首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 486 毫秒
1.
长缘厚朴中的新配糖体   总被引:1,自引:1,他引:0  
从长缘厚朴(Magnolia rostrata W.W.Smith)干燥树皮的乙醇提取物中分离得到一个新的配糖体,1,1'-联苯-6',8',9'-三羟基-3-丙基-4-O-β-D吡喃葡萄糖苷(1),以及6个已知的苯丙素类配糖体,3,4-二羟基-烯丙基-3-O-α-L-吡喃鼠李糖(1→6)β-D-吡喃葡萄糖苷(2),3,4-二羟基-烯丙基苯-3-O-α-L-吡鼠李糖(1→2)β-D-吡喃葡萄糖苷(3),sinapaldehyde(E)-O-β-D-glucopyranoside(4),syringaresinol-di-O-β-D-glucopynanoside(5),A阿克苷(E)(6),IcarisideE5(7),经光谱和化学方法鉴定其结构。  相似文献   

2.
1993-1995年在山西省历山自然保护区对松鸦(Garrulusglandarius)的繁殖生态进行了观察。本区位平山西省中条山东段,地处翼城、沁水、阳城、垣曲四县交界,东经111°51'-112°36',北纬35°16'-35°37',面积24800hm2。主峰历山(舜王坪)海拔2321m。1工作方法根据松鸦的生活习性、垂直分布,选定了有代表性的4个调查样区。(l)大河样区:海拔1000-1500m。为针阔混交林,主要林木由油松、白皮松、杨、烨、辽东标等种类组成;灌丛有荆条、沙棘、黄刺玫、绣线菊等。沟谷深切,调查样区自刘家渠至兜垛。(2)猪尾沟样区:海拔1650一回80…  相似文献   

3.
飞机草中的化学成分   总被引:16,自引:0,他引:16  
从飞机草(Eupatorium odoratum Linn)中分离得7个化合物,经光谱分析鉴定为:山萘酚-4'-甲基醚(1),槲皮黄素7,4'-二甲基醚(2),刺槐素(3),柑桔素-4'-甲基醚(4),豆甾醇(5),β-谷甾醇(6)及β-胡萝卜甙(7)。  相似文献   

4.
通过PR-PCR方法,设计两对引物,克隆了黄瓜花叶病毒香蕉株系(CMV-Xb)RNA3,并进行了核苷酸和蛋白质水平上的分析,结果表明Xb株系RNA3全长2205nt,具有两个蛋白编码阅读框型架(ORF),其中5'端(97-936nt)编码一个279aa的3a蛋白;3'端(1225-1871nt)编码一个2188aa的CP蛋白。5'非编码域为96nt;其因间隔区(IR)长288nt;3'NR含有324nt。通过与亚组Ⅱ其它株系RNA3核苷酸和所编码产物推导的氨基酸序列分析发现,亚组Ⅱ株系无论在编码区还是非编码区的核苷酸同源性都相对较高;亚组Ⅱ株系在进化过程中具有连续性。  相似文献   

5.
马蹄莲的组织培养   总被引:7,自引:0,他引:7  
TissueCultureofZantedescltiaaethiopicaQILIWang,HANSu-Ying,YANGYun-Long,ZANGMeng-Yi,ZHANGJing-Tao(fort7wizlofmp,sleZlirzA叶如仪份功U——ndg,了~卯03080至)1植物名称马蹄莲de川b如旧办班规彻仲山)。2材料类别球茎。3培养条件基本培养基为改良MS(其中:NH4NO。,KNO3减半,加KH。PO;25mg/L,生根的MS全量)。附加物(mg/L):()6-BA2+NAA005+IBA0.05+LH50+Vc5;(2)6-BA0.75+NAA0.2+IBA02+LH50+Vc5;(3)6BA3+NAA0.2+LH80+Vc40;(4)6.BAI.5+NAA0…  相似文献   

6.
中药金樱子的化学成分   总被引:21,自引:0,他引:21  
从中药金樱子(Rosa laevigata Michx.)的果实是分离到7个化合物,经理化性质和波谱分析分别确定为β-谷甾醇(1)、胡萝卜甙(2)、乌苏酸(3)、2α,3β,19α,23-四羟基乌苏-12-烯-28酸(4),2α,3β,19α,23-四羟基乌苏-12-烯-28酸28-O-β-D-吡喃葡萄糖苷(5),2α,3β,19α,23-三羟基乌苏-12-烯-28酸(6)和4',5,7-三羟黄酮醇-3-O-β-D-(6”-O-(E)-p-羟基苯丙烯酰)吡喃葡萄糖苷(7),其中化合物4、5、7为首次从金樱子果实中分离得到。  相似文献   

