Indoliya Yuvraj, Tiwari Poonam, Chauhan Abhisekh Singh, Goel Ridhi, Shri Manju, Bag Sumit Kumar, Chakrabarty Debasis
Council of Scientific and Industrial Research - National Botanical Research Institute (CSIR-NBRI), Rana Pratap Marg, Lucknow-226001, India.
Academy of Scientific and Innovative Research (AcSIR), Anusandhan Bhawan, 2 Rafi Marg, New Delhi-110 001, India.
Sci Rep. 2016 Mar 14;6:23050. doi: 10.1038/srep23050.
Somatic embryogenesis is a unique process in plants and has considerable interest for biotechnological application. Compare to japonica, indica rice has been less responsive to in vitro culture. We used Illumina Hiseq 2000 sequencing platform for comparative transcriptome analysis between two rice subspecies at six different developmental stages combined with a tag-based digital gene expression profiling. Global gene expression among different samples showed greater complexity in japonica rice compared to indica which may be due to polyphyletic origin of two rice subspecies. Expression pattern in initial stage indicate major differences in proembryogenic callus induction phase that may serve as key regulator to observe differences between both subspecies. Our data suggests that phytohormone signaling pathways consist of elaborate networks with frequent crosstalk, thereby allowing plants to regulate somatic embryogenesis pathway. However, this crosstalk varies between the two rice subspecies. Down regulation of positive regulators of meristem development (i.e. KNOX, OsARF5) and up regulation of its counterparts (OsRRs, MYB, GA20ox1/GA3ox2) in japonica may be responsible for its better regeneration and differentiation of somatic embryos. Comprehensive gene expression information in the present experiment may also facilitate to understand the monocot specific meristem regulation for dedifferentiation of somatic cell to embryogenic cells.
体细胞胚胎发生是植物中的一个独特过程，在生物技术应用方面具有相当大的研究价值。与粳稻相比，籼稻对离体培养的反应较差。我们使用Illumina Hiseq 2000测序平台，结合基于标签的数字基因表达谱分析，对两个水稻亚种在六个不同发育阶段进行了比较转录组分析。不同样本间的全局基因表达显示，粳稻比籼稻具有更高的复杂性，这可能是由于两个水稻亚种的多系起源。初始阶段的表达模式表明，原胚性愈伤组织诱导阶段存在主要差异，这可能是观察两个亚种间差异的关键调节因子。我们的数据表明，植物激素信号通路由复杂的网络组成，且频繁发生相互作用，从而使植物能够调节体细胞胚胎发生途径。然而，这种相互作用在两个水稻亚种间存在差异。粳稻中分生组织发育正向调节因子（即KNOX、OsARF5）的下调及其对应物（OsRRs、MYB、GA20ox1/GA3ox2）的上调，可能是其体细胞胚胎更好再生和分化的原因。本实验中的综合基因表达信息也可能有助于理解单子叶植物中体细胞去分化为胚性细胞的特定分生组织调控。
