Mobile plant miRNAs allow communication within and between organisms

Plant microRNAs (miRNAs) are small regulatory RNAs that are encoded by endogenous miRNAgenes and regulate gene expression through gene silencing, by inducing degradation of theirtarget messenger RNA or by inhibiting its translation. Some miRNAs are mobile molecules insidethe plant, and increasing experimental evidence has demonstrated that miRNAs representmolecules that are exchanged between plants, their pathogens, and parasitic plants. It has alsobeenshownthatmiRNAsaresecretedintotheexternalgrowingmediumandthatthesemiRNAsregulate gene expression and the phenotype of nearby receiving plants, thus defining a newconcept in plant communication. However, the mechanism of miRNA secretion and uptake byplant cells still needs to be elucidated