Fertility Restoration Is Associated with Loss of a Portion of the Mitochondrial Genome in Cytoplasmic Male-Sterile Common Bean

Restoration of pollen fertility to cytoplasmic male-sterile common bean by nuclear gene Fr is accompanied by mitochondrial (mt) DNA rearrangements within restored plants. These rearrangements are also observed upon spontaneous cytoplasmic reversion to fertility. An mtDNA fragment of at least 25 kilobases was lost from the genome upon restoration or reversion. This fragment contained DNA segments that were not repeated elsewhere in the genome and, therefore, were not detected within the genome upon fertility restoration. This result suggested that the particular mtDNA configuration absent from restored plants could not be maintained by a constant process of recombination but rather by autonomous replication. No evidence of excision of this region from the mt genome, in the form of a junction fragment associating flanking DNA regions, was detected in fertile restored plants. DNA gel blot hybridization of this mtDNA region, compared with hybridization to related regions of the mitochondrial genome that shared sequence homology, indicated that the mtDNA region associated with sterility was present in lower copy number. These observations, as well as the occurrence of similar or identical rearrangements upon spontaneous cytoplasmic reversion, indicate that the restoration of pollen fertility may be accompanied by loss of an independently replicating subgenomic DNA molecule from the mitochondrial genome.     

Plant Mitochondrial Genome Evolution and Cytoplasmic Male Sterility

Mitochondria are responsible for providing energy currency to life processes in the molecular form of ATP and are therefore typically referred to as the power factories of cells. Plant mitochondria are also relevant to the common phenomenon of cytoplasmic male sterility, which is agronomically important in various crop species. Cytoplasmic male sterility (CMS) is a complex trait that may be influenced by patterns of mitochondrial genome evolution, and by intergenomic gene transfer among the organellar and nuclear compartments of plant cells. Here, we review patterns and processes that shape plant mitochondrial genomes, some relevant interactions between organelles, and the general features shared by the majority of cytoplasmic male-sterile genes in plants to further the goal of understanding CMS.     

水稻线粒体基因组翻译产物与细胞质雄性不育性

通过线粒体离体翻译产物的电泳和放射性自显影分析,发现水稻BT型不育细胞质(农虎26A和丰锦A不育系)的线粒体基因产物比可育细胞质(农虎26B和丰锦B保持系)缺少一个22KD多肽。它反应了BT型不育细胞质线粒体基因组中有关育性的基因变异。不育系与恢复系杂交后,杂种F_1的育性虽然恢复,但是它的线粒体基因产物中仍然缺少22KD多肽。然而,在杂种F_1的线粒体蛋白质的电泳染色图谱中则显示出一个22KD多肽条带。杂种F_1中的这个22KD多肽是核基因产物。它弥补了线粒体基因组中育性基因的缺陷。     

棉花'晋 A'细胞质雄性不育恢复基因定位

用晋A衍生不育系与恢复系组配的分离群体进行遗传与定位分析,晋A恢复基因在F2和BC1的分离比例分别符合3∶1和1∶1,证明恢复基因由1对显性基因控制.用9个SSR标记和4个STS标记构建长度为82.1 cM的连锁群,恢复基因Rf定位在第19染色体(D08),与最近的标记CM042和CIR179分别相距5.4 cM和10.3 cM.以晋A衍生的7个不育系、4个保持系和10个恢复系对标记进行验证,分别扩增出同样的特异带型,说明与晋A恢复基因紧密连锁的标记可以直接用于晋A恢复系的分子标记辅助选择.     

