大豆幼苗期间不同器官中的葫芦巴碱含量变化

用高效液相色谱法测定大豆幼苗各器官中葫芦巴碱含量的结果表明：子叶期的子叶中葫芦巴碱含量高于根;对生真叶期间,葫芦巴碱含量大小依序为,真叶〉子叶〉根;三出复叶期间,葫芦巴碱含量大小依序为,三出复叶〉真叶〉子叶〉茎和根。     

盐胁迫对大豆种子萌发及矿质元素变化的影响

以大豆为试验材料,测定了中性盐和碱性盐胁迫下大豆种子的萌发、生长参数及各种矿质元素的含量,试图揭示盐胁迫下大豆种子萌发与矿质元素的响应过程及其相互关系。结果表明:大豆种子的萌发率、萌发势、萌发指数及生物量等在高浓度盐胁迫下均呈降低趋势,高浓度碱性盐胁迫比中性盐胁迫下降的趋势更为显著;盐胁迫下,大豆种子萌发过程中矿质元素含量与萌发参数存在显著相关关系。同时,盐胁迫下各种矿质元素在大豆子叶中呈逐渐降低、根中逐渐升高的趋势,造成了大豆体内矿质离子不平衡;尤其是高浓度碱性盐胁迫下,大豆根中矿质元素积累量更大,离子失衡更为显著。研究表明,盐胁迫尤其是高浓度碱性盐胁迫造成了大豆种子中矿质离子大幅度的失衡,对大豆种子的萌发和生长造成严重的伤害。     

不同苜蓿品种种子萌发期耐盐性的研究

用0．3％、0．7％和1．0％的Nacl溶液分别对19个苜蓿品种种子进行处理,通过发芽势、发芽率,幼根长和幼苗高对各品种种子萌发期耐盐性进行了研究。结果表明：用0．7％或1．0％NaCl溶液进行苜蓿种子萌发期耐盐性鉴定较为合理;0．7％NaCl溶液处理苜蓿种子,其幼根长及其幼苗高可作为苜蓿品种种子耐盐性鉴定的指标;在0．7％、1．0％NaCl溶液处理下,通过测定第4天和第6天各品种种子的发芽势,可以鉴定出苜蓿品种间耐盐力的大小。对19个苜蓿品种种子的发芽率、相对发芽势、幼根长和幼苗高4个耐盐鉴定指标进行综合分析,结果表明：超级13R和中苜1号种子耐盐性最强,其次为射手和牧野,全能 Z和牧歌401 Z最弱。     

经大豆DNA溶液处理的水稻后代种子的粗蛋白和氨基酸含量分析初报

以大豆为外源DNA供体,用浸种及幼苗期浇灌法和花粉管通道法直接将大豆总DNA导入受体水稻,经常规栽培获得水稻后代种子。采用微量凯氏定氮法和氨基酸自动分析仪进行水稻后代种子糙米的粗蛋白含量和氨基酸含量的测定。结果显示:三组经大豆DNA溶液处理获得的水稻后代种子糙米粗蛋白平均含量分别为16.42%、16.80%和19.87%,与对照组相比有明显提高,统计分析都达到极显著的差异(P < 0.01);在氨基酸含量测定中,有些材料的总氨基酸(除色氨酸以外)含量高达17.20%、16.86%和16.09%,其中赖氨酸的含量分别为0.60%、0.60%和0.57%,与对照组相比也有明显提高,统计分析差异也都达到极显著水平(P < 0.01)。本试验结果充分说明,利用大豆总DNA的导入方法有可能达到迅速有效地提高稻米蛋白质及赖氨酸含量的目的。     

经大豆DNA溶液处理的水稻后代种子的粗蛋白的氨基酸含量分？…

以大豆为外源ＤＮＡ供体,用浸种及幼苗期浇灌法和花粉管通道法直接将大豆总ＤＮＡ导入受体水稻,经常规栽培获得水稻后代种子。采用微量凯氏定氮法和氨基酸自动分析仪进行水稻后代种子糙米的粗蛋白含量和氨基酸含量的测定。结果显示：三组经大豆ＤＮＡ溶液处理获得的水稻后代种子糙米粗蛋白平均含量分别为１６．４２％、１６．８０％和１９．８７％,与对照组相比有明显提高,统计分析都达到极显的差异（Ｐ＜０．０１）;在氨基酸     

诱导紫云英根瘤菌nod基因表达的一些植物因子

利用柱层析,薄层层析和高压液相色谱从紫云英种子中分离并纯化对紫云英根瘤菌ｎｏｄ基因表达有诱导活性的成分,质谱鉴定为柚皮素。１９种类黄酮或非类黄酮化合物对此紫云英根瘤菌结瘤基因表达的诱导活性实验表明,紫云黄根瘤菌的结瘤基因可以应答多种诱导成分,除柚皮素外,还有类黄酮物质毛地黄黄酮,大豆素以及非类黄酮化合物７－羟基香豆素和葫芦巴碱。     

