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bioRxiv · 10.1101/2024.06.12.598608

Comparative transcriptome profiling identifies stage-specific phasiRNAs and co-expressed Argonaute genes in Bambusoideae and Pooideae species

Belanger, S.·Zhan, J.·Yu, Y.·Meyers, B.
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Abstract

PhasiRNAs (phased, small interfering RNAs) play a crucial role in supporting male fertility in grasses. Earlier work in maize (Zea mays) and rice (Oryza sativa) - and subsequently many other plant species - identified premeiotic 21-nt and meiotic 24-nt phasiRNAs. More recently, a group of premeiotic 24-nt phasiRNAs were discovered in the anthers of two Pooideae species, barley (Hordeum vulgare) and bread wheat (Triticum aestivum). The conservation of premeiotic 24-nt phasiRNAs and other classes of reproductive phasiRNAs across Pooideae species remains unclear. We conducted a comparative RNA profiling of three anther stages in six Pooideae species and one Bambusoideae species. We observed complex temporal accumulation patterns of 21-nt and 24-nt phasiRNAs in Pooideae and Bambusoideae grasses. In Bambusoideae, 21-nt phasiRNAs accumulated during meiosis, whereas 24-nt phasiRNAs were present in both premeiotic and postmeiotic stages. We identified premeiotic 24-nt phasiRNAs in all seven species examined. These phasiRNAs exhibit distinct biogenesis mechanisms and potential Argonaute effectors compared to meiotic 24-nt phasiRNAs. We show that specific Argonaute genes co-expressed with stage-specific phasiRNAs are conserved across Bambusoideae and Pooideae species. Our degradome analysis identified a set of conserved miRNA target genes across species, while 21-nt phasiRNAs targets were species-specific. Cleavage of few targets was observed for 24-nt phasiRNAs.

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Belanger, S., Zhan, J., Yu, Y., Meyers, B.. 2024-06-14. Comparative transcriptome profiling identifies stage-specific phasiRNAs and co-expressed Argonaute genes in Bambusoideae and Pooideae species. https://doi.org/10.1101/2024.06.12.598608

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