Comparative transcriptome analysis identifies genes involved in the regulation of the pollen cytoskeleton in a genic male sterile wheat line

Male sterility is a widespread phenomenon in plants. The regulation of the pollen cytoskeleton is closely related to fertility in wheat. In this study, the distribution of the pollen cytoskeleton was observed by fluorescence staining in the conventional controlled wheat line CP806 and the genic male sterile wheat line BS366 throughout meiosis. The distribution of microfilaments and microtubules was disordered and asymmetrical in pollen cells of BS366, and the structure of the spindle body was unclear and nearly undetectable. Based on Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses, five cytoskeleton-related KEGG pathways, four GO terms, and 35 differentially expressed genes (DEGs) were identified, including eight genes assigned to GO functions and 27 genes assigned to KEGG pathways. Additionally, 86 differentially expressed transcription factors (TFs), belonging to seven TF families, were obtained. We performed qRT-PCR assays for four genes among the eight genes identified in GO enrichment analyses, eight genes among the 27 genes identified in KEGG pathway analyses, and seven TFs from seven TF families. All of these 19 candidate genes showed disparate expression patterns in CP806 and BS366, suggesting that these genes are involved in the regulation of the pollen cytoskeleton in BS366. In addition, we found lower levels of endogenous jasmonic acid (JA) and brassinolide (BR) in BS366 than that in CP806, suggesting that the biosynthetic pathways of JA and BR are abnormal in BS366. These findings provide gene resources for clarifying cytoskeleton-mediated male sterility in genic male sterile wheat lines.