普通小麦Ｔ型细胞质雄性不育系及其保持系线粒体ＤＮＡ的比较研究

以小麦Ｔ细胞质雄性不育系７５－３３６９Ａ和相应保系７５－３３６９Ｂ为材料,用限制性内切酶ＢamHⅠ、EcoRⅠ、hINDⅢ完全酶解,以Ｏenothera mtDNA qtp6,小麦线粒体基因nad3/rps12、cos1为探针进行Southern杂交,杂交结果表明,７５－３３６９Ａ和 75-3369B在这３个基因上或附近有显著的组织结果差异,推测这些差异可能影响了线粒体基因组的正常功能,最终引起了７５－３３６９Ａ雄性不育。     

青花菜细胞质雄性不育系线粒体DNA的提取与RAPD分析

利用分子生物学方法提取青花菜不育系及其保持系线粒体的DNA,经琼脂糖凝胶电泳表明所提取的线粒体DNA纯度较高。通过40个引物进行随机引物多态性扩增,结果表明,由引物S66扩增出一条1 000 bp左右的特异条带BMS1000,该条带是不育系m tDNA所特有的,初步推断该特异条带可能与不育性相关。     

甘蓝型油菜细胞质雄性不育系301A线粒体不育基因片段分析

提取细胞质雄性不育系301A、212A和'陕3A'及其共同保持系'中双2号'线粒体DNA,根据已报道的Polima油菜细胞质雄性不育相关基因orf224序列设计引物,对3种不同来源的线粒体DNA PCR产物进行分析.结果显示,这3种甘蓝型油菜细胞质雄性不育材料所获得片段序列完全一致,且与已报道的Polima油菜线粒体中细胞质雄性不育相关基因orf224序列完全相同.研究表明,不育材料301A从分子角度讲属于Polima系统,不育系301A、212A和'陕3A'线粒体中与细胞质雄性不育相关线粒体基因片段orf224具有高度同源性.     

Structural and Expressional Variations of the Mitochondrial Genome Conferring the Wild Abortive Type of Cytoplasmic Male Sterility in Rice

The so-called ＂wild abortive＂ （WA） type of cytoplasmic male sterility （CMS） derived from a wild rice species Oryza rufipogon has been extensively used for hybrid rice breeding. However, extensive analysis of the structure of the related mitochondrial genome has not been reported, and the CMS-associated gene（s） remain unknown. In this study, we exploited a mitochondrial genome-wide strategy to examine the structural and expressional variations in the mitochondrial genome conferring the CMS. The entire mitochondriai genomes of a CMS-WA line and two normal fertile rice lines were amplified by Long-polymerase chain reaction into tilling fragments of up to 15.2 kb. Restriction and DNA blotting analyses of these fragments revealed that structural variations occurred in several regions in the WA mitochondrial genome, as compared to those of the fertile lines. All of the amplified fragments covering the entire mitochondrial genome were used as RNA blot probes to examine the mitochondriai expression profile among the CMS-WA and fertile lines. As a result, only two mRNAs were found to be differentially expressed between the CMS-WA and the fertile lines, which were detected by a probe containing the nad5 and orf153 genes and the other having the ribosomal protein gene rpl5, respectively. These mRNAs are proposed to be the candidates for further identification and functional studies of the CMS gene.     

叶用芥菜细胞质雄性不育系0912A的胞质效应和杂种优势分析

通过异地多代的育性鉴定及花器形态观察来调查叶用芥菜细胞质雄性不育系0912A的不育性及结籽能力;同时分别以不育系0912A和其保持系0912B为母本,与5个典型叶用芥菜自交系配成10个同核异质的杂交种,以研究hau胞质的胞质效应并测定杂种优势.结果显示:该不育系败育彻底稳定,不育株率和不育度均为100％,有正常的结籽能力;不育系杂种一代与产最相关性状的杂种优势明显,但品质性状无优势;hau胞质在单株重上的负效应较明显,在其他性状上的负效应相对较弱,但hau胞质组合F1的单株重杂种优势依然显著,且胞质效应受杂交父本核影响,通过选择合适的杂交父本配组,细胞质的负效应可以减轻或消除.     