7.
何首乌中新的二苯乙烯甙   总被引:8,自引:0,他引:8  
用反相层析法从何首乌(Polygonum multiflorum Thunb.)根茎的水提物只发得2个新的二苯乙烯甙(1,2)及9个已知化合物:没食子酸(3),2,6-二羟基-苯甲酸(4),吲哚-3-(L-)α氨基-α-羟基-丙酸)甲酯(5)1,2-二羟基丙烷-1-(4-羟基-苯基)(6),大黄素(7),大黄素-8-β-D-葡萄糖甙(8),(+)-lyoniresinol-3α-O-β-D-葡萄糖甙(9),2,3,4、,5-四羟基反式二苯乙烯-2-O-β-D-吡喃葡萄糖甙(10)和2,3,4',5-四羟基反式二苯乙烯-2,3,-二-O-β-D-吡喃葡萄糖甙(11)。亲化合物结构通过理化性质与波谱分析特别是2D NMR得以确定。化合物2表现出很强的DNA裂解活性,化合物1,2与10具有很强的抗脂质过氧化活性。  相似文献   

8.
TGF—β与细胞周期调节   总被引:6,自引:0,他引:6  
孙红  姚鑫 《生命科学》1998,10(2):80-86
作为一类重要的生长负调节因子;TGF-β能够抑制多种类型细胞的生长,并将其阻断在GI期。TGF-β对细胞周期的调节作用是通过:(1)下调细胞周期驱动器如cyclin、cdk等的表达水平;(2)降低G1期cyclin/cdk复合物的活性;(3)调节p27、p21和p15等cdk抑制因子的表达及活性等。此外,一些原癌基因和肿瘤抑制基因的产物如c-myc、RB等也在这一过程中起着重要作用。  相似文献   

9.
菝葜属13个种的染色体数目   总被引:1,自引:0,他引:1  
获英属(Silmax)常常放在广义的百合科(Liliaceaes.1.),是一个多为木本、攀援的(少为草本、直立)雌雄异株属"'。近几十年来人们根据它的某些独特性状已单立1科:获葵科(Smilaeaceae),一般含茨基属、肖获卖属(Heterosmilax)和RIPogonum等3个属'·'。本研究旨在以  相似文献   

10.
对节白蜡的组织培养及植株再生   总被引:12,自引:2,他引:10  
1植物名称对节白蜡(Fnainushupehen-sis),又名湖北白蜡,湖北俗称对节树、望乡树。2材料类别幼嫩茎段,取自本校盆景园20~30年生中型盆景桩(高50~60cm)当年新梢。3培养条件分化培养基:(1)MS+6-BA2.5mg·L-1(单位下同);(2)MS+6-BA5.0;(3)MS+6BA10.0;(4)WPM+6-BA2.5;(5)WPM+6-BA5.0;(6)WPM-6-BA10.0;(7)DKW+6-BA2.5;(8)DKW+6-BA5.0;(9)DKW+6-BA10.0。生根培养基:(1)WPM+IBA0.5;(11)WPM+IBA2.0。以上培养基均附加蔗糖30g·L-1,琼脂6g·L-1…  相似文献   

11.
A cDNA clone of the glycosylphosphatidylinositol (GPI)-anchored purple acid phosphatase (PAP) has been obtained by a combination of cDNA library screening and 5' rapid amplification of cDNA ends from Spirodela oligorrhiza plants grown under phosphate-deficient (−P) conditions. The open reading frame of the S. oligorrhiza PAP cDNA consists of 1 365 bp encoding a 455 amino acid protein. Its deduced amino acid sequence shows 82 and 80% similarity to Arabidopsis thaliana and Phaseolus vulgaris PAP, respectively. The amino acid residue, Ala439, followed by two more small amino acid residues, Asp and Ser, is predicted to be the GPI-anchoring ( ω ) site. The absence of a dibasic motif upstream of the putative ω site suggests that the PAP is a cell wall protein. This presumption is supported by the finding that PAP was released by digestion of the cell wall fraction with cellulase. The GPI anchor is speculated to be a signal for transporting PAP to the cell wall. Immunohistochemical results using −P plant roots demonstrate that PAP is preferentially distributed in the outermost cortical cells of roots but not in the epidermis, suggesting its role in acquiring inorganic phosphate under phosphate-deficient conditions. Northern blot analysis using the S. oligorrhiza PAP cDNA as a probe demonstrates that expression of the PAP gene increased during growth of −P plants and this time-dependent occurrence in mRNA levels of the PAP in −P plants was also observed in their protein and activity levels.  相似文献   

