Although plants are able to withstand a range of environmental conditions, spikes in ambient temperature can impact plant fertility causing reductions in seed yield and notable economic losses 1,2. Therefore, understanding the precise molecular mechanisms that underpin plant fertility under environmental constraints is critical to safeguarding future food production 3. Here, we identified two Argonaute-like proteins whose activities are required to sustain male fertility in maize plants under high temperatures. We found that MALE-ASSOCIATED ARGONAUTE-1 and -2 associate with temperature-induced phased secondary small RNAs in pre-meiotic anthers and are essential to controlling the activity of retrotransposons in male meiocyte initials. Biochemical and structural analyses revealed how male-associated Argonaute activity and its interaction with retrotransposon RNA targets is modulated through the dynamic phosphorylation of a set of highly conserved, surface-located serine residues. Our results demonstrate that an Argonaute-dependent, RNA-guided surveillance mechanism is critical in plants to sustain male fertility under environmentally constrained conditions, by controlling the mutagenic activity of transposons in male germ cells.
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FunderThis research was supported by awards from the US National Science Foundation (nos. 1027445 to A.W.S. and 1649424 and 1754097 to B.C.M.), European Research Council (grant no. 637888 to M.D.N.) and Biotechnology and Biological Sciences Research Council (BBSRC) (nos. BB/L003023/1, BB/N005279/1, BB/N00194X/1 and BB/P02601X/1 to J.G.-M).
ASJC Scopus subject areas
- Plant Science