1. RNA-binding proteins contribute to small RNA loading in plant extracellular vesicles.
- Author
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He B, Cai Q, Qiao L, Huang CY, Wang S, Miao W, Ha T, Wang Y, and Jin H
- Subjects
- Annexins metabolism, Arabidopsis genetics, Arabidopsis immunology, Argonaute Proteins metabolism, Botrytis, DEAD-box RNA Helicases metabolism, Plant Diseases genetics, Plant Diseases immunology, Proteome, RNA, Small Interfering, Tetraspanins metabolism, Arabidopsis metabolism, Arabidopsis Proteins metabolism, Extracellular Vesicles metabolism, RNA, Plant metabolism, RNA-Binding Proteins metabolism
- Abstract
Plants use extracellular vesicles (EVs) to transport small RNAs (sRNAs) into their fungal pathogens and silence fungal virulence-related genes through a phenomenon called 'cross-kingdom RNAi'. It remains unknown, however, how sRNAs are selectively loaded into EVs. Here, we identified several RNA-binding proteins in Arabidopsis, including Argonaute 1 (AGO1), RNA helicases (RHs) and annexins (ANNs), which are secreted by exosome-like EVs. AGO1, RH11 and RH37 selectively bind to EV-enriched sRNAs but not to non-EV-associated sRNAs, suggesting that they contribute to the selective loading of sRNAs into EVs. Conversely, ANN1 and ANN2 bind to sRNAs non-specifically. The ago1, rh11 rh37 and ann1 ann2 mutants showed reduced secretion of sRNAs in EVs, demonstrating that these RNA-binding proteins play an important role in sRNA loading and/or stabilization in EVs. Furthermore, rh11 rh37 and ann1 ann2 showed increased susceptibility to Botrytis cinerea, suggesting that RH11, RH37, ANN1 and ANN2 positively regulate plant immunity against B. cinerea.
- Published
- 2021
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