植物基因工程新途径：叶绿体转化

在植物基因工程研究中,叶绿体是继核转化之后又一新的遗传转化和表达受体,叶绿体转化体系具有可同时进行多基因转化,表达原核性,超量表达,后代遗传稳定,定点整合,不会产生基因沉默及母性遗传和安全性好等特点,本文着重介绍叶绿体转化体系的特点,国内外研究动态,存在的问题及未来发展方向。     

衣藻叶绿体遗传转化的研究

叶绿体遗传转人是近几年发展起来的新领域。本文主要介绍了叶绿体遗传转化的特点、基本原理和衣藻叶绿体遗传转化的方法与技术;     

Organellar Inheritance in Liverworts: An Example of Pellia borealis

Abstract Liverwort Pellia borealis is an allopolyploid species that originated after the hybridization and chromosome doubling of two cryptic species; Pellia epiphylla species N and Pellia epiphylla species S. A sequence comparison of chloroplast tRNAUCCGly, tRNAUUULys gene introns, the mitochondrial tRNAGCUSer gene intron, and the first intron of the coxIII gene in the case of three liverwort species studied revealed that the chloroplast and mitochondrial sequences are identical in P. borealis and P. epiphylla species N but different from homologous P. epiphylla species S sequences. Both mitochondria and chloroplasts of P. borealis were thus inherited from one parent—P. epiphylla species N. Studies on 14 different populations of P. borealis gave the same result. These are the first data on organellar transmission in liverworts, the earliest land plants. Moreover, we show that the intron sequences of some organellar genes, until now not used in any systematic studies, could be very good markers in studying taxonomic relationships in closely related species and reconstructing historical events.     

玄参科植物叶绿体基因组特征及系统发育分析

目的 探究玄参科（Scrophulariaceae）叶绿体基因组（chloroplast DNA, cpDNA）的特征及其系统发育关系。 方法 对湖北玄参进行DNA测序;通过组装与注释获得了其叶绿体基因组序列;并从GenBank下载46条玄参科植物叶绿体基因组序列进行比较分析。 结果 玄参科叶绿体基因组长度在142 336-154 710 bp;GC含量为37.7%-38.1%;展现出典型的四分体结构;其中大单拷贝区长度为83 531-97 103 bp;小单拷贝区为17 375-18 600 bp;反向重复区为13 497-25 695 bp。通过对玄参科叶绿体基因组成的比较;揭示了在进化过程中获得与丢失的模式。此外;共线性分析发现;玄参科叶绿体基因组排列较为保守;但也存在基因组重排事件。长重复序列分析结果显示;玄参科叶绿体基因组大多数是正向重复和回文重复;而简单重复序列分析则鉴定了117-156个SSR位点;其中以A/T组成的单核苷酸重复次数最多;占比高达85.50%-91.50%。通过相对同义密码子使用度（RSCU）分析;筛选出25个最优密码子;绝大部分以A/U结尾。分化时间分析表明;玄参科的共同祖先与近缘物种大约在70.5百万年前（MYA）分开;并在约52.4 MYA形成了一个单系分支;绝大多数玄参科物种出现在近50 MYA。 结论 玄参科叶绿体基因组虽具有相似的结构特征;但在其进化历程中;基因的获得与丢失以及基因组的重排现象亦有所发生。基于叶绿体基因组;构建了更为精细的玄参科系统发育树。此外;分化时间的研究表明;玄参科物种的快速分化主要发生在大约50百万年前。     

大粒香水稻叶绿体基因组特征分析

大粒香作为贵州重要的优质稻资源,推广种植面积大,并且在乡村振兴过程中为社会带来了较高的经济效益。然而,目前对大粒香基因组学的理论研究报道较少。为揭示大粒香水稻叶绿体基因组(cpDNA)特征及系统发育关系,该研究对大粒香叶绿体进行测序,并分析其基因组特征。结果表明:(1)大粒香水稻cpDNA全长134 563 bp,包括1个大单拷贝区(LSC,80 864 bp)、1个小单拷贝区(SSC,12 347 bp)和2个反向重复序列区(IR_s,20 676 bp)。(2)注释到129个基因,可分为蛋白编码、tRNA和rRNA三类基因,数量分别为85个、36个和8个。(3)密码子偏好分析显示,大粒香cpDNA密码子偏好A碱基或U(T)碱基,亮氨酸密码子使用了1 944次,使用次数最多; 半胱氨酸的密码子仅使用198次,使用次数最少。(4)检测到129个SSR,其中有95个单核苷酸重复且大部分SSR序列由A/T碱基组成。(5)系统发育分析结果显示,大粒香与热带粳稻亲缘关系最近,聚为一类。该研究结果揭示了大粒香叶绿体基因组信息,并确定了大粒香系统发育所属分支。     

鲜黄小檗叶绿体基因组特征及系统发育分析

【目的】为明确鲜黄小檗叶绿体基因组结构特征及其与同属类群的系统发育关系,对鲜黄小檗叶绿体基因组的结构特征进行解析和系统发育分析。【方法】用Illumina Hiseq X Ten技术测序,用CPGview、CodonW、MISA、Reputer、IRscope、mVISTA软件对鲜黄小檗叶绿体基因组特征进行分析,MEGA7软件中的ML法构建系统发育树。【结果】鲜黄小檗叶绿体基因组全长166 225 bp,呈典型的四分体结构,全基因组GC含量为38.07%;共注释得到144个基因,包括99个蛋白质编码基因、37个tRNA基因和8个rRNA基因,其中23个基因含有内含子,32个基因为双拷贝基因;偏好使用A/U结尾的密码子;共检测到98个SSR位点和150个散在重复序列,大部分SSR位点由A和T碱基组成;SSC和IR区的变异程度高于LSC区;系统发育分析发现鲜黄小檗与威宁小檗亲缘关系最近。【结论】鲜黄小檗叶绿体基因组特征与小檗属其他物种类似,为该属物种的分子鉴定、进化关系等提供了理论基础。     

