Key Cannabis Salt-Responsive Genes and Pathways Revealed by Comparative Transcriptome and Physiological Analyses of Contrasting Varieties

Abstract

For the dissection and identification of the molecular response mechanisms to salt stress in cannabis, an experiment was conducted surveying the diversity of physiological characteristics. RNA-seq profiling was carried out to identify differential expression genes and pathway which respond to salt stress in different cannabis materials. The result of physiological diversity analyses showed that it is more sensitive to proline contents in K94 than in W20; 6 h was needed to reach the maximum in K94, compared to 12 h in W20. For profiling 0–72 h after treatment, a total of 10,149 differentially expressed genes were identified, and 249 genes exhibited significantly diverse expression levels in K94, which were clustered in plant hormone signal transduction and the MAPK signaling pathway. A total of 371 genes showed significant diversity expression variations in W20, which were clustered in the phenylpropanoid biosynthesis and plant hormone signal transduction pathway. The pathway enrichment by genes which were identified in K94 and W20 showed a similar trend to those clustered in plant hormone signal transduction pathways and MAPK signaling. Otherwise, there were 85 genes which identified overlaps between the two materials, indicating that these may be underlying genes related to salt stress in cannabis. The 86.67% agreement of the RNA-seq and qRT-PCR indicated the accuracy and reliability of the RNA-seq technique. Additionally, the result of physiological diversity was consistent with the predicted RNA-seq-based findings. This research may offer new insights into the molecular networks mediating cannabis to respond to salt stress.