高等植物胞质雄性不育及育性恢复的分子生物学研究进展

综述了几种植物胞质雄性不育的分子机理研究进展,着重介绍了与细胞质雄性不育相关的线粒体连锁位点的分析及育性恢复的几种假说,并对今后的研究进行了讨论。     

植物细胞质雄性不育及其育性恢复的分子生物学研究进展

植物细胞质雄性不育（CMS）和恢复系统在作物杂交种子生产中具有重要的意义。综述了目前已发现的与植物CMS相关的线粒体DNA位点,育性恢复基因对CMS相关DNA位点表达的影响,育性恢复基因的分子标记定位、克隆,及育性恢复分子机理等方面的研究进展,并讨论了恢复基因在植物分子育种上的应用。     

植物细胞质雄性不育及育性恢复研究进展

植物细胞质雄性不育是一种广泛存在于高等植物中的母性遗传性状。细胞质雄性不育不仅为研究核质互作提供了良好材料,同时也是植物杂种优势利用的重要基础,其分子机理是目前研究的重点。多种研究证据表明,线粒体基因与细胞质雄性不育密切相关。随着分子生物学和分子遗传学的不断发展,许多植物的恢复基因已经被定位和克隆,进一步阐明了植物细胞质雄性不育和育性恢复的分子机理。本文综述了近几年植物中细胞质雄性不育和育性恢复相关基因的研究进展,并探讨了细胞质雄性不育/育性恢复系统在育种方面的应用。     

植物细胞质雄性不育性与育性恢复的分子生物学研究进展

植物细胞质雄性不育性与育性恢复的分子机理一直是分子生物学的研究热点。文章综述了近十年来的主要研究进展。包括：1、线粒体不育相关区域的确定及其特点;2、不育相关区域的表达谱;3、产生细胞质雄性不育的可能机理;4、恢复基因的可能调控方式;5、恢复基因的遗传、定位及其特征等。拟兰芥、水稻等模式植物线粒体基因组测序工作已经完成,其有关生物学信息及后续研究将极大地推动植物细胞质雄性不育研究取得更快进展。     

小麦K、V型胞质雄性不育育性恢复的细胞学研究

以Ｋ、Ｖ型１Ｂ／１Ｒ不育系分别和四个非１Ｂ／１Ｒ恢复系杂交,观察了异质杂种小麦的花粉母细胞减数分裂。以Ｔ型细胞质和普通小麦胞质作比较,研究了Ｋ、Ｖ型异源细胞质对１Ｂ·１Ｂ／１Ｒ杂合核型染色体配对的影响。实验结果表明,Ｋ、Ｖ胞质背景下,育性恢复度与１Ｂ·１Ｂ／１Ｒ杂合核型染色体配对行为不直接相关。减数分裂中期Ⅰ、Ｋ、Ｖ、Ｔ型异源细胞质对杂合核型染色体配对的影响随父本遗传背景不同而异。后期Ⅰ,三类异质小麦杂种Ｆ１代均出现了不正常分离,后期Ⅰ和后期Ⅱ出现了落后染色体,四分体时期出现了微核。三类异源细胞质对落后染色体率和微核率的影响因不同遗传背景而异。     

植物细胞器离体翻译技术与胞质雄性不育性

不能产生正常花药、花粉或雄配子的植物称之为雄性不育植物。根据其遗传特点可将其分为细胞核雄性不育 (ｇｅｎｉｃｍａｌｅｓｔｅｒｉｌｉｔｙＧＭＳ)和细胞质雄性不育 (ｃｙｔｏｐｌａｓｍｉｃｍａｌｅｓｔｅｒｉｌｉｔｙＣＭＳ)。ＣＭＳ植物在自然界中广泛存在。植物ＣＭＳ在杂种优势利用方面具有极其重要意义 ,迄今胞质雄性不育机理尚未完全搞清。植物一般有三套遗传信息共同指导它的生命活动 ,即核ＤＮＡ(ｎＤＮＡ)以及线粒体ＤＮＡ(ｍｔＤＮＡ)和叶绿体ＤＮＡ(ｃｐＤＮＡ)。ＣＭＳ的研究很自然地集中于线粒体与叶绿体。根据比较限制性…     

