Screening of transcription factors related to flower and fruit development by differential gene analysis in Lycium species

Lycium barbarum Thunb. and Lycium ruthenicum Murray (wolfberries) have been utilized as traditional medicinal and nutritional plants in China for centuries. Much research has been focused on their high quality, yet the molecular mechanisms underlying morphological differences remain unclear. In this study, a comparative analysis of morphological and cytological characteristics indicated that significant differences existed. Meanwhile, transcriptomic analyses of the flower and fruit were performed at different developmental stages, and a total of 54 795 differentially expressed genes (DEGs) were screened. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses showed that these DEGs were significantly enriched in substance metabolism, catalytic activity, single organism process, starch and sucrose metabolism, carotenoid biosynthesis, amino sugar and nucleotide sugar metabolism, phenylpropanoid biosynthesis, and other pathways. Based on these significantly enriched pathways, the ratio between nonsynonymous and synonymous substitution rates (Ka/Ks), and numerous studies related to flower and fruit development, we preliminarily screened eight transcription factor families related to flower and fruit development and counted the number of potential transcription factor genes. These candidate genes could provide a basis for future functional verification, helping to further research on the molecular mechanism of morphological differences in the two Lycium species.