马协型水稻细胞质雄性不育系线粒体基因组的变异与功能的研究

马协型水稻细胞质雄性不育系是近年培育并广泛应用的一种新型不育系。利用Southern blot、Northern blot和Blue-native PAGE电泳等技术对其线粒体基因组的变异和功能进行研究,分析其雄性不育的分子机理。发现其不育系线粒体基因组中除有一个正常的cox2基因外还存在一个多余的拷贝,且分别转录成不同的转录本。Blue-native PAGE电泳显示,不育系线粒体呼吸链复合物IV的活性明显低于保持系。     

水稻配子体、孢子体细胞质雄性不育系线粒体蛋白质的分析

利用SDS-聚丙烯酰胺凝胶电泳方法分析了水稻配子体细胞质雄性不育系粤泰A、保持系粤泰B、F_1代泰优2号、恢复系胜优2号和孢子体细胞质雄性不育系马协A、保持系马协B、F_1代马协63、恢复系明恢63及另一种孢子体细胞质雄性不育系珍汕97A、保持系珍汕97B、F_1代汕优63、恢复系明恢63黄化苗的线粒体蛋白质。结果表明,粤泰A、B、F_1、恢复系之间出现6条多肽带的差异,马协A、B、F_1、恢复系之间出现4条多肽带的差异,珍汕97A、B、F_1、恢复系之间出现2条多肽带的差异。     

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.     

BT型细胞质雄性不育水稻及其三系的线粒体DNA研究

用RAPD技术对BT型水稻胞质雄性不育系秀A及其保持系秀B、恢复系湘晴以及杂种F1代的线粒体DNA进行了比较分析。结果表明不育系与其保持系间存在显著差异;不育系与其F1之间mtDNA也存在差异。在引物OPJ－08的扩增产物中,秀A扩增出一条分子量为800bp的多态性片段,在引物OPK－10的扩增产物中,杂种F1扩增出一条分子量为900bp的片段。把这两片段回收、克隆并制备探针,OPJ－08800的Southern杂交结果显示不育系与其F1杂交图谱存在多态性;OPK－10900的Suthern杂交结果显示不育系与其保持系同存在差异。推测这两片段与育性可能有一定的联系。     

水稻红莲型细胞质雄性不育系与保持系mtRNA差异显示和差别片段？…

将Ｔ４ＲＮＡ连接酶和ＡＦＬＰ技术特点相结合构建于适于ｍｔＲＮＡ的差异显示方法,并比较水稻（Ｏｒｙｚａ ｓａｔｉｖａ Ｌ．）红莲型细胞质雄性不育系,保持系和杂种一代ｍｔＲＮＡ差异。在４组引物对的选择扩增产物中共找到６个差异片段,其中差异条带ＤＴＡ为不育系仅有,条带ＤＡＢ为不育系和保持系特有,而条带ＤＢＦ１、ＤＢＦ２、ＤＢＦ３、ＤＢＦ４为保持系和Ｆ１杂种共有。这表明水稻红莲型不育系粤泰Ａ与杂种一代泰优     

红莲型细胞质雄性不育水稻线粒体DNA的AP-PCR分析

为了研究红莲型细胞质雄性不育与线粒体基因组的关系。以水稻红莲型粤泰细胞质雄性不育系A和保持系B及杂种一代F1为材料。应用AP-PCR分析,用10个单引物对其线粒体DNA进行扩增。实验结果表明,不同的引物在3种材料间均有不同程度的差异。为红莲型细胞质雄性不育分子机理的研究提供了线索;此外,在引物6F1的扩增图谱中找到一条在YTA和F1中特异的带TAF6F2,Sounthern分析TAF6F2不育胞质的特异性,可能与红莲型水稻细胞质雄性 不育性状的形成有关。     

水稻红莲型细胞质雄性不育系与保持系mtRNA差异显示和差别片段的分析

将T4 RNA连接酶和AFLP技术特点相结合构建了适于mtRNA的差异显示方法 ,并比较了水稻 (OryzasativaL .)红莲型细胞质雄性不育系、保持系和杂种一代mtRNA的差异。在 4组引物对的选择扩增产物中共找到 6个差异片段 ,其中差异条带DTA为不育系仅有 ,条带DAB为不育系和保持系特有 ,而条带DBF1、DBF2 、DBF3 、DBF4 为保持系和F1杂种共有。这表明水稻红莲型不育系粤泰A与杂种一代泰优 2号mtRNA的差异大于保持系粤泰B和杂种一代泰优 2号mtRNA的差异。Northern杂交证实条带DTA在不育系、保持系和杂种一代的转录确有差异 ,表明它与红莲型细胞质雄性不育有关。条带DTA全长 2 5 9bp ,尽管未发现有同源序列和新的开放阅读框 ,但它可作为探针从cDNA文库中筛选全基因序列 ,进而寻找与细胞质雄性不育有关的开放阅读框架。     

