Evolution and Functional Dynamics of TCP Transcription Factor Gene Family in Passion Fruit (Passiflora edulis)

Passion fruit is a valued tropical fruit crop that faces environment-related growth strains. <i>TCP</i> genes are important for both growth modulation and stress prevention in plants. Herein, we systematically analyzed the <i>TCP</i> gene family in passion fruit, recognizing 30 members. Genes exhibiting closer phylogenetic relationships exhibited similar protein and gene structures. Gene members of the <i>TCP</i> family showed developmental-stage- or tissue-specific expression profiles during the passion fruit life cycle. Transcriptome data also demonstrated that many <i>PeTCPs</i> showed induced expression in response to hormonal treatments and cold, heat, and salt stress. Based on transcriptomics data, eight candidate genes were chosen for preferential gene expression confirmation under cold stress conditions. The qRT-PCR assays suggested <i>PeTCP15/16</i>/<i>17</i>/<i>19</i>/<i>23</i> upregulation, while <i>PeTCP1</i>/<i>11</i>/<i>25</i> downregulation after cold stress. Additionally, <i>TCP19</i>/<i>20</i>/<i>29</i>/<i>30</i> exhibited in silico binding with cold-stress-related miRNA319s. GFP subcellular localization assays exhibited PeTCP19/1 were localized at the nucleus. This study will aid in the establishment of novel germplasm, as well as the further investigation of the roles of <i>PeTCPs</i> and their cold stress resistance characteristics.