湖北省豆类植物种子硒含量的测定及赋存状态的研究

硒是人类必需的微量元素之一。我们对湖北省豆类植物种子的硒含量进行测定并对硒的赋存状态进行了研究。结果显示:大豆具有较强的富硒能力;大豆硒的赋存形态是含硒蛋白质,主要存在于白蛋白和球蛋白中;高硒地区的大豆含硒量比一般地区高近100倍。     

山西大豆皂苷类型及其关键酶基因表达分析

大豆皂苷Aa、Ab的含量影响大豆制品口感,旨在了解大豆籽粒中皂苷Aa和Ab的组成及含量,进而研究其合成代谢机制。采用HPLC-ESI-MS/MS技术测定大豆材料中Aa、Ab皂苷的含量,利用q RT-PCR技术研究籽粒发育过程中GmSg-1基因的相对表达量。结果显示,68个山西大豆材料种子中Aa型大豆材料胚和子叶中Aa皂苷含量的变异范围分别为0.41-33.79 mg/g,0.21-8.39 mg/g;Ab型大豆胚和子叶中Ab皂苷的变异范围分别为0.85-44.96 mg/g,0.26-11.09 mg/g。GmSg-1基因序列有19个SNP多态性位点,其中10个SNP引起氨基酸变异。Aa、Ab大豆皂苷含量在籽粒发育过程中呈现先增后减的趋势,在开花后40-50 d皂苷含量达到最大值,而GmSg-1基因的相对表达量在前期呈现与含量基本相同的趋势。     

南苜蓿、天蓝苜蓿、紫花苜蓿根茎叶中皂苷含量的测定和比较

采用比色法测定南苜蓿、天蓝苜蓿、紫花苜蓿根茎叶中的皂苷含量。以齐墩果酸为标准品,利用香草醛-冰醋酸体系,在545nm处检测,浓度在50μg/mL～150μg/mL范围内线性关系良好,其回归方程为Y=0.0073X-0.2178,相关系数R=0.9994。本法简便、快速、准确、可靠。实验结果表明,南苜蓿、天蓝苜蓿、紫花苜蓿三者中,根中皂苷含量大于茎中和叶中皂苷含量,紫花苜蓿根中皂苷含量略高于其他两种苜蓿;叶中皂苷含量与茎中皂苷含量无明显差异。     

大豆中皂甙的分布及其变化规律

通过测定大豆中皂甙的含量分布,结果为:胚芽(182～198%)>绿叶(072～084%)>全粒种子(031～036%)>豆节(030～034%)>子叶(024～030%)>侧根(019～021%)>豆荚(014～016%)>主根和豆茎(006～009%)>种皮(未检出);从品种上来看,全粒种子皂甙的含量是青刀豆(040～044%)>豇豆(037～040%)>赤豆(035～039%)>黄大豆(031～035%)>黑豆(023～028%)>绿豆(007～009%);同品种不同生长期的不同器官的皂甙含量呈现规律性的变化;不同区域的同品种大豆种子的皂甙含量存在着差异;不同播种期的各器官皂甙含量也存在差异。     

Isolation of eukaryotic ribosomal proteins. Purification and characterization of the 60 S ribosomal subunit proteins L4, L5, L7, L9, L11, L12, L13, L21, L22, L23, L26, L27, L30, L33, L35', L37, and L39.

The proteins of the large subunit of rat liver ribosomes were separated into seven groups by stepwise elution from carboxymethylcellulose with LiCl at pH 6.5. Seventeen proteins (L4, L5, L7, L9, L11, L12, L13, L21, L22, L23, L26, L27, L30, L33, L35', L37, and L39) were isolated from three of the groups (B60, D60, G60) by ion exchange chromatography on carboxymethylcellulose and by filtration through Sephadex. The amount of protein obtained varied from 0.5 to 15 mg. Eight of the proteins (L9, L11, L13, L21, L22, L35', L37 and L39) had no detectable contamination; the impurities in the others were no greater than 9%. The molecular weight of the proteins was estimated by polyacrylamide gel electrophoresis in sodium dodecyl sulfate; the amino acid composition was determined.     

The complete primary structure of ribosomal proteins L1, L14, L15, L23, L24 and L29 from Bacillus stearothermophilus

The amino acid sequences of ribosomal proteins L1, L14, L15, L23, L24 and L29 from Bacillus stearothermophilus have been completely determined. This has been achieved by sequence analyses of peptides derived from enzymatic digestions of the proteins with trypsin, chymotrypsin, pepsin, Staphylococcus aureus protease, and Armillaria mellea protease as well as by chemical cleavage with hydroxylamine and cyanogen bromide. Based on the primary structures of the six proteins, their secondary structures were predicted using four different computer prediction programs. A comparison of the amino acid sequences of the studied proteins from B. stearothermophilus with the homologous proteins from Escherichia coli revealed that in four proteins (L1, L15, L24 and L29) between 40-50% of the residue in the sequences are identical, whereas this value is significantly higher (69%) for L14 and lower (28%) for L23. The distribution of those amino acid residues which are identical in the corresponding proteins from the two bacteria is not random along the protein chain: some regions are highly conserved whereas others are not. This finding indicates that the regions which are conserved during evolution are important for the spatial structure and/or function of the protein.     