叶绿体基因组在系统发育学及基因工程领域的应用

介绍了叶绿体基因组在系统发育学和基因工程这两个领域的应用研究进展：1)叶绿体基因组的DNA序列比较为植物系统发育学研究提供了可靠数据基础;2)叶绿体基因工程是高水平表达外源基因的重要途径之一,在生产医用蛋白、改良作物农艺性状和环境保护等方面有着广阔的应用前景。     

叶绿体基因工程简介

叶绿体是植物细胞中一种特殊的细胞器。自1988年开始,人们认识到叶绿体在植物基因工程中的特殊地位。叶绿体基因工程的特点,特别是其高效表达和安全性,使其受到越来越多的重视,本文对叶绿体转化作了较为全面的介绍,包括其优势、方法、用途及不足等内容。Abstract:Chloroplast is a kind of special cell organin plant cells.Since 1988,Scientists have realized its advantages in plant gene enginearing.It′s high efficient expression and safety made it been attached more and more importance to.This paper introduces the chloroplast transfer mation,including its advantages,methods,uses and defects.     

The complete chloroplast and mitochondrial DNA sequence of Ostreococcus tauri: organelle genomes of the smallest eukaryote are examples of compaction

The complete nucleotide sequence of the mt (mitochondrial) and cp (chloroplast) genomes of the unicellular green alga Ostreococcus tauri has been determined. The mt genome assembles as a circle of 44,237 bp and contains 65 genes. With an overall average length of only 42 bp for the intergenic regions, this is the most gene-dense mt genome of all Chlorophyta. Furthermore, it is characterized by a unique segmental duplication, encompassing 22 genes and covering 44% of the genome. Such a duplication has not been observed before in green algae, although it is also present in the mt genomes of higher plants. The quadripartite cp genome forms a circle of 71,666 bp, containing 86 genes divided over a larger and a smaller single-copy region, separated by 2 inverted repeat sequences. Based on genome size and number of genes, the Ostreococcus cp genome is the smallest known among the green algae. Phylogenetic analyses based on a concatenated alignment of cp, mt, and nuclear genes confirm the position of O. tauri within the Prasinophyceae, an early branch of the Chlorophyta.     

Transformation of nuclear and plastomic plant genomes by biolistic particle bombardment

Microprojectile bombardment is a powerful method for the transformation of various organisms and tissues. For plants, the biolistic approach is primarily used for transformation of cereals and other monocotyledons, as well as for dicotyledonous plants shown to be recalcitrant to Agrobacterium-based transformation of organellar genomes, and transformation of plant and algal chloroplasts has recently been reported. In this protocol paper we provide methods for nuclear and plastomic transformation of plants using the biolistic technique.     

Major lineages within Apiaceae subfamily Apioideae: a comparison of chloroplast restriction site and DNA sequence data

Traditional sources of taxonomic characters in the large and taxonomically complex subfamily Apioideae (Apiaceae) have been confounding and no classification system of the subfamily has been widely accepted. A restriction site analysis of the chloroplast genome from 78 representatives of Apioideae and related groups provided a data matrix of 990 variable characters (750 of which were potentially parsimony-informative). A comparison of these data to that of three recent DNA sequencing studies of Apioideae (based on ITS, rpoCl intron, and matK sequences) shows that the restriction site analysis provides 2.6–3.6 times more variable characters for a comparable group of taxa. Moreover, levels of divergence appear to be well suited to studies at the subfamilial and tribal levels of Apiaceae. Cladistic and phenetic analyses of the restriction site data yielded trees that are visually congruent to those derived from the other recent molecular studies. On the basis of these comparisons, six lineages and one paraphyletic grade are provisionally recognized as informal groups. These groups can serve as the starting point for future, more intensive studies of the subfamily.     

茜草叶绿体全基因组序列及其系统发育分析

以茜草科(Rubiaceae)植物茜草(Rubia cordifolia L.)为研究对象,采用Illumination高通量测序技术对其叶绿体全基因组进行测序,并运用MAGA11等生信学工具进行全基因组解析及系统发育分析。结果表明,(1)茜草叶绿体基因组呈典型的四分环状结构,总GC含量37.2%,长153 959 bp,其中包含大单拷贝(LSC)区83 844 bp、小单拷贝(SSC)区17 083 bp和2个反向重复(IR)区26 516 bp;共注释得到124个基因,包括79个蛋白质编码基因、37个tRNA和8个rRNA。(2)序列共鉴定到169个SSR位点,以A、T组成为主,包括129个单核苷酸、18个双核苷酸、11个三核苷酸、9个四核苷酸和2个五核苷酸,六核苷酸SSR未检测到;边界分析显示,茜草叶绿体基因组LSC区差异性最大,变异程度最高,而IRa区则差异性最小,最为保守。(3)最大似然法(ML)构建系统发育树显示,样品茜草与同属植物Rubia horrida以100%支持率聚为一类,茜草亚科、仙丹花亚科与金鸡纳亚科聚为姐妹类群,证明茜草科植物在进化过程中保守发育。