College of Horticulture, Shenyang Agricultural University, Shenyang 110866, Liaoning, China; College of Forestry, Shenyang Agricultural University, Shenyang 110866, Liaoning, China.
College of Forestry, Shenyang Agricultural University, Shenyang 110866, Liaoning, China.
Gene. 2018 Nov 30;677:280-288. doi: 10.1016/j.gene.2018.07.075. Epub 2018 Aug 1.
Clivia miniata var. variegata (Cmvv) typically possesses yellow- and green-striped leaves. The striped plant not only has a high ornamental value but also be suitable for photosynthesis and chloroplast development research. Our previous study had revealed that yellow stripes (YSs) of Cmvv leaves contain chlorophyll-less ineffective chloroplasts. However, mechanism of Cmvv variegation is yet to be investigated. In the study, transcriptomes of both the YSs and green stripes (GSs) from single Cmvv leaves were compared using high-throughput sequencing. A total of 688 differential expression genes (DEGs) were identified based on biological replications. The qRT-PCR results indicated that transcriptome profiles accurately reflected global transcriptome differences between YSs and GSs. Subcellular localization analysis suggested that 56 DEG proteins were targeted to chloroplasts, and might be involved in anterograde signaling and leaf patterning. Moreover, the DEGs were mostly enriched in photosynthesis and plant-pathogen interaction KEGG pathways. Meanwhile, there should be coordination interaction between the two pathways. Seven of the eight DEGs involved in photosynthesis KEGG pathway were chloroplast-encoded genes and distributed among different cistrons of chloroplast DNA (cpDNA) large single copy regions (LSC) which are more prone to mutation. It was proposed that the YSs were caused by mutation(s) in cpDNA LSC. Thus, when the primary zygote of Cmvv was chimeric in LSC, leaf might be yellow- and green-striped. The study would give new insights into plant variegation and offers candidate genes to guide future research attempting to breed variegated plants.
朱顶红黄花重瓣变种（Cmvv）通常具有黄、绿相间的条纹叶片。这种具有条纹的植物不仅具有很高的观赏价值，而且适合光合作用和叶绿体发育研究。我们之前的研究表明，Cmvv 叶片的黄色条纹（YSs）含有无叶绿素的无效叶绿体。然而，Cmvv 斑驳形成的机制尚未得到研究。在这项研究中，使用高通量测序比较了单个 Cmvv 叶片的 YSs 和绿色条纹（GSs）的转录组。基于生物重复，共鉴定了 688 个差异表达基因（DEGs）。qRT-PCR 结果表明，转录组谱准确反映了 YSs 和 GSs 之间的全转录组差异。亚细胞定位分析表明，56 个 DEG 蛋白靶向叶绿体，可能参与正向信号转导和叶片图案形成。此外，DEGs 主要富集在光合作用和植物-病原体相互作用 KEGG 途径中。同时，这两个途径之间应该存在协调相互作用。参与光合作用 KEGG 途径的 8 个 DEGs 中有 7 个是叶绿体编码基因，分布在叶绿体 DNA（cpDNA）大片段重复区域（LSC）的不同顺反子中，这些区域更容易发生突变。提出 YSs 是由 cpDNA LSC 中的突变引起的。因此，当 Cmvv 的初级合子在 LSC 中嵌合时，叶片可能是黄、绿相间的。该研究将为植物斑驳形成提供新的见解，并为指导未来试图培育斑驳植物的研究提供候选基因。
