Explant samples were snap-frozen in liquid nitrogen and subsequently ground into powder using a mortar and pestle, ensuring the continued presence of liquid nitrogen. The tissue powder was then combined with 300 µL of TRIzol (ThermoFisher, US), followed by the addition of 100 µL of chloroform (Sigma-Aldrich, US). After centrifugation, the RNA-rich aqueous phase was separated. RNA isolation and purification were carried out using the Nucleospin® RNA XS kit (Macherey-Nagel, Germany) according to the manufacturer's guidelines. First, non-ribosomal RNAs were enriched using the NEBNext rRNA Depletion Kit (New England Biolabs, US), starting from 15 ng RNA. Then, libraries were prepared with NEBNext Ultra II Directional RNA Library Prep Kit (New England Biolabs, US), according to manufacturer's instructions.