• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Molecular and genetic studies on the restoration of fertility in cytoplasmic male sterile petunia.
【24h】

Molecular and genetic studies on the restoration of fertility in cytoplasmic male sterile petunia.

机译：恢复细胞质雄性不育矮牵牛生殖力的分子和遗传研究。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Cytoplasmic male sterility is caused by novel chimeric mitochondrial genes whose protein products interfere with microsporogenesis. Expression of CMS genes is suppressed by one or more nuclear fertility restorer genes, thereby allowing normal pollen production. The petunia CMS-associated locus called pcf encodes a 19.5 kD protein that is highly expressed in the tapetum of floral buds. A dominant nuclear gene called restorer of fertility (Rf) suppresses CMS by dramatically reducing PCF expression.; Two homologous candidate open reading frames (designated Orf591 and Orf592 based on the number of predicted amino acids) found in a BIBAC clone identified from a genomic screen were each tested for their ability to restore fertility in CMS lines. Targeting assays using GFP fused to a putative targeting signal from Orf592 confirmed that it carries a mitochondrial transit sequence. Agrobacterium-mediated transformation of Petunia CMS lines using Orf592 caused fertility restoration in many primary transformants. A strong correlation in the presence of the transgene, reduced amount of PCF protein expression and fertility restoration was found in the primary transformants (T0) and in two T1 populations.; Both Orf591 and Orf592 DNA sequences contain pentatricopeptide (PPR) motifs; hence they were renamed Rf-PPR591 and Rf-PPR592, respectively. Unlike Rf-PPR592, Rf-PPR591 did not restore fertility in over three dozen independent transformants. The recessive allele rf-PPR592 had a 530-nt deletion in its promoter compared to the dominant allele Rf-PPR592 . Substitution of the promoter of Rf-PPR592 with the promoter of rf-PPR592 did not cause restoration in the transformants. Hence, the rf allele's inability to restore fertility is likely due to mutations in the coding region.; Transformation using the 2x35S::Rf-PPR592 transgene produced non-restored plants, probably because 35S promoter is poorly expressed in the tapetal cells. All the transgenes caused occasional abnormal phenotypes resembling meristem function mutants. These altered phenotypes may provide useful clues to the function of ancestral PPR genes or implicate the Rf gene in meristem development. Whether these phenotypes are the result of co-suppression or enhanced expression of the Rf gene or other endogenous genes remains to be determined.
机译：细胞质雄性不育是由新的嵌合线粒体基因引起的，其蛋白质产物会干扰微孢子发生。 CMS基因的表达被一种或多种核生育力恢复基因抑制，从而使花粉正常生产。与矮牵牛CMS相关的基因座，称为 pcf ，编码19.5 kD的蛋白质，在花蕾的绒毡层中高度表达。显性核基因称为生育力恢复因子（ Rf ）通过显着降低PCF表达来抑制CMS。从基因组筛选中鉴定出的BIBAC克隆中发现了两个同源候选开放阅读框（根据预测的氨基酸数量分别指定为 Orf591 和 Orf592 ）恢复CMS系的繁殖力。使用与 Orf592 的推定靶向信号融合的GFP进行的靶向测定证实，该载体带有线粒体转运序列。 Orf592 的农杆菌介导的矮牵牛CMS系的转化导致许多初级转化体恢复生育力。在原代转化子（T 0 ）和两个T 1 群体中发现了转基因的存在，PCF蛋白表达的减少和繁殖力的恢复之间的密切相关。 ; Orf591 和 Orf592 DNA序列均包含五肽（PPR）基序。因此，它们分别被重命名为 Rf-PPR591 和 Rf-PPR592 。与 Rf-PPR592不同，Rf-PPR591 不能恢复超过三打的独立转化子的繁殖力。与显性等位基因 Rf-PPR592 相比，隐性等位基因 rf-PPR592 在启动子中有530-nt缺失。用 rf-PPR592 的启动子取代 Rf-PPR592 的启动子不会引起转化体的恢复。因此， rf 等位基因无法恢复生育力可能是由于编码区的突变。使用 2x35S :: Rf-PPR592 转基因进行转化可产生未恢复的植物，这可能是因为35S启动子在绒毡层细胞中的表达较差。所有的转基因偶尔引起异常的表型，类似于分生组织功能突变体。这些改变的表型可能为祖先PPR基因的功能提供有用的线索，或暗示 Rf 基因参与分生组织的发育。这些表型是 Rf 基因或其他内源基因的共同抑制或增强表达的结果，尚待确定。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号