A Transcriptomic Analysis of Early Adventitious Roots of Rosa chinensis Cuttings and Key Genes Screening

In order to study the key gene regulation mechanism of Rosa chinensis cuttings in the process of adventitious root formation, the Illumina platform sequencing technology was used to analyze the three developmental stages of cutting rose cultivar 'Carola', i.e., adventitious root initiation period, callus formation period and adventitious root elongation period. A transcriptome sequencing analysis was performed on the 1 cm cortex at the base of cuttings. The results showed that at the three stages of adventitious root formation of rose cuttings, a total of 5 033 differentially expressed genes were screened between the adventitious root initiation stage and the callus formation stage, of which 2 313 genes were up-regulated and 2 720 genes were down-regulated; a total of 1 865 differentially expressed genes were screened between the callus formation period and adventitious root elongation period, of which 1 332 genes were up-regulated and 533 genes were down-regulated. The GO functional analysis showed that differentially expressed genes were mainly involved in the 3 major functions of biological process, molecule function and cell composition. The KEGG enrichment analysis showed that the differentially expressed genes were mainly involved in the metabolic pathways of plant hormone signal transduction, the synthesis of secondary metabolites and the synthesis of carbohydrates. The changes in the transcription levels of the 8 genes that exhibited the most significant differences in the rooting process were detected with real-time fluorescent quantitative PCR. The results showed that the verification results of real-time fluorescent quantitative PCR were basically consistent with the results of transcriptome sequencing.