Methods for extracting bioactive small RNAs from plants and mushrooms

A method for isolating a fraction enriched of small RNA molecules from a fungal and/or plant sample, comprising:

• a′) incubating fungal and/or plant tissue or cells with an alkali metal bicarbonate solution at a temperature of 50-100° C., separating the liquid from the solid phase to obtain a liquid phase;
• b) adding an alcohol solution to the liquid phase obtained in step a′) to obtain a solution;
• c) loading the obtained solution to a solid support able to selectively bind small RNA molecules;
• and
• d) eluting small RNA molecules from said solid support.