Identification and Expression Analysis of TCP Transcription Factors Under Abiotic Stress in Phoebe bournei

The gene family encodes plant transcription factors crucial for regulating growth and development. While genes have been identified in various species, they have not been studied in (Hemsl.). This study identified 29 genes in the genome, categorizing them into Class I (PCF) and Class II (CYC/TB1 and CIN). We conducted analyses on the gene at both the protein level (physicochemical properties) and the gene sequence level (subcellular localization, chromosomal distribution, phylogenetic relationships, conserved motifs, and gene structure). Most genes are localized in the nucleus, except in the mitochondria and in both the chloroplast and nucleus. Chromosomal mapping showed 29 genes unevenly distributed across 10 chromosomes, except chromosome 8 and 9. We also analyzed the promoter cis-regulatory elements, which are mainly involved in plant growth and development and hormone responses. Notably, most transcription factors respond highly to light. Further analysis revealed three subfamily genes expressed in five tissues: leaves, root bark, root xylem, stem xylem, and stem bark, with predominant genes. Using qRT-PCR, we examined six representative genes- , , , , , and -under stress conditions such as high temperature, drought, light exposure, and dark. and showed significantly higher expression under heat, drought, light and dark stress. We hypothesize that transcription factors play a key role in growth under varying light conditions, possibly mediated by auxin hormones. This work provides insights into the gene family's functional characteristics and stress resistance regulation in .