小麦K,V型胸质雄性不育育性恢复的细胞学研究

以Ｋ、Ｖ型１Ｂ／１Ｒ不育系分别和四个非１Ｂ／１Ｒ恢复系杂交,观察了异质杂种小麦的花粉母细胞减数分裂。以Ｔ型细胞质和普通小麦胞质作比较,研究了Ｋ、Ｖ型异源细胞质对１Ｂ·１Ｂ／１Ｒ杂合核型染色体配对的影响。实验结果表明,Ｋ、Ｖ胞质背景下,育性恢复度与１Ｂ·１Ｂ／１Ｒ杂合核型染色体配对行为不直接相关。减数分裂中期Ｉ、Ｋ、Ｖ、Ｔ型异源细胞质对杂合核型染色体配对的影响随父本遗传背影不同而异。后期Ｉ,三类异质     

核编码的育性恢复基因

细胞质雄怀不育现象涉及线粒体基因组中的不良基因与核编码的育性恢复基因的相互作用。文章介绍了有关恢复基因对线粒体ＣＭＳ基因表达的影响方式、恢复基因定位和克隆方面的研究进展。     

几种小麦雄性不育系育性恢复性的比较研究

以三种小麦胞质雄性不育系(Q型不育系、T型不育系和 AL型不育系)与 13 个 Q型胞质恢复系进行杂交,以花粉碘染率为指标,比较研究了不同恢复系对不同不育系的恢复度。研究发现,尽管 Q型胞质恢复系本身育性正常,但它与Q型不育系杂交后所得 F1 代,育性有较大变幅,花粉碘染率 0.177 7~0.774 7。有些恢复系如QR3、QR3 37、QR30207等对AL型不育系、恢复系 QR2 143 对 T型不育系的恢复度(杂种花粉碘染率)较高,达0.85以上。在对供试恢复系对不同不育系的恢复度进行 t检验后发现,这三种不育系在恢复程度上无显著差别,说明它们可能是同类不育系,或者可能是所涉及的恢复系具有广泛恢复能力。在上述三种类型不育系中,QA92 8的可恢复程度偏低,其原因可能是其核遗传背景不同。     

Molecular basis of cytoplasmic male sterility and fertility restoration in rice

Cytoplasmic male sterility (CMS) is a maternally inherited trait that causes dysfunctions in pollen and anther development. CMS is caused by the interaction between nuclear and mitochondrial genomes. A product of a CMS-causing gene encoded by the mitochondrial genome affects mitochondrial function and the regulation of nuclear genes, leading to male sterility. In contrast, the RESTORER OF FERTILITY gene (Rf gene) in the nuclear genome suppresses the expression of the CMS-causing gene and restores male fertility. An alloplasmic CMS line is often bred as a result of nuclear substitution, which causes the removal of functional Rf genes and allows the expression of a CMS-causing gene in mitochondria. The CMS/Rf system is an excellent model for understanding the genetic interactions and cooperative functions of mitochondrial and nuclear genomes in plants, and is also an agronomically important trait for hybrid seed production. In this review article, pollen and anther phenotypes of CMS, CMS-associated mitochondrial genes, Rf genes, and the mechanism that causes pollen abortion and its agronomical application for rice are described.     

高等植物细胞质雄性不育分子机理的研究进展

从线粒体DNA、叶绿体DNA和线粒体质粒DNA方面较详细地阐述了高等植物细胞质雄性不育的分子机理及最新进展;探讨了细胞核DNA和细胞质DNA之间的相互关系。     

Mitochondrial gene expression and cytoplasmic male sterility in sorghum

Variation in sorghum mitochondrial translation products has enabled fertile (Kafir) cytoplasm to be distinguished from Milo cytoplasmic male sterile cytoplasm and from three alternative sources of cytoplasmic male sterile cytoplasm. Mitochondria from Milo cytoplasm synthesised a 65 000 mol. wt. polypeptide which was not synthesised by those from Kafir cytoplasm. In the cytoplasmic male sterile combination of Kafir nucleus in Milo cytoplasm synthesis of this polypeptide was dramatically increased. Mitochondria from two cytoplasmic male sterile lines (Kafir nucleus in IS1112 cytoplasm and Yellow Feterita nucleus in M35-1 cytoplasm) did not synthesise the 65 000 mol. wt. polypeptide but synthesised additional high molecular weight polypeptides (from 54 000 to 82 000 mol. wt.), the major one being 82 000. Mitochondria from cytoplasm IS1112 were also distinguished by synthesis of an additional 12 000 mol. wt. polypeptide. Mitochondria from the cytoplasmic male sterile line Martin nucleus in 9E cytoplasm synthesised an additional 42 000 mol. wt. polypeptide but did not synthesise a 38 000 mol. wt. polypeptide detected in all other cytoplasms. Immunoprecipitation of mitochondrial translation products with antiserum raised against subunit I of yeast cytochrome oxidase tentatively identified the 38 000 mol. wt. polypeptide as subunit I of sorghum cytochrome oxidase. The 42 000 mol. wt. polypeptide was also immuno-precipitated by this antiserum and thus is probably an altered form of cytochrome oxidase subunit I.Analysis of native mitochondrial DNA by agarose gel electrophoresis revealed the presence of two plasmid-like DNA species of molecular weight 5.3 and 5.7 kb in the cytoplasmic male sterile lines Kafir nucleus in cytoplasm IS1112 and Yellow Feterita nucleus in M35-1 cytoplasm. Thus there is a positive correlation between the synthesis of the 82 000 mol. wt. polypeptide and the presence of the additional DNA species.     