细胞质雄性不育水稻线粒体基因组的RFLP分析

利用RFLP技术,比较研究了在农业生产上广泛应用的9种细胞质雄性不育体系的线粒体基因组,结果表明：1）9种水稻雄性不育细胞质的遗传相似性变化范围为0．615～1．000。所有配子体雄性不育细胞质的遗传相似性变化范围为0．6431．000,其中QXA,DY1A和YM15A这3种细胞质的遗传相似性为1．000。所有孢子体雄性不育细胞质的遗传相似性为1．000,2）在配子体细胞质雄性不育水稻中,用3个探针（atpa,atp9＋nad6,cox2）与2种内切酶（HindⅢ,BamHⅠ）的组合未发现不育系与保持系之间的多态性,但在探针atp6,cob,和had2的杂交带型中找到了不育系和保持系之间的一些差异。YTA和YTB在5个探针．内切酶组合（atp61HindⅢ,coblHindⅢ,atp61BamHⅠ,coblBamHⅠ,nad21BamHⅠ）中存在差异。3种细胞质（QX,SJ,DY1）的不育系和保持系之间的差异是相同的,都出现在atp6／HindⅢ,atp6／BamHⅠ,cob／BamHⅠ等3个组合中。YM15A和YM15B在4个组合（atp6／HindⅢ,atp6／BamHⅠ,cob／BamHⅠ,nad2／BamHⅠ）中存在差异。LYA和LYB的差异出现在cob／HindⅢ,cob／BamHⅠ,nad2／BamHⅠ这3个组合中;3）在孢子体细胞质雄性不育水稻中,所有不育系的带型是一样的,所有保持系的带型也一样。不育系和保持系的差异出现在atp6／HindⅢ,cob／HindⅢ,atp6／EcoR,Ⅰcob／EcoRⅠ,cox1／EcoRⅠ,atp6／BamHⅠ,cob／BamHⅠ,cox1／BamHⅠ,cox2／BamHⅠ等9个组合中。这些结果在分子水平上揭示了9种雄性不育细胞质的线粒体基因组存在结构多样性,并为其细胞质雄性不育分子机理的研究打下了基础。     

D^2型小麦细胞质雄性不育系及其保持系和恢复系线粒体DNA的比较研究

ｍｓＤ２－ＣＡ８０５７是新育成的具有粗厚山羊草（Ａｅ．ｃｒａｓａ,６ｘ）胞质的Ｄ２型小麦细胞质雄性不育系。采用ＲＦＬＰ和ＲＡＰＤ方法对该不育系及其具有普通小麦（Ｔ．ａｅｓｔｉｖｕｍ）胞质的保持系ＣＡ８０５７和恢复系保－７６９－２２－６的线粒体ＤＮＡ进行分析和比较,发现该不育系的线粒体ＤＮＡ组织结构明显不同于其保持系,也不同于其恢复系。Ｓｏｕｔｈｅｒｎ结果表明,该不育系线粒体基因组在ａｔｐＡ、ａｔｐ９、ｃｏｂ和ｃｏｘⅡ基因上或附近具有显著的组织结构差异。ＲＡＰＤ分析证实了这一点。相反,ＲＦＬＰ和ＲＡＰＤ结果都表明保持系与恢复系之间线粒体基因组结构非常相似。这支持了该不育系的胞质遗传特点来源于与普通小麦胞质差异较大的野生型胞质的事实。推测这种胞质差异与育性有关     

Properties of the Circular Plasmid-like DNA Bl from Mitochondria of Cytoplasmic Male-sterile Rice

Mitochondrial DNA from suspension-cultured cells of the cytoplasmicmale-sterile rice line, A-58 CMS, was shown to contain fourminicircular DNAs. We chose for further examination the largestminicircular DNA, designated Bl. A molecular clone containingthe complete sequence of Bl was constructed and used to probemitochondrial and nuclear genomes by Southern hybridization.No evidence was found for the existence of integrated copiesof Bl in the main mitochondrial genomes of either male-sterileor fertile rice. Sequences homologous to Bl, however, were foundin nuclear genomes of both the male-sterile and the fertilerice. The complete nudeotide sequence of Bl (2,135 bp) was determined,and found to contain sequences homologous to those in the 1,913bp plasmid-like DNA of maize. (Received May 15, 1987; Accepted July 20, 1987)     

