桑树EIN2基因的分离与表达

EIN2是植物体内乙烯信号转导的中心元件,负责将乙烯信号由内质网传递到细胞核中。本文通过检索桑树基因组数据,获得一个EIN2候选基因(MaEIN2),并进行生物信息学分析和表达分析。该MaEIN2全长5614 bp,由7个外显子和6个内含子组成,包含3921 bp的CDS,编码1036个氨基酸残基。MaEIN2在进化树中与草莓、桃树等双子叶植物的EIN2蛋白关系较近,与单子叶植物关系较远。MaEIN2在老叶和成熟果实中的表达量分别高于在幼叶和幼果中,且随果实发育呈逐渐上升趋势,MaEIN2可能与器官的成熟衰老有关。选用乙烯利、ABA和NaCl处理桑树种苗,乙烯利能够促进MaEIN2的表达,而ABA和NaCl抑制MaEIN2的表达。本文为深入研究MaEIN2基因的功能奠定了基础。     

芒果CHS基因的克隆及其表达分析

为了研究芒果CHS基因的功能及其在果实着色中的分子机理,以芒果果实的c DNA和DNA为模板,采用同源克隆的方法克隆得到了一个CHS基因,该基因的开放阅读框1 194 bp,编码397个氨基酸,等电点为6.03,分子重量为43.29 k Da。基因组扩增得到了1 315 bp的片段,通过序列比对发现该基因含有1个内含子,对其在幼嫩叶片和成熟叶片中的表达进行分析,发现该基因在不同时期的叶片中都有表达,在红色幼嫩的叶片中表达量较高,成熟叶片中表达较低,初步推断该基因可能的叶片中黄酮类物质合成有密切的关系。通过聚类分析发现该基因编码的蛋白与兜兰、白芨等的CHS蛋白序列亲缘关系较近,可以与白芨、问荆草、甘蓝等聚为一类。     

粉蕉MbACS7基因的克隆及表达分析

乙烯合成及其效应是决定香蕉果实成熟的核心要素,其中1-氨基环丙烷-1-羧酸(ACC)合成酶(ACS)是乙烯合成途径的限速酶。粉蕉果实成熟速度较快,保鲜难度较大。研究粉蕉ACS家族基因的特征和表达模式可为控制香蕉果实成熟进程和延长货架期提供理论依据。本研究从粉蕉中克隆获得一个全长序列为1 458 bp的目的片段,编码485个氨基酸,分子量为54.751 kD,具有PLN02450保守结构域(37～1 377氨基酸),属于ACS基因家族蛋白,因此被命名为MbACS7。理化性质分析表明MbACS7蛋白亲水且不稳定。进化分析表明MbACS7蛋白预测的氨基酸序列与苦瓜(Momordica charantia) ACS蛋白的氨基酸序列(CAE53271.1)遗传关系较近。瞬时表达分析表明MbACS7蛋白在烟草表皮细胞的细胞核中强烈表达,表明该蛋白可能在细胞核中发挥着重要的生理功能。实时荧光定量表达分析表明MbACS7基因在粉蕉果实成熟期表达量最高,为果实发育初期的900多倍。本研究为进一步解析MbACS7基因在粉蕉果实乙烯生物合成中的功能奠定基础,也为改良香蕉果实贮藏性提供基因资源。     

香蕉MaEIL4的分离鉴定及其在果实采后成熟过程中的差异表达分析

为了明确香蕉果实中参与乙烯信号转导的关键基因,本研究在转录水平上对香蕉中的9个Ethylene insensitive 3-like (MaEIL)基因在果实采后成熟过程中的差异表达特性进行分析,找到关键基因并克隆其全长,采用生物信息学方法对其理化特性,结构特征,亚细胞定位进行分析,采用荧光实时定量PCR方法对其果实采后不同处理条件下的差异表达特性进行了深入研究。结果表明,MaEIL4在果实采后成熟过程中高水平表达。MaEIL4全长4 314 bp,单一外显子。其开放阅读框全长1 908 bp,编码635个氨基酸,分子式为C₃₁₀₄H₄₈₃₇N₈₈₃O₉₇₀S₃₄,分子量为71.13 kD,等电点为5.70,属于亲水性氨基酸。该基因具有典型的Ethylene insensitive 3 (EIN3)结构域。该基因编码蛋白质定位于细胞核中。MaEIL4在香蕉果实采后成熟过程中的表达明显受到外源乙烯的诱导,受1-MCP的抑制,表明MaEIL4参与了果实成熟早期乙烯信号的转导,在果实...     

