GENOME-WIDE IDENTIFICATION OF TCP TRANSCRIPTION FACTORS FAMILY IN POPULUS SECT. TURANGA (POPULUS PRUINOSA SCHRENK AND POPULUS EUPHRATICA OLIVE) REVEALED THE ROLES OF TCPS IN LEAF MORPHOLOGY

The TCP (TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTORS) gene family is a plant-specific transcription factor family and plays an important regulatory role in plant growth and development. However, the identification, characterization, and expression levels of TCPs during leaf development in Populus pruinosa and Populus euphratica remain unclear. In this study, 33 and 34 non-redundant TCPs in P. pruinosa and P. euphratica, (PpTCPs/PeTCPs) are identified, respectively, which contain TCP-conserved domains and are unevenly distributed on 19 chromosomes. Among them, PpTCP19, PpTCP27, PeTCP19, and PeTCP28 undergo positive selection in the Populus sect. Turanga. Furthermore, transcriptome data on different leaf morphologies of P. pruinosa/P. euphratica and available functional data of TCPs in Arabidopsis thaliana (AtTCP) support the involvement of the TCP gene family in the leaf development of the Populus sect. Turanga. PpTCP7, PpTCP19, PeTCP7, and PeTCP19 may regulate leaf morphology by restricting cell division at the boundaries of leaves and sepals in P. pruinosa and P. euphratica, respectively. These results elucidate a foundation for an in-depth analysis of the correlation between the expression pattern of the TCP gene and leaf morphology changes in the Populus sect. Turanga, and provide valuable information for the functional of TCP factors in the sect.