几个水稻品种抽穗期主效基因与微效基因的定位研究

在构建２张ＲＦＬＰ图谱的基础上,定位分析了控制水稻抽穗期的主效基因和微效基因。在特三矮２号／Ｃ．Ｂ．群体中定位到２个主效基因和２个微效基因。该２个主基因分别位于第３、８染色体上,累加贡献率约达５０％,加性效应值分别为７天和６天,而分别位于第１、１２染色体的２个微效基因的贡献率仅分别为８．３％和９．６％,加性效应值仅为３天和４天。在外引２号／Ｃ．Ｂ．群体中定位了２个连锁于第６染色体的主效基因和１个位于第８染色体的微效基因,该２个主效基因的贡献率分别为３５．５％和２７．４％,来自外引２号的该２个基因其效应均为明显推迟抽穗,因而可推测它们为感光性基因,微效基因的贡献率仅为８．９％,基因效应值较小。     

Comparison of Rice (Oryza sativa L.) Seed Proteins from Several Varieties

Enzymatically modified proteins (EMP) with different methionine levels were produced from soy protein isolate using an improved plastein reaction. The products having methionine at approximate levels of 4%, 7%, and 14%, designated as EMP₄, EMP₇, and EMP₁₄, respectively, were investigated to characterize their chemical properties particularly in terms of the state and location of the methionine residues. Leucine aminopeptidase treatment of the EMP products did not find any significant amount of methionine residues at the N-terminals, but carboxypeptidase A treatment liberated methionine efficiently in accordance with the methionine levels in the EMP products. Treatment with LiBH₄ reduced the methionine content of EMP₁₄ by approximately 64%. A significant amount of homoserine was produced when EMP₁₄ was treated with BrCN. All these data indicate that the covalently attached methionine molecules are localized at or near the C-terminals of the EMP molecules, probably as oligomers.     

Protein Synthesis in Isolated Mitochondria of Rice (Oryza sativa L.) Seedlings

For studies of in organello mitochondrial protein synthesis in rice, Oryza sativa L., conventional surface-sterilization procedures were demonstrated to be ineffective. Because of the over-whelmingly efficient [³⁵S]methionine utilization by contaminating bacteria, even “essentially bacteria-free” rice mitochondria were shown to be unsuitable for the study of in organello protein synthesis. We developed a procedure to obtain a bacteria-free preparation of rice mitochondria. Such mitochondria favored a membrane-dependent ATP-generating system over an external ATP-generating system as the energy supplement for in organello protein synthesis. Two distinct classes of [³⁵S]methionine-labeled, cycloheximide-insensitive products were detected: an electrophoretically unresolved population and a set of some 22 to 27 discrete polypeptide species, each with a characteristic electrophoretic mobility and relative abundance.     

Robustness and Strategies of Adaptation among Farmer Varieties of African Rice (Oryza glaberrima) and Asian Rice (Oryza sativa) across West Africa

This study offers evidence of the robustness of farmer rice varieties (Oryza glaberrima and O. sativa) in West Africa. Our experiments in five West African countries showed that farmer varieties were tolerant of sub-optimal conditions, but employed a range of strategies to cope with stress. Varieties belonging to the species Oryza glaberrima – solely the product of farmer agency – were the most successful in adapting to a range of adverse conditions. Some of the farmer selections from within the indica and japonica subspecies of O. sativa also performed well in a range of conditions, but other farmer selections from within these two subspecies were mainly limited to more specific niches. The results contradict the rather common belief that farmer varieties are only of local value. Farmer varieties should be considered by breeding programmes and used (alongside improved varieties) in dissemination projects for rural food security.     

Evolutionary Genomics of Structural Variation in Asian Rice (Oryza sativa) Domestication

