Cross-kingdom RNA in plant–microbe interactions: from molecular interactions to next-generation crop protection

Cross-kingdom RNA (CK-RNA) communication is an advanced concept that enhances our understanding of inter-kingdom interactions by uncovering RNA-mediated signaling among plants, fungi, bacteria, and viruses. This review provides a detailed overview of CK-RNA mechanisms, highlighting on plant–microbe interactions. Through RNA interference (RNAi), CK-RNA allows organisms to exchange regulatory signals that influence gene expression, defense responses, metabolism, and adaptive processes across kingdoms. Furthermore, this review highlights agricultural applications of CK-RNA, including Spray-Induced Gene Silencing (SIGS), Host-Induced Gene Silencing (HIGS) and Microbe-Induced Gene Silencing (MIGS) which offer environmentally friendly and sustainable alternatives to conventional chemical management. Overall, the integration of CK-RNAs as target and MIGS as delivery method presents a promising pathway for viable, environmentally friendly crop protection that aligns with modern goals of environmental sustainability and agricultural resilience.