黄灯笼辣椒多聚半乳糖醛酸酶基因CCaPG的生物信息学和表达分析

本研究根据Gene Bank已发表的辣椒基因组序列信息,设计引物,利用RT-PCR法从海南黄灯笼辣椒中克隆了多聚半乳糖醛酸酶基因(PG),并命名为CCa PG基因。生物信息学及表达分析结果表明,该基因CDS区全长1 107 bp,编码368个氨基酸,推测为稳定的亲水蛋白,在N端由一条长约25 aa的信号肽;CCa PG蛋白二级结构预测显示,α-螺旋占18.75%,延伸链占37.23%,无规则卷曲占36.41%,β-转角占7.61%。系统进化树分析结果显示,CCa PG与一年生辣椒的亲缘关系最近,达98.37%,其次为美花烟草76.16%。表达量分析发现,CCa PG基因在果实变色期表达量最高,其次为幼果期,最低为绿熟期。本结果可为研究该基因的生物学功能和黄灯笼辣椒果实软化的调控机制奠定理论基础。     

桃醛酮还原酶基因PrupeAKR2在果实成熟软化中的功能分析

PrupeSEP1在调节桃果实成熟软化过程中起重要作用,本研究通过PrupeSEP1酵母双杂筛库鉴定得到的互作蛋白PrupeAKR2。为了探究PrupeAKR2在桃果实成熟软化中的作用,本研究将PrupeAKR2在‘中桃5号’果实中瞬时过表达,研究其对果实贮藏期间质地指标,成熟软化相关基因的表达量变化的影响,同时利用酵母双杂交系统验证PrupeAKR2和PrupeSEP1是否存在互作。结果表明,瞬时过表达PrupeAKR2后,与对照(PC2300空载体)相比,果实加快软化。在采后贮藏的前2 d,OE-PrupeAKR2果实中成熟软化相关的PrupeACS1、PrupeACO1、PrupePME、PrupePG21、PrupePG22的表达均被抑制;而OE-PrupeAKR2果实在贮藏的4～10 d PrupeACO1和PrupePME的表达量、在贮藏的8～10 d PrupeACS1和PrupePG21的表达量、以及在贮藏的4～8 d PrupePG22的表达量均显著高于对照果实。酵母双杂交验证表明PrupeAKR2与PrupeSEP1存在互作关系。研究结果表明,桃PrupeAKR2和PrupeSEP1蛋白发生互作,且正向调控果实成熟软化。本研究可为PrupeAKR2调控果实成熟软化提供理论依据,对开展PrupeAKR2功能的深入研究具有重要意义。     

黄瓜ζ-胡萝卜素脱氢酶基因克隆及表达分析

以西双版纳黄瓜为试材,从黄瓜果肉中克隆ζ-胡萝卜素脱氢酶(ZDS)基因的cDNA序列,命名为CsZds。获得目的片段长度为1805bp,该序列具有完整的开放阅读框,位于31~1761bp,编码576个氨基酸。序列比对分析结果显示,该蛋白在氨基端变化十分明显,中部较为保守,存在一个特征序列。系统进化分析表明,推测的CsZDS蛋白与南瓜中ZDS蛋白同源性最高,达到91.84%。利用实时荧光定量PCR技术分析结果显示,随着果实成熟期的延长,西双版纳黄瓜CsZds基因的表达量呈明显上升的趋势,在转色期达到最大。在果实发育过程中,西双版纳黄瓜CsZds基因的表达量高于普通黄瓜。     

ClaMADS12基因克隆及在西瓜果实发育中的表达特性分析

本研究从西瓜果实发育转录组数据中,筛选出ClaMADS12基因,并对其进行基因克隆、生物信息学以及初步表达分析。生物信息学分析显示该基因的开放阅读框为3 374 bp,编码区全长621 bp,共编码206个氨基酸。结构域分析显示,该基因含有一个典型的“MADS-box”保守结构域,位于从N端第1到75个氨基酸,属于MADS-box家族。对其蛋白质的理化性质分析显示,ClaMADS12蛋白以异亮氨酸为主,无信号肽和跨膜结构域,属于不稳定型、亲水蛋白,亚细胞定位预测该蛋白位于细胞核。对该基因进行同源性比对及系统进化树分析显示,冬瓜MADS-box 12基因与ClaMADS12亲缘关系最近,同源性高达95.61%。RT-PCR分析表明,ClaMADS12在西瓜果实发育中,相对表达量与果肉质地的软化呈正相关。本研究为进一步明确ClaMADS12基因在西瓜果实发育中的功能提供依据。     

