Comprehensive Bioinformatics and Expression Analysis of TCP Transcription Factors in Liriodendron chinense Reveals Putative Abiotic Stress Regulatory Roles

Abstract

As a magnoliid angiosperm, the Liriodendron chinense (Hamsl) Sarg in the Magnoliaceae family is susceptible to external environmental factors. The TEOSINTE BRANCHED 1/CYCLOIDEA/PROLIFERATING CELL FACTORS (TCP) proteins known for their growth and developmental biological roles have been identified in various plant species but not in the Liriodendron chinense. In this study, 15 TCP genes were identified in the L. chinense genome, and categorized into two classes, termed class I (PCF) and class II (CIN and CYC/TB1). A total of 14 TCP genes were located on the 10 chromosomes, and the remaining one, on a contig. Multispecies phylogenetic tree analysis supported the classification of identified LcTCP genes and exhibited that the expansion of the LcTCP gene family was before the angiosperm evolutionary divergence times. Additional gene duplication investigations revealed a purifying selection pressure during evolution history. Moreover, the LcTCP genes were also observed to have various cis-acting elements related to plant growth and development, phytohormone regulations, and abiotic stress responses. Gene expression pattern analysis also paraded that LcTCP genes play a crucial role in abiotic stress regulations. In particular, LcTCP1 in all stresses investigated. Overall, our findings suggest a pivotal role for the TCP gene family during external environmental stresses in L. chinense. This study will provide valuable information on the identification and function of the LcTCPs during abiotic stresses, paving the way for further research on the functional verification of L. chinense TCPs.