miR2118-triggered phased siRNAs are differentially expressed during the panicle development of wild and domesticated African rice species

• Published in: Rice (New York, N.Y.) Vol. 9; no. 1; p. 10
• Main Authors: Ta, K. N., Sabot, F., Adam, H., Vigouroux, Y., De Mita, S., Ghesquière, A., Do, N. V., Gantet, P., Jouannic, S.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.12.2016; Springer Nature B.V; Springer Open
• Subjects: Agriculture; Biomedical and Life Sciences; Gene expression; Life Sciences; Original; Original Article; Oryza barthii; Oryza glaberrima; Plant Breeding/Biotechnology; Plant Ecology; Plant Genetics and Genomics; Plant populations; Plant Sciences; Ribonucleic acid; Rice; RNA; Domestication; Small RNAs; Meristem; Panicle; phasiRNAs; miR2118; Oryza barthii; Oryza glaberrima
• ISSN: 1939-8425; 1939-8433; 1934-8037
• DOI: 10.1186/s12284-016-0082-9

Background Rice exhibits a wide range of panicle structures. To explain these variations, much emphasis has been placed on changes in transcriptional regulation, but no large-scale study has yet reported on changes in small RNA regulation in the various rice species. To evaluate this aspect, we performed deep sequencing and expression profiling of small RNAs from two closely related species with contrasting panicle development: the cultivated African rice Oryza glaberrima and its wild relative Oryza barthii . Results Our RNA-seq analysis revealed a dramatic difference between the two species in the 21 nucleotide small RNA population, corresponding mainly to miR2118 -triggered phased siRNAs. A detailed expression profiling during the panicle development of O. glaberrima and O. barthii using qRT-PCRs and in situ hybridization, confirmed a delayed expression of the phased siRNAs as well as their lncRNA precursors and regulators ( miR2118 and MEL1 gene) in O. glaberrima compared to O. barthii . We provide evidence that the 21-nt phasiRNA pathway in rice is associated with male-gametogenesis but is initiated in spikelet meristems. Conclusion Differential expression of the miR2118 -triggered 21-nt phasiRNA pathway between the two African rice species reflects differential rates of determinate fate acquisition of panicle meristems between the two species.