Potential candidate genes and pathways related to cytoplasmic male sterility in Dianthus spiculifolius as revealed by transcriptome analysis.

KEY MESSAGE: We introduced the candidate gene DsHSP70 into Arabidopsis thaliana, resulting in male gametophyte sterility and abnormal degeneration of sepals and petals. Cytoplasmic male sterility (CMS) is a useful tool for hybrid production. However, the regulatory mechanism of CMS in Dianthus spiculifolius remains unclear. In this study, we investigated whether male-sterile line of D. spiculifolius has a malformed tapetum and fails to produce normal fertile pollen. RNA sequencing technology was used to compare the gene expression patterns of the D. spiculifolius male-sterile line and its male fertility maintainer line during anther development. A total of 12,365 differentially expressed genes (DEGs) were identified, among which 1765 were commonly expressed in the S1, S2 and S3 stages. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses indicated that these DEGs were mainly involved in oxidation-reduction processes, signal transduction and programmed cell death. Additionally, weighted correlation network analysis (WGCNA) showed that three modules may be related to male sterility. A putative regulatory pathway for the male sterility traits was constructed based on the reproductive development network. After introducing the candidate DsHSP70 gene into Arabidopsis thaliana, we found that overexpressing plants showed anther abortion and shorter filaments, and accompanied by abnormal degeneration of sepals and petals. In summary, our results identified potential candidate genes and pathways related to CMS in D. spiculifolius, providing new insights for further research on the mechanism of male sterility.