The fertility restorer gene, Rf2, for Lead Rice-type cytoplasmic male sterility of rice encodes a mitochondrial glycine-rich protein

Cytoplasmic male sterility (CMS) is associated with a mitochondrial mutation that causes an inability to produce fertile pollen. The fertility of CMS plants is restored in the presence of a nuclear-encoded fertility restorer (Rf) gene. In Lead Rice-type CMS, discovered in the indica variety 'Lead Rice', fertility of the CMS plant is restored by the single nuclear-encoded gene Rf2 in a gametophytic manner. We performed map-based cloning of Rf2, and proved that it encodes a protein consisting of 152 amino acids with a glycine-rich domain. Expression of Rf2 mRNA was detected in developing and mature anthers. An RF2-GFP fusion was shown to be targeted to mitochondria. Replacement of isoleucine by threonine at amino acid 78 of the RF2 protein was considered to be the cause of functional loss in the rf2 allele. As Rf2 does not encode a pentatricopeptide repeat protein, unlike a majority of previously identified Rf genes, the data from this study provide new insights into the mechanism for restoring fertility in CMS.     

小麦T型细胞质雄性不育系与可育系叶片蛋白质双向电泳分析

利用育性恢复基因(Rf3)的近等基因系1031-1、S-165和1031-1与S-165之间的正交与反交,创建了四个实验品系(1031-1、S-165、不育品系、反交品系);采用改进的蛋白质聚丙烯酰胺凝胶双向电泳技术,从发育遗传学的角度,对小麦T型细胞质雄性不育和可育株旗叶表达的相关蛋白产物进行差异分析。通过对旗叶蛋白的双向电泳分析,发现4个品系有相近的蛋白质双向电泳图谱。没有相应穗中差异蛋白质的出现。从蛋白质水平上证实了不育基因与恢复基因表达具有器官特异性特征。     

Mitochondrial ORF79 levels determine pollen abortion in cytoplasmic male sterile rice

Cytoplasmic male sterility (CMS) is an important agricultural trait characterized by lack of functional pollen, and caused by ectopic and defective mitochondrial gene expression. The pollen function in CMS plants is restored by the presence of nuclear‐encoded restorer of fertility (Rf) genes. Previously, we cloned Rf2, which restores the fertility of Lead Rice (LD)‐type CMS rice. However, neither the function of Rf2 nor the identity of the mitochondrial gene causing CMS has been determined in LD–CMS rice. Here, we show that the mitochondrial gene orf79 acts as a CMS‐associated gene in LD–CMS rice, similar to its role in BT–CMS rice originating from Chinsurah Boro II, and Rf2 weakly restores fertility in BT–CMS rice. We also show that RF2 promotes degradation of atp6–orf79 RNA in a different manner from that of RF1, which is the Rf gene product in BT–CMS rice. The amount of ORF79 protein in LD–CMS rice was one‐twentieth of the amount in BT–CMS rice. The difference in ORF79 protein levels probably accounts for the mild and severe pollen defects in LD–CMS and BT–CMS rice, respectively. In the presence of Rf2, accumulation of ORF79 was reduced to almost zero and 25% in LD–CMS and BT–CMS rice, respectively, which probably accounts for the complete and weak fertility restoration abilities of Rf2 in LD–CMS and BT–CMS rice, respectively. These observations indicate that the amount of ORF79 influences the pollen fertility in two strains of rice in which CMS is induced by orf79.