Zhai Lulu, Xu Liang, Wang Yan, Zhu Xianwen, Feng Haiyang, Li Chao, Luo Xiaobo, Everlyne Muleke M, Liu Liwang
National Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, P.R. China.
College of Plant Science, Jilin University, Changchun 130062, P.R. China.
Sci Rep. 2016 Feb 23;6:21652. doi: 10.1038/srep21652.
Embryogenesis is an important component in the life cycle of most plant species. Due to the difficulty in embryo isolation, the global gene expression involved in plant embryogenesis, especially the early events following fertilization are largely unknown in radish. In this study, three cDNA libraries from ovules of radish before and after fertilization were sequenced using the Digital Gene Expression (DGE) tag profiling strategy. A total of 5,777 differentially expressed transcripts were detected based on pairwise comparison in the three libraries (0_DAP, 7_DAP and 15_DAP). Results from Gene Ontology (GO) and pathway enrichment analysis revealed that these differentially expressed genes (DEGs) were implicated in numerous life processes including embryo development and phytohormones biosynthesis. Notably, some genes encoding auxin response factor (ARF ), Leafy cotyledon1 (LEC1) and somatic embryogenesis receptor-like kinase (SERK ) known to be involved in radish embryogenesis were differentially expressed. The expression patterns of 30 genes including LEC1-2, AGL9, LRR, PKL and ARF8-1 were validated by qRT-PCR. Furthermore, the cooperation between miRNA and mRNA may play a pivotal role in the radish embryogenesis process. This is the first report on identification of DEGs profiles related to radish embryogenesis and seed development. These results could facilitate further dissection of the molecular mechanisms underlying embryogenesis and seed development in radish.
胚胎发生是大多数植物物种生命周期中的一个重要组成部分。由于胚胎分离困难，萝卜中参与植物胚胎发生的全球基因表达，尤其是受精后的早期事件，在很大程度上尚不清楚。在本研究中，采用数字基因表达（DGE）标签分析策略对萝卜受精前后胚珠的三个cDNA文库进行了测序。基于三个文库（0_DAP、7_DAP和15_DAP）的成对比较，共检测到5777个差异表达转录本。基因本体论（GO）和通路富集分析结果表明，这些差异表达基因（DEGs）参与了包括胚胎发育和植物激素生物合成在内的众多生命过程。值得注意的是，一些已知参与萝卜胚胎发生的编码生长素反应因子（ARF）、叶状子叶1（LEC1）和体细胞胚胎发生受体样激酶（SERK）的基因差异表达。通过qRT-PCR验证了包括LEC1-2、AGL9、LRR、PKL和ARF8-1在内的30个基因的表达模式。此外，miRNA和mRNA之间的合作可能在萝卜胚胎发生过程中起关键作用。这是关于鉴定与萝卜胚胎发生和种子发育相关的DEGs图谱的首次报道。这些结果有助于进一步剖析萝卜胚胎发生和种子发育的分子机制。
