Annika Usländer, Manisha V. Haag, An-Po Cheng, Bernhard Lederer, Jin Yan Khoo, Florian Dunker, Iván F. Acosta, Arne Weiberg, Caroline Gutjahr
Cross-kingdom RNA interference is an emerging concept in plant-pathogen interactions. Here we provide evidence that cross-kingdom RNA interference also occurs in a beneficial plant symbiosis called arbuscular mycorrhiza. The arbuscular mycorrhizal fungus Rhizophagus irregularis transfers small RNAs into plant cells, promoting the colonization of host roots. This finding establishes inter-organismal RNA communication as a new regulatory mechanism of this ancient and widespread symbiosis.