Differential Mitochondrial Electron Transport through the Cyanide-Sensitive and Cyanide-Insensitive Pathways in Isonuclear Lines of Cytoplasmic Male Sterile, Male Fertile, and Restored Petunia

Three pairs of isonuclear lines of cytoplasmic male sterile (CMS) and fertile Petunia cells (Petunia hybrida [Hook] Vilm. and Petunia parodii L.S.M.) grown in suspension culture were examined for sensitivity to inhibitors of respiratory electron transport at time-points after transfer into fresh media. Cells from CMS lines differed from cells of fertile lines in their utilization of the cyanide-insensitive oxidase pathway. Under our culture regime, after approximately 3 days of culture cells from the CMS lines exhibited much lower cyanide-insensitive, salicylhydroxamic acid-sensitive respiration than cells from the fertile lines. This respiratory difference was shown to be specific to the mitochondrial alternative oxidase pathway by using other characteristic inhibitors of mitochondrial electron transport in experiments with isolated mitochondria. Immature anthers from CMS plants also showed lower alternative oxidase activity relative to anthers from male fertile plants, but no such difference was detected in leaf tissue, ovary or perianth tissue, or anthers collected just prior to anthesis. A cell line from a fertile plant carrying a nuclear fertility restorer gene and the CMS cytoplasm exhibited increased activity of the alternative pathway compared with the CMS lines.     

小麦胞质突变型雄性不育系85EA与其保持系线粒体DNA的比较研究

８５ＥＡ是通过电子束辐照获得的胞质突变型小麦不育要用ＲＦＬＰ和ＲＡＰＤ技术对８５ＥＡ及春保持系的线粒体ＤＮＡ进行了比较研究。ＲＦＬＰ分析表明８５ＥＡ线粒体基因组中ｃｏｘⅡ基因的位置结构与保持系发生了变化；ＲＡＰＤ分析中引物ＯＰＤ－１５扩增产物在不育系和保持系间有明显差异，不育系的扩增产物比保持系多１条分子量为０．６ｋｂ的特展览 要带，用Ｔ－ｅａｓｙ ｖｅｃｔｏｒ克隆该不育系特异条带并命名为ＯＰＤ－     

红莲型细胞质雄性不育性与线粒体渗透性转换

以水稻红莲型细胞质雄性不育(HL-CMS)的不育系粤泰A(YTA)、保持系粤泰B(YTB)以及杂种F1代红莲2号(HL2)的黄化苗为材料,研究了在不同pH及离子强度下线粒体渗透性转换(MPT)的发生及其差异。结果表明,YTA、YTB和HL2间MPT的发生均存在差别,不育系YTA线粒体渗透性转换孔(PTP)的开启与关闭对pH及离子强度的变化较保持系YTB和HL2敏感。HL2与YTA虽然具有相同的细胞质来源,但两者之间PTP及MPT的特性明显不同,前者MPT的变化与具有正常生理功能的YTB线粒体的PTP和MPT的发生特点与特性相似。这些说明红莲型水稻细胞质雄性不育的发生可能与其MPT的发生有关。     

植物细胞质雄性不育及其育性恢复的分子基础

植物细胞质雄性不育是广泛存在于高等植物中的现象,其表现为母性遗传、花粉败育,但雌蕊正常。细胞质雄性不育在杂交种子生产中起着重要作用,研究其分子作用机制有利于更有效地利用细胞质雄性不育。随着一些不育基因和恢复基因相继被克隆,人们对一些细胞质雄性不育和恢复系统的分子作用机理已经有一定了解。本文综述了近年来对植物细胞质雄性不育基因和恢复基因作用机理研究的进展。     

