In grasses, two types of phased, small interfering RNAs (phasiRNAs) are expressed largely in young, developing anthers. They are 21 or 24 nucleotides (nt) in length and are triggered by miR2118 or miR2275, respectively. However, most of their functions and activities are not fully understood. We performed comparative genomic analysis of their source loci ( We found that 21‐nt phasiRNAs with a 5′‐terminal uridine (U) demonstrated We hypothesised that successful initiation of phasiRNA biogenesis is conservatively maintained, while phasiRNA products diverged quickly and are not individually conserved. In particular, phasiRNA production is under the control of multiple reciprocal regulation mechanisms.
Phased secondary siRNAs (phasiRNAs) are broadly present in the reproductive tissues of flowering plants, with spatial–temporal specificity. However, the ARGONAUTE (AGO) proteins associated with phasiRNAs and their miRNA triggers remain elusive. Here, through histological and high‐throughput sequencing analyses, we show that rice AGO1d, which is specifically expressed in anther wall cells before and during meiosis, associates with both miR2118 and miR2275 to mediate phasiRNA biogenesis. AGO1d preferentially binds to miR2118‐triggered 21‐nucleotide (nt) phasiRNAs with a 5′‐terminal uridine, suggesting a dual role in phasiRNA biogenesis and function. Depletion of AGO1d causes a reduction of 21‐ and 24‐nt phasiRNAs and temperature‐sensitive male sterility. At lower temperatures, anthers of the These results uncover an essential role of AGO1d in rice anther development at lower temperatures and demonstrate coordinative roles of AGO proteins during reproductive phasiRNA biogenesis and function.
- Award ID(s):
- 1754097
- NSF-PAR ID:
- 10392941
- Publisher / Repository:
- Wiley-Blackwell
- Date Published:
- Journal Name:
- New Phytologist
- Volume:
- 236
- Issue:
- 4
- ISSN:
- 0028-646X
- Page Range / eLocation ID:
- p. 1529-1544
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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