Plants secrete diverse RNA onto their leaf surfaces, with a potential role in plant-microbe interactions

We discovered that Arabidopsis leaf surfaces are coated with abundant RNA, which differs from apoplastic and cellular RNA both in composition and size. Moreover, leaf surface RNA is not protected from endonuclease degradation either by extracellular vesicles or RNA-binding proteins. We found that leaf surface RNA forms cation-dependent condensates, which may contribute to the stability of these naked RNAs. We speculate that these leaf surface RNAs can be taken up by microbes during the epiphytic phase of plant-microbe interactions and thereby contribute to the homeostasis of the leaf microbiome as well as the immune response against biotic stresses.