青花菜细胞质雄性不育相关LncRNAs的鉴定与表达分析

细胞质雄性不育系的应用可有效提高杂交种质量。该研究利用illumina测序技术鉴定青花菜细胞质雄性不育相关LncRNAs,对其靶基因和表达特征进行分析,并随机选取16个LncRNAs用qRT-PCR技术检测其表达特征,为进一步阐明LncRNA参与青花菜雄性不育发生机制提供新的路径。结果表明:(1)鉴定获得青花菜雄性不育相关LncRNAs共4326个,其中37个LncRNA在不育系及其保持系中差异表达。(2)差异LncRNAs可预测得到370个cis靶基因,这些靶基因部分为雄性不育相关的转录因子和生物蛋白。(3)XLOC_006651、XLOC_016660、XLOC_003494和XLOC_013121在不育系和保持系花蕾发育早期表达量较高,之后随着花蕾的发育,表达量逐渐下降;XLOC_021769和XLOC_038964呈先降后升的表达模式,且XLOC_038964和XLOC_012613在花蕾不同发育阶段不育系的表达量均高于保持系。(4)16个LncRNA均可在花梗、花萼、花瓣、雄蕊及雌蕊中表达,且XLOC_038964、XLOC_011575、XLOC_013157、XLOC_039677、XLOC_037356、XLOC_034182和XLOC_017574呈现出相似的表达模式,在雄蕊和花梗中表达量较低,花萼和花瓣中较高,雌蕊中表达量最高。     

玉米细胞质雄性不育及其育性恢复基因的研究进展

玉米是杂种优势利用最成功的作物之一,采用细胞质雄性不育(CMS)进行玉米杂交种生产已成为杂种优势利用的有力工具。CMS是由于细胞质和细胞核的基因表达产物的不协调而产生的不育性,可被核基因组中的恢复基因恢复。根据育性恢复专效性,玉米CMS材料主要分为T、C和S三种类型。综述了这三种类型不育及其恢复基因的研究进展,分析了在不育化制种中的应用情况。     

两个育性相关基因在几类小麦雄性不育材料中的表达研究

以1B/1R类K型不育系K3314A及其保持系3314B,非1B/1R类K型不育系732A及其保持系732B,YS温敏雄性不育小麦A3017为材料,提取不同温度处理下各时期小穗的总RNA进行反转录,对AY914051和AY660990两个目标基因进行半定量PCR和电泳分析,测定其在小麦中的表达变化趋势,以分析其与这几种不育系的育性相关关系,探讨这几种不育小麦败育的关键发育时期。结果表明,除AY914051基因在2种保持系3314B和732B中表达量变化不大之外,其它均有明显差异;2个目标基因与这几种雄性不育系的败育有关,但与育性相关程度不同,不育系两个目的基因的表达受温度变化影响程度明显大于保持系。由实验结果推测,1B/1R类K型不育系、非1B/1R类K型不育系和YS温敏雄性不育系的败育关键时期为单核期或单核期至二核期之间;温度差异可能会导致YS温敏雄性不育系的育性相关基因表达时期错位,错位后的表达差异积累可能最终导致其败育。     

水稻线粒体基因组与细胞质雄性不育研究进展

水稻线粒体基因组与细胞质雄性不育研究进展涂朱英国（武汉大学生命科学院,武汉４３００７２）ＤｅｖｅｌｏｐｍｅｎｔｏｆＲｉｃｅＭｉｔｏｃｈｏｎｄｒｉａｌＧｅｎｏｍｅａｎｄＣｙｔｏｐｌａｓｍＭａｌｅＳｔｅｒｉｌｉｔｙＴｕＪｕｎＺｈｕＹｉｎｇｇｕｏ（Ｃｏｌ...     

辣椒胞质雄性不育保持基因的分子标记

利用RAPD标记技术,以辣椒胞质雄性不育系8A及其同型保持系8B为材料,对辣椒胞质雄性不育基因和保持基因进行比较分析.结果表明:引物H7只在保持基因池有1条稳定的特异扩增带,在不育基因池未扩增出此条带,该标记可能与辣椒胞质雄性不育保持基因相连锁,命名为H7-F850.序列分析结果表明,标记H7-F850序列全长857 bp,GenBank登录号为GU208822.1.核酸序列比对结果显示,H7-F850与其具有部分同源性的片段大小均小于340 bp,未发现与其具有较高同源性的DNA序列.该RAPD标记H7-F850已成功转化为SCAR标记SF640.