was published online in June 2006 with corrections to the Cover Date.     

大豆GmOLPa基因的蛋白序列分析及原核表达

以盐诱导后的大豆根为材料,提取总RNA,RT-PCR得到GmOLPa目的片段。对其蛋白序列分析表明,该蛋白属于GH64-TLP-SF同源超家族中的PR-5蛋白,第25-244位氨基酸是其保守结构域,与番茄中的PR-5亲缘关系最为接近。构建GmOLPa基因ORF的原核表达载体pET-28-GP,并对其在大肠杆菌BL21中的表达条件进行优化。SDS-PAGE证实重组质粒能够在大肠杆菌BL21中表达,目的蛋白分子量约为30 kD,最佳诱导时间为4 h,最佳IPTG诱导浓度为1.0 mmol/L。