Genome-Wide Identification and Characterization of the TCP Gene Family in Cucumber (Cucumis sativus L.) and Their Transcriptional Responses to Different Treatments

Abstract

TCP proteins are plant-specific transcription factors widely implicated in leaf morphogenesis and senescence, flowering, lateral branching, hormone crosstalk, and stress responses. However, the relationship between the transcription pattern of <i>TCPs</i> and organ development in cucumber has not been systematically studied. In this study, we performed a genome-wide identification of putative <i>TCP</i> genes and analyzed their chromosomal location, gene structure, conserved motif, and transcript expression. A total of 27 putative <i>TCP</i> genes were identified and characterized in cucumber. All 27 putative <i>CsTCP</i> genes were classified into class I and class II. Class I comprised 12 <i>CsTCPs</i> and Class II contained 15 <i>CsTCPs</i>. The 27 putative <i>CsTCP</i> genes were randomly distributed in five of seven chromosomes in cucumber. Four putative <i>CsTCP</i> genes were found to contain putative miR319 target sites. Quantitative RT-PCR revealed that 27 putative <i>CsTCP</i> genes exhibited different expression patterns in cucumber tissues and floral organ development. Transcript expression and phenotype analysis showed that the putative <i>CsTCP</i> genes responded to temperature and photoperiod and were induced by gibberellin (GA)and ethylene treatment, which suggested that <i>CsTCP</i> genes may regulate the lateral branching by involving in multiple signal pathways. These results lay the foundation for studying the function of cucumber <i>TCP</i> genes in the future.