Genome-wide identification and gene expression pattern analysis of the carotenoid cleavage oxygenase gene family in Fagopyrum tataricum

Carotenoid cleavage oxygenases (CCOs) convert carotenoids into volatile aromatic compounds implicated in plant growth and development. They affect the synthesis of hormones, including abscisic acid (ABA) and strigolactone (SL). However, the CCO family in Tartary buckwheat remains unelucidated. We identified the FtCCO gene family based on Tartary buckwheat genomic data and analyzed the biological function of the FtCCO genes using bioinformatics methods and the expression pattern of the gene using fluorescence quantitative PCR. Three pairs of fragment duplication genes were found in FtCCOs, and the motifs were highly conserved within the same subfamily. FtCCO genes are closely related to the dicotyledonous Arabidopsis thaliana, which has the highest number of co-linear genes. The qRT-PCR showed that among the tissue-specific expression patterns of Tartary buckwheat CCO genes, the expression of the FtCCOs was higher in the leaves. In Tartary buckwheat grain development, the relative expression of most FtCCOs was higher at the later stage. The relative expression of many genes was higher in the stems under cold, dark, NaCl, and abiotic stress conditions. However, under the hormone and plant growth regulator treatments, the expression of the nine FtCCOs was relatively low in the stems. Notably, the relative expression of FtNCED4 was extremely high under abiotic stress and hormone induction, indicating that FtNCED4 may be involved in the growth and development of Tartary buckwheat. In this study, the FtCCO family genes of Tartary buckwheat were identified at the genome-wide level, and the gene expression pattern of the FtCCO gene family in different tissues or treatments was determined. This study provides a theoretical basis for further analysis of the functions of theFtCCO family, which is of great significance for the mining of resistance genes and trait improvement.