橄榄类黄酮3'-羟化酶CaF3'H基因的克隆及其表达特性分析

以‘清榄一号’橄榄(Canarium album)果肉为材料,通过RACE技术克隆得到橄榄类黄酮3'-羟化酶(F3'H)cDNA序列全长,命名为CaF3'H(GenBank登录号KY189088.1)。CaF3'H全长为1 649 bp,包含一个1 554 bp开放阅读框(ORF),编码517个氨基酸,5'和3'非编码区(UTR)长度分别为40 bp和55 bp,编码的氨基酸序列含有P450结构域和半胱氨酸亚铁血红素结合域保守区。氨基酸多重比较分析表明:橄榄和芒果的氨基酸序列相似性为78.89%,较之于其他物种相对最高。蛋白结构预测结果显示,CaF3'H蛋白呈弱亲水性,存在跨膜结构域,没有信号肽。实时荧光定量PCR分析显示,CaF3'H在‘清榄一号’和‘檀香’2个橄榄栽培品种的表达量在花后50 d达到最大值,此后其表达量随果实的成熟呈现出波动,总体表达量比花后50 d都低,这与橄榄生长发育时期多酚含量的变化趋势相符,推测CaF3'H基因在调控果实多酚含量过程中发挥着重要作用。     

橄榄果实氨基酸转运蛋白基因CaAAP1、CaAAP2和CaAAP4的克隆与表达分析

氨基酸通透酶(amino acid permease, AAP)参与植物氨基酸的转运、吸收、氮代谢等途径。为了解橄榄果实AAP基因在不同品种果实成熟发育过程的表达模式,本研究以呈味差异显著的两个品种普通橄榄‘长营’和清橄榄‘梅埔2号’为试验材料,通过RT-PCR方法克隆了3个APP基因的cDNA序列全长,并对其进行了生物学信息分析与亚细胞定位分析,同时利用实时荧光定量PCR技术分析了两个不同品种果实在不同发育时期的CaAAPs表达情况。结果表明：3个基因的序列长度分别为1 254 bp (CaAAP1)、405 bp (CaAAP2)、633 bp (CaAAP4),其编码的蛋白均为不稳定疏水性蛋白,分别含有7、1、5个跨膜区,保守基序差异较大;亚细胞定位结果表明,CaAAP1、CaAAP2主要在细胞质膜上表达。荧光定量结果表明随着果实的发育,CaAAP1、CaAAP2和CaAAP4在‘长营’果实的表达量均呈显著上升趋势,在‘梅埔2号’的表达量变化趋势较平缓,且在170 d时显著下降,两个品种CaAAPs家族基因表达量差异大,表明CaAAP1、CaAAP2、CaAAP4基因可能对橄榄果...     

Location of a high-lysine gene and the DDT-resistance gene on barley chromosome 7

Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans.     

Biological Activity and Quantification of Suspected Allelochemicals from Alfalfa Plant Parts

Autotoxicity restricts reseeding of alfalfa (Medicago sativa L.) after alfalfa until autotoxic chemical(s) breaks down or is dispersed into external environments. A series of aqueous extracts from leaves, stems, roots and seeds of alfalfa ‘Vernal’ were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. Extracts at 40 g dry tissue l^?1 from alfalfa leaves were 15.4, 17.5 and 28.7 times more toxic to alfalfa root growth than were those from roots, stems and seeds, respectively. A high‐performance liquid chromatography (HPLC) analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compounds depended on the plant parts. In leaf extracts that showed the most inhibitory effect on root growth, the highest amounts of allelochemicals were detected. Among nine phenolic compounds assayed for their phytotoxicity on root growth of alfalfa, coumarin, trans‐cinnamic acid and o‐coumaric acid at 10^?3 m were most inhibitory. The type and amount of causative allelochemicals found in alfalfa plant parts were highly correlated with the results of the bioassay, indicating that the autotoxic effects of alfalfa plant parts significantly differed.     

Simultaneous Determination of Four Phenolic Acids in Radix Salviae Miltiorrhizae Formula Granules by QAMS

[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol...     

Changes in Seed Yield and Quality with Maturity in Onion (Allium cepa L., cv. 'Early Cream Gold')

Development of onion (Allium cepa L., cv. ‘Early Cream Gold’) seed under cool climate conditions in Tasmania, Australia occurred over a longer duration than previously reported, but similar patterns of change in yield components were recorded. In contrast to previous studies, umbel moisture content declined from 85 to 67 % over 57 days while seed moisture content decreased from 85 to 31 %. Seed yield continued to increase over the duration of crop development, with increasing seed weight compensating for seed loss resulting from capsule dehiscence in the later stages of maturation. Germination percentage was high and did not vary significantly from 53 to 77 days after full bloom (DAF), but mean germination time declined and uniformity of germination increased significantly over the same time period. The percentage abnormal seedlings declined with later harvest date, resulting in highest seed quality at 77 DAF. The results of this study suggest that the decision to harvest cool climate onion seed crops before capsule dehiscence will result in a loss of potential seed yield and quality.     