Sequence of the amino-terminal region of rat liver ribosomal proteins S4, S6, S8, L6, L7a,L18, L27, L30, L37, L37a,and L39

The sequence of the amino-terminal region of eleven rat liver ribosomal proteins–S4, S6, S8, L7a, L18, L27, L30, L37a, and L39 - was determined. The analysis confirmed the homogeneity of the proteins and suggests that they are unique, since no extensive common sequences were found. The N-terminal regions of the rat liver proteins were compared with amino acid sequences in Saccharomyces cerevisiae and in Escherichia coli ribosomal proteins. It seems likely that the proteins L37 from rat liver and Y55 from yeast ribosomes are homologous. It is possible that rat liver L7a or L37a or both are related to S cerevisiae Y44, although the similar sequences are at the amino-terminus of the rat liver proteins and in an internal region of Y44. A number of similarities in the sequences of rat liver and E coli ribosomal proteins have been found; however, it is not yet possible to say whether they connote a common ancestry.     

Localization of proteins L4, L5, L20 and L25 on the ribosomal surface by immuno-electron microscopy

Summary Ribosomal proteins L4, L5, L20 and L25 have been localized on the surface of the 50S ribosomal subunit of Escherichia coli by immuno-electron microscopy. The two 5S RNA binding proteins L5 and L25 were both located at the central protuberance extending towards its base, at the interface side of the 50S particle. L5 was localized on the side of the central protuberance that faces the L1 protuberance, whereas L25 was localized on the side that faces the L7/L12 stalk. Proteins L4 and L20 were both located at the back of the 50S subunit; L4 was located in the vicinity of proteins L23 and L29, and protein L20 was localized between proteins L17 and L10 and is thus located below the origin of the L7/L12 stalk.     

Structural comparison of the prokaryotic ribosomal proteins L7/L12 and L30

The structures of two prokaryotic ribosomal proteins, the carboxyterminal half of L7/L12 from Escherichia coli (L12CTF) and L30 from Bacilus stearothermophilus display a remarkably similar fold in which alpha-helices pack onto one side of an antiparallel, three-stranded, beta-pleated sheet. A detailed comparison of the structures by least-squares methods reveals that more than two-thirds of the alpha carbons can be superimposed with a root mean square distance of 2.33 A. The principal difference is an extra alpha-helix in L12CTF. The sequences of the proteins display a distinct conservation in regions which are crucial to the common fold, in particular the hydrophobic core. It is proposed that the similarity is a result of divergent evolution.     

Direct Organogenesis and Plant Regeneration in Preconditioned Tissue Cultures of Lathyrus cicera L., L. ochrus (L.)DC. and L. sativus L.

This study demonstrates the importance of preconditioning ofsource tissue in regeneration of multiple shoot buds from severalspecies of Lathyrus. Preconditioned multiple shoots of Lathyruscicera L., L. ochrus (L.) DC. and L. sativus L. were obtainedby germinating seeds on Murashige and Skoog (MS) medium containing50 µM N⁵-benzylaminopurine (BAP) for 2 to 3 weeks. Multipleshoot bud formation occurred when epicotyl explants of preconditionedshoots were cultured on MS medium containing 5–50 µMBAP. No shoot regeneration was observed from epicotyl explantswhich were obtained from non-preconditioned shoots. Shoot budswere formed directly on explants without an intervening callusphase after 2 to 3 weeks of culture. Regenerated shoot budsformed healthy shoots which developed prolific and strong rootswhen transferred to MS medium supplemented with 2.5 µMnaphthaleneacetic acid (NAA). Lathyrus cicera L., L. ochrus (L.) DC., Ochrus Vetch, L. sativus L., Lathyrus pea, de novo differentiation, epicotyl, preconditioning with BAP     

Structural alteration of rRNA in the L7/L12 region of 50s ribosome on removal of L7/L12 proteins

Core particles of 50S ribosomes depleted of $\text{L7}\text{L12}$ proteins are degraded by RNase I at a considerably slower rate than intact 50S ribosomes. The normal rate is restored on incorporating $\text{L7}\text{L12}$ proteins into the core particles. The capacity of the core particles to inhibit the RNase I-catalyzed hydrolysis of poly A and to bind ethidium bromide is also greater with core particles than with intact 50S ribosomes. It appears from these results that the region(s) of rRNA in the vicinity of $\text{L7}\text{L12}$ proteins has less ordered structure which, on removal of $\text{L7}\text{L12}$ proteins, becomes more organized. Apparently, binding of $\text{L7}\text{L12}$ proteins to the 50S core leads to the destabilization of double-stranded regions of rRNA.