12.
13.
Antibodies are important for the study of pokeweed antiviral protein (PAP), an important antiviral agent against many plant, animal and human viruses. As PAP is expressed only at a low level in pokeweed plants (Phytolacca americana L.), it is complex and time‐consuming to extract PAP from pokeweed plants for antibody preparation. Here, we describe an antigen‐designed method according to the amino acid sequence that translated from PAP gene cleaving the C‐terminus toxic region and N‐terminus signal peptide (Genbank No. AF338910 ); the two peptides, DC15: DISGTERQDVETTLC and CR15: CRYPTLESKAGVKSR, were synthesized for generation of antibodies. The design strategy enabled straightforward antigen production and antibody generation. The antibodies can be used to detect PAP in transgenic petunia plants (Petunia hybrida Vilm.), pokeweed plants (P. americana) and transformed yeast (Pachia pastoris), which can express the PAP gene by western blotting. These antibodies generated against synthetic peptides will be useful for various assays such as for PAP detection, immunoprecipitation, protein purification and western blot analysis.  相似文献   

14.
The amino acid sequences of the large polypeptides of thiamin-binding proteins (TBPs) from sesame ( Sesamum indicum L.) seeds (STBP-I, -II and -III) were analyzed. The large polypeptides of STBP-I, -II and -III had the same amino acid sequences as did their small polypeptides. The peptide sequence information obtained from STBPs was used to synthesize DNA primers for amplification of the gene(s) encoding STBPs. A 200-bp fragment was amplified from cDNA synthesized from RNA from sesame seeds 4 weeks after flowering. The 200-bp fragment was used to clone full-length cDNA(s) encoding STBP(s) with RACE techniques. A 644-bp fragment was amplified, cloned and sequenced. The cDNA was a full-length clone encoding STBP(s). It contained an open reading frame, which defined a 143-residue polypeptide. The identified small and large polypeptide sequences of STBPs exactly matched the sequence encoded within the cDNA clone. These results indicated that the small and large polypeptides of STBPs were encoded on the mRNA as a single large proprotein precursor and that the final mature forms were generated by post-translational processing in the same manner as the other 2S albumins of plant seeds.  相似文献   

15.
Ribosome‐inactivating proteins (RIPs) are a class of plant defense proteins with N‐glycosidase activity (EC 3.2.2.22). Pokeweed antiviral protein (PAP) is a Type I RIP isolated from the pokeweed plant, Phytolacca americana, thought to confer broad‐spectrum virus resistance in this plant. Through a combination of standard molecular techniques and RNA sequencing analysis, we report here that a small RNA binds and cleaves the open reading frame of PAP mRNA. Additionally, sRNA targeting of PAP is dependent on jasmonic acid (JA), a plant hormone important for defense against pathogen infection and herbivory. Levels of small RNA increased with JA treatment, as did levels of PAP mRNA and protein, suggesting that the small RNA functions to moderate the expression of PAP in response to this hormone. The association between JA and PAP expression, mediated by sRNA299, situates PAP within a signaling pathway initiated by biotic stress. The consensus sequence of sRNA299 was obtained through bioinformatic analysis of pokeweed small RNA sequencing. To our knowledge, this is the first account of a sRNA targeting a RIP gene.  相似文献   

16.
H Tai  J G Jaworski 《Plant physiology》1993,103(4):1361-1367
A cDNA clone encoding spinach (Spinacia oleracea) 3-ketoacyl-acyl carrier protein synthase III (KAS III), which catalyzes the initial condensing reaction in fatty acid biosynthesis, was isolated. Based on the amino acid sequence of tryptic digests of purified spinach KAS III, degenerate polymerase chain reaction (PCR) primers were designed and used to amplify a 612-bp fragment from first-strand cDNA of spinach leaf RNA. A root cDNA library was probed with the PCR fragment, and a 1920-bp clone was isolated. Its deduced amino acid sequence matched the sequences of the tryptic digests obtained from the purified KAS III. Northern analysis confirmed that it was expressed in both leaf and root. The clone contained a 1218-bp open reading frame coding for 405 amino acids. The identity of the clone was confirmed by expression in Escherichia coli BL 21 as a glutathione S-transferase fusion protein. The deduced amino acid sequence was 48 and 45% identical with the putative KAS III of Porphyra umbilicalis and KAS III of E. coli, respectively. It also had a strong local homology to the plant chalcone synthases but had little homology with other KAS isoforms from plants, bacteria, or animals.  相似文献   

