Differential gene expression analysis of Cannabis sativa following Hop Latent Viroid (HLVd) eradication therapy in micropropagation tissue culture

Abstract Hop Latent Viroid (HLVd) is a significant threat to cannabis cultivation, impacting yield and quality. This study investigated the efficacy of the combination of meristem tip culture with thermotherapy in eliminating HLVd from thirteen cannabis cultivars. HLVd disease eradication was achieved in five cultivars, with varying degrees of success depending on the variety. The treatment’s effects were reproducible and persisted for several months. Long-read Nanopore cDNA sequencing of HLVd-positive and -negative samples from the cultivar ‘Annalee’ identified differentially regulated genes potentially involved in HLVd pathogenesis. These genes are implicated in cell wall architecture, cell signaling and defense, and growth-related synthesis, providing insights into HLVd’s molecular mechanisms. This study demonstrates the potential of thermotherapy for viroid clearance in Cannabis sativa , contributing to the understanding of HLVd pathology and mitigation strategies for large-scale cultivation.