Pollen and pollination experiments. III. The viability of apple and pear pollen as affected by irradiation and storage

Summary Apple and pear pollen was irradiated with doses of 0, 50, 100, 250 and 500 krad (gamma rays) and stored at 4°C and 0–10% r.h. From the in-vitro germination percentages an average LD 50 dose of about 220 krad was estimated. For both irradiated and untreated pollen a close and corresponding lineair relationship existed between germination percentage and pollen tube growth.Irradiated pollen was much more sensitive to dry storage conditions than untreated pollen, resulting in less germination and more bursting. Apparently, irradiation caused the pollen cell membrane to lose its flexibility faster than normal. Rehydration of dry-stored, irradiated pollen in water-saturated air restored germination percentages up to their initial levels. The importance of this procedure in germination trials is stressed.     

Evolution under domestication involving disturbance of genic balance

Summary An hypothesis is developed that the rapid change from wild plants into domesticated crops principally involves the selection of alleles with non-functional gene products which leads to reduced control of the highly integrated metabolism and morphogenesis previously accumulated by lengthy natural selection. Such disturbance of the genome produces altered physiological and morphological development which, although deleterious in nature, serves mankind better and has been selected.     

Genetic variation for disease and nematode resistances and forage quality in perennial diploid and tetraploid lucerne populations (Medicago sativa L.)

Summary Twenty-five lucerne populations of the Medicago sativa complex, which were either diploid or tetraploid and wild or cultivated, were analysed for their resistance to four different fungal diseases and to stem nematode. Forage quality, including stem digestibility and saponin content, was also tested.Populations varied in susceptibility to the diseases caused by Colletotrichum trifolii, Verticillium albo-atrum, Sclerotinia trifoliorum and Pseudopezizza medicaginis, and to the nematode Ditylenchus dipsaci. Except for Sclerotinia rot, sativa and falcata subspecies differed in susceptibility, but this grouping of populations did not account for the full range of variation among them. However, the resistance to P. medicaginis was much lower in the sativa than in the falcata populations.Populations also varied significantly in stem fiber content and digestibility. Stem digestibility was negatively correlated to forage yield. Wild sativa and falcata populations had lower fiber content and higher digestibility than cultivated sativa populations. The medicagenic acid was the sapogenin responsible for the anti-nutritional effect of the lucerne measured by the yellow mealworm larvae Tenebrio molitor. The medicagenic acid content was lowest for the pure sativa populations, highest for the pure falcata populations, and intermediate for the French sativa varieties that have some traits originating from falcata germplasm. Some populations could be used in breeding programs to improve disease and nematode resistance, and forage quality.     

Review of Effects of Active Components of Gastrodiae Rhizoma on Central Nervous System

In order to explore the pharmacological effects of active components of Gastrodiae Rhizoma on the central nervous system,through consulting related literatures,...     

Effects of Pb on Rhizosphere Soil Enzyme Activity and Chemical Constituents of Achyranthes bidentata Blume

[Objectives]The purpose of this study was to investigate the effects of Pb on rhizosphere soil enzyme activity and chemical constituents of Achyranthes bidentat...     

不同P-Zn配比对小麦幼苗微量元素营养的影响

采用了螯合-缓冲营养液培养方法对小麦进行了苗期培养试验,在3个P水平(0,0.6,3.0 mmol/L)和3个Zn水平(0,3,30 μmol/L)的完全组合下对小麦苗期生长及Zn、Fe、Cu、Mn营养进行了研究,旨在为小麦微肥施用提供理论依据.结果表明,P、Zn的正常供应促进了小麦生长,二者的缺乏与过量均会抑制小麦发育,且这种影响在冠部表现得更为明显.在小麦苗期,Zn与Cu的吸收存在明显的拮抗作用,但供Zn则促进了Zn和Cu的转运,而Mn转运则受到了抑制;过量供Zn时,大量Zn被转运到冠部,同时明显抑制了(Fe+Cu+Mn)的吸收总量;P的供应显著地抑制了Fe的吸收,但P的供应提高了Zn、Cu、Mn的转运率;P、Zn在对Zn与Fe、Cu、Mn间吸收竞争的影响中,Zn本身的影响要比P的影响更为明显,供Zn明显促进了小麦幼苗对Zn的吸收;在小麦幼苗冠部,Zn与Fe的竞争中,供P利于Zn的吸收,缺P则利于Fe的吸收;而Zn与Cu以及Zn与Mn间的竞争中,缺磷时利于Zn的吸收,供磷后则利于Cu和Mn的吸收.总之,小麦幼苗Zn、Fe、Cu、Mn营养中,P、Zn的不同配比会不同程度地改变Zn与Fe、Cu、Mn的协同或拮抗效应.