The Mosaic Mutants of Cucumber: A Method to Produce Knock-Downs of Mitochondrial Transcripts.
The Mosaic Mutants of Cucumber: A Method to Produce Knock-Downs of Mitochondrial Transcripts.
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DOI：
10.1534/g3.115.017053
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发表时间：
2015-04-14
期刊：
影响因子：
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通讯作者：
Havey MJ
中科院分区：
文献类型：
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作者：
Del Valle-Echevarria AR;Kiełkowska A;Bartoszewski G;Havey MJ
细胞质对植物生产性能的影响是有充分证据的，它是细胞器和核基因产物之间密切相互作用的结果。在植物中，线粒体基因的缺失、突变或嵌合通常与有害的表型以及经济上重要的性状（如用于产生杂交种子的细胞质雄性不育）有关。目前，由于没有有效产生线粒体突变体的方法，对线粒体功能和核相互作用的遗传分析受到限制。黄瓜（Cucumis sativus L.）具有独特的细胞器遗传特性，包括三个植物基因组（母系为质体，父系为线粒体，双亲本为细胞核）的差异传递，一个相对较大的线粒体DNA，其中重复基序之间的重组产生重排。以及在野生型植物通过细胞培养传代后出现的强马赛克（MSC）父系遗传表型的存在，这些表型在线粒体DNA中具有独特的重排。我们对三个独立生产的MSC细胞系的线粒体DNA进行了测序，发现了相对于野生型亲本系，这些区域中线粒体基因转录不足和转录减少。质谱和Western blots并没有证实MSC突变系线粒体蛋白质组的转录差异，这表明转录后事件，如蛋白质寿命，可能补偿MSC线粒体转录减少。我们的研究结果支持黄瓜作为一个模型系统来产生线粒体基因的转录“敲低”，这有助于研究对植物性能重要的线粒体反应和核相互作用。
Cytoplasmic effects on plant performance are well-documented and result from the intimate interaction between organellar and nuclear gene products. In plants, deletions, mutations, or chimerism of mitochondrial genes are often associated with deleterious phenotypes, as well as economically important traits such as cytoplasmic male sterility used to produce hybrid seed. Presently, genetic analyses of mitochondrial function and nuclear interactions are limited because there is no method to efficiently produce mitochondrial mutants. Cucumber (Cucumis sativus L.) possesses unique attributes useful for organellar genetics, including differential transmission of the three plant genomes (maternal for plastid, paternal for mitochondrial, and bi-parental for nuclear), a relatively large mitochondrial DNA in which recombination among repetitive motifs produces rearrangements, and the existence of strongly mosaic (MSC) paternally transmitted phenotypes that appear after passage of wild-type plants through cell cultures and possess unique rearrangements in the mitochondrial DNA. We sequenced the mitochondrial DNA from three independently produced MSC lines and revealed under-represented regions and reduced transcription of mitochondrial genes carried in these regions relative to the wild-type parental line. Mass spectrometry and Western blots did not corroborate transcriptional differences in the mitochondrial proteome of the MSC mutant lines, indicating that post-transcriptional events, such as protein longevity, may compensate for reduced transcription in MSC mitochondria. Our results support cucumber as a model system to produce transcriptional “knock-downs” of mitochondrial genes useful to study mitochondrial responses and nuclear interactions important for plant performance.