Structural variants (SVs) are a largely unstudied feature of plant genome evolution, despite the fact that SVs contribute substantially to phenotypes. In this study, we discovered SVs across a population sample of 347 high-coverage, resequenced genomes of Asian rice (Oryza sativa) and its wild ancestor (O. rufipogon). In addition to this short-read data set, we also inferred SVs from whole-genome assemblies and long-read data. Comparisons among data sets revealed different features of genome variability. For example, genome alignment identified a large (∼4.3 Mb) inversion in indica rice varieties relative to japonica varieties, and long-read analyses suggest that ∼9% of genes from the outgroup (O. longistaminata) are hemizygous. We focused, however, on the resequencing sample to investigate the population genomics of SVs. Clustering analyses with SVs recapitulated the rice cultivar groups that were also inferred from SNPs. However, the site-frequency spectrum of each SV type—which included inversions, duplications, deletions, translocations, and mobile element insertions—was skewed toward lower frequency variants than synonymous SNPs, suggesting that SVs may be predominantly deleterious. Among transposable elements, SINE and mariner insertions were found at especially low frequency. We also used SVs to study domestication by contrasting between rice and O. rufipogon. Cultivated genomes contained ∼25% more derived SVs and mobile element insertions than O. rufipogon, indicating that SVs contribute to the cost of domestication in rice. Peaks of SV divergence were enriched for known domestication genes, but we also detected hundreds of genes gained and lost during domestication, some of which were enriched for traits of agronomic interest.     

Maize Mitochondria: Cytochromes of Fertile and Cytoplasmic Male-sterile Lines

Cytochromes a + a₃, b, and c of mitochondria prepared from fertile and cytoplasmic male-sterile single- and double-cross maize (Zea mays L.) lines were examined by difference spectra at 25 C. The sterile lines contained the full complement of cytochromes, and absorption maxima were identical for each fertile-sterile combination. A small, but significant, increase of b cytochromes was detected in each sterile line, whereas the quantities of cytochromes a + a₃ and c were essentially unchanged. The yield of mitochondrial protein per gram of tissue was higher for the single-than for the double-cross, whereas the sterile cytoplasm did not affect ultimate mitochondrial yield.     

水稻广亲和性和胞质雄性不育恢复性的遗传分析

对经花培育成的广亲和恢复系ＴＧ７、ＴＧ８的遗传分析表明：ＴＧ７、ＴＧ８均带有１对广亲和基因,与ＣＰＳＬＯ１７、０２４２８的广亲和基因等位。广亲和基因与雄性不育恢复基因表现为独立遗传,野败型（籼）和滇－Ｉ型（粳）不育胞质的育性恢复基因非等位。ＴＧ７和ＴＧ８分别带有２对野败不育胞质和１对滇－Ｉ型不育胞质的恢复基因,分别来自亲本明恢６３和ＣＰＳＬＯ１７。     

水稻花药培养力的遗传分析及基因定位

在栽培稻的籼粳亚种间,花药培养力存在显著差异,这一差异主要是由遗传因素引起的。以适合籼粳稻杂种花药培养的SK_3培养基,经花药培养获得了一个籼粳交F_1代的加倍单倍体(DH)群体,对该群体的110个株系用同一种培养基进行花药培养,利用该群体构建的分子图谱进行有关水稻花药培养力的数量性状基因座位(QTLs)的分析。结果表明,与水稻花药培养力有关的4个性状在DH群体中均表现为连续分布,愈伤组织诱导率与绿苗分化率之间不存在相关性,而绿苗产率与愈伤组织诱导率和绿苗分化率均显著相关。在第6、7、8、10和12 5条染色体上分别检测到与愈伤组织诱导率有关的5个QTLs,其加性效应均为正。在第1和第9染色体上检测到与绿苗分化率有关的2个QTLs,这两个性状间的QTs不存在连锁。在第9染色体上有一个主效基因与白苗分化率有关,对绿苗产率则没有检测到特有的QTL。     

水稻光敏素基因(phyA)和-1,5-二磷酸核酮糖羧化酶/加氧酶小亚基基因(rbcS)的染色体定位

以生物素标记的水稻单拷贝光敏素基因（ｐｈｙＡ） 和１ ,５二磷酸核酮糖羧化酶／ 加氧酶小亚基基因（ｒｂｃＳ） 的基因组克隆为探针,其大小分别为６ ．６ 和１ ．１ ｋｂ ,通过原位杂交技术将它们分别定位到水稻染色体上。ｐｈｙＡ 和ｒｂｃＳ基因的检出率分别为２９ ．７９ ％ 和２１ ．５６ ％ 。ｐｈｙＡ在第３ 染色体上有３ 个座位：长臂近着丝粒、短臂末端、长臂中部。ｒｂｃＳ分别定位于第７ 染色体长臂近着丝粒（８ ．６２ ％ ） 、第５ 染色体长臂末端、第６ 染色体长臂距着丝粒近２／３ 处。此外,对信号转导相关基因定位的意义,水稻染色体的准确识别、功能基因在染色体上的分布及位置意义等也进行了讨论。