Spatial distribution of three ARGONAUTEs regulates the anther phasiRNA pathway

Abstract

Argonaute protein (AGO) in association with small RNAs is the core machinery of RNA silencing, an essential mechanism for precise development and defense against pathogens in many organisms. Here, we identified two AGOs in rice anthers, AGO1b and AGO1d, that interact with phased small interfering RNAs (phasiRNAs) derived from numerous long non-coding RNAs. Moreover, 3D-immunoimaging and mutant analysis indicated that rice AGO1b and AGO1d cell type-specifically regulate anther development by acting as mobile carriers of these phasiRNAs from the somatic cell layers to the germ cells in anthers. Our study also highlights a new mode of reproductive RNA silencing via the specific nuclear and cytoplasmic localization of three AGOs, AGO1b, AGO1d, and MEL1, in rice pollen mother cells.

Comparative RNA profiling identifies stage-specific phasiRNAs and co-expressedArgonautegenes in Bambusoideae and Pooideae species

“…AGO1d catalyzes the cleavage of 21- PHAS precursors (Shi et al 2022). AGO1b and AGO1d are mobile carriers of 21-nt phasiRNAs from epidermal cells to sporocytes (Tamotsu et al 2023). AGO1d, AGO5b (MALE-ASSOCIATED ARGONAUTE-1, ZmMAGO1 in maize) and AGO5c (MEIOSIS ARRESTED AT LEPTOTENE 1, OsMEL1, ZmMAGO2) are effectors of 21-nt phasiRNAs in developing meiotic cells (Komiya et al 2014; Shi et al 2022).…”

Argonaute 5-mediated antiviral defense and viral counter-defense in Nicotiana benthamiana

“…In rice ( Oryza sativa ), OsAGO5, also known as MEIOSIS ARRESTED AT LEPTOTENE1 (OsMEL1), plays a crucial role in the pre-meiotic stage of sporophytic germ cell formation ( Nonomura et al., 2007 ). It operates by binding with specific phased secondary small interfering RNAs (phasiRNAs) in the cytoplasm, eliminating unnecessary or harmful specific mRNAs during meiosis and spore development ( Komiya et al., 2014 ; Zhang et al., 2020 ; Lian et al., 2021 ; Tamotsu et al., 2023 ). The OsMEL1/ phasiRNAs complex may also regulate downstream transcription-related genes, leading to large-scale meiotic chromosome reprogramming, and promoting normal meiotic division ( Liu and Nonomura, 2016 ; Zhang et al., 2020 ).…”