1. Genomewide analysis of small RNAs in nonembryogenic and embryogenic tissues of citrus: micro RNA- and si RNA-mediated transcript cleavage involved in somatic embryogenesis.
- Author
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Wu, Xiao‐Meng, Kou, Shu‐Jun, Liu, Yuan‐Long, Fang, Yan‐Ni, Xu, Qiang, and Guo, Wen‐Wu
- Subjects
PLANT embryology ,MICRORNA ,GENOMES ,SOMATIC embryogenesis ,CITRUS ,SMALL interfering RNA ,GENETIC transcription in plants - Abstract
Somatic embryogenesis ( SE) is a process of somatic cells becoming dedifferentiated and generating embryos. SE has been widely used in biotechnology as a powerful way of regeneration and a model system for studying plant embryogenesis, but the controlling mechanisms of SE are far from clear. Here, we show the genomewide profiles of mi RNAs/si RNAs and their target genes in nonembryogenic and embryogenic tissues of 'Valencia' sweet orange. By high-throughput sequencing ( HTS) of small RNAs and RNA degradome tags, we identified 50 known and 45 novel mi RNAs, 130 miniature inverted-repeat transposable elements ( MITEs) derived, 94 other and 235 phased small interfering RNAs (si RNAs), as well as 203 target genes. The majority of the abundantly expressed mi RNAs/si RNAs exhibit lower expression levels in embryogenic callus ( EC) or during SE process than in nonembryogenic callus ( NEC), which is supposed to derepress the target genes that are involved in development and stress response, thus to activate the biological processes required for cell differentiation. However, the conserved csi-miR156a/b, miR164b and 171c directed suppression of specific transcription factors ( TFs) are supposed to inactivate the postembryonic growth thus to maintain normal SE. In this study, mi RNA- and si RNA-mediated silencing of target genes was found under sophisticated regulation in citrus SE system; the enhancement effect of specific conserved mi RNAs on SE was discussed, providing new clues for future investigation of mechanisms that control SE. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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