17.
Pokeweed antiviral protein II (PAPII), a 30 kDa protein isolated from leaves of Phytolacca americana, inhibits translation by catalytically removing a specific adenine residue from the large rRNA of the 60S subunit of eukaryotic ribosomes. The protein sequence of PAPII shows only 41% identity to PAP and PAP-S, two other antiviral proteins isolated from pokeweed. We isolated a cDNA corresponding to PAPII and introduced it into tobacco plants. PAPII expressed in transgenic tobacco was correctly processed to the mature form as in pokeweed and accumulated to at least 10-fold higher levels than wild-type PAP. We had previously observed a significant decrease in transformation frequency with PAP and recovered only two transgenic lines expressing 1–2 ng per mg protein. In contrast, eight different transgenic lines expressing up to 250 ng/mg PAPII were recovered, indicating that PAPII is less toxic than PAP. Two symptomless transgenic lines expressing PAPII were resistant to tobacco mosaic virus, potato virus X and the fungal pathogen Rhizoctonia solani. The level of viral and fungal resistance observed correlated well with the amount of PAPII protein accumulated. Pathogenesis-related protein PR1 was constitutively expressed in transgenic lines expressing PAPII. Although PR1 was constitutively expressed, no increase in salicylic acid levels was detected, indicating that PAPII may elicit a salicylic acid-independent signal transduction pathway.  相似文献   

18.
Depurination of plant ribosomes by pokeweed antiviral protein   总被引:4,自引:0,他引:4  
B E Taylor  J D Irvin 《FEBS letters》1990,273(1-2):144-146
Mammalian ribosomes have been shown to be enzymatically modified by ribosomal inactivating protein (RIPs) via specific depurination of rRNA. Here we report that ribosomes isolated from wheat germ contain intact and undepurinated rRNA and are depurinated by pokeweed antiviral protein (PAP). Pokeweed ribosomes isolated under the same conditions are depurinated. Total RNA isolated from pokeweed in the presence of strong denaturants was found to pbe partially depurinated. We conclude that wheat germ ribosomes are resistant to the endogenous RIP, tritin, but are sensitive to PAP and that pokeweed ribosomes can be depurinated by the N-glycosidase activity of endogenous PAP during isolation.  相似文献   

19.
A fragment of a complementary DNA (cDNA) clone for human prostatic acid phosphatase (PAP) (EC 3.1.3.2.) was used to study the expression of corresponding mRNA in human tissues. The specificity of its expression in benign prostatic hyperplasia (BPH) and prostatic carcinoma tissues were indicated in RNA blot analyses. The PAPcDNA probe did not recognize any specific mRNAs in RNAs extracted from human liver cancer, lung cancer, pancreatic cancer, placenta, breast cancer cells (MCF-7), mononuclear blood cells or acute promyelocytic leukemia cells (HL-60), according to Northern blot analysis. mRNA for PAP was detected in the androgen-dependent human prostatic cancer cell line LNCaP, but not in the androgen-insensitive human prostatic cancer cell line PC-3. In contrast, lysosomal acid phosphatase (LAP) mRNA was detected in both of these human prostatic cancer cell lines. Our findings indicate a high specificity for the PAP gene in prostatic tissue. The mean abundance for the PAPmRNA expression was 0.26 for prostatic carcinoma samples (n = 11) and 0.46 for BPH samples (n = 8) according to slot-blot analysis. The differences observed between the different categories of prostatic tissue in PAPmRNA abundances call for additional studies on regulation of its expression.  相似文献   

20.
砂梨脂氧合酶cDNA片段克隆与RNAi载体构建   总被引:4,自引:0,他引:4  
以砂梨‘若光’的成熟果实为材料,根据脂氧合酶氨基酸保守区设计1对简并引物,采用RT-PCR克隆到1段长827 bp的序列,经Blast比对和DNAstar软件聚类分析,结果表明由该序列推导出的氨基酸序列含有脂氧合酶氨基酸保守结构域,与马铃薯脂氧合酶基因的氨基酸序列相似性达到77.5%,判断其为砂梨脂氧合酶基因片段,命名为LOX1,并将序列登录到GenBank,登录号为EF215448。根据RNAi载体的构建原则,选择LOX1一开放阅读框设计携带酶切位点的特异引物,通过PCR扩增正、反向基因片段,再与YYT间隔区串连,插入植物表达载体pYF7713中的相应位置,成功地构建了干扰LOX基因表达的RNAi的植物双元表达载体pYL028,为深入研究该基因在砂梨果实成熟过程中的功能及耐贮藏基因工程育种奠定了基础。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号