TCP transcription factor identification in pecan (carya illinoensis) and salt tolerance function analysis of CiTCP8

The transcription factor TEOSINTE BRANCHED1/CYCLOIDEA/PCF(TCP) is a tiny family that is exclusive to plants, which is crucial for both abiotic stress and plant growth and development. Many different types of plants have been found to contain TCP transcription factors. Carya illinoensis is an important economic forest species, but the function of TCP transcription factors in pecan has not been reported so far. Based on the highly conserved TCP (PF03634) domain, we identified 35 TCP genes (CiTCPs) in pecan and divided them into three subfamilies. Analysis of conserved motifs and gene structure of the CiTCP gene family indicated that the gene family was highly conserved. Through bioinformatics and qRT-PCR analysis, we have identified a gene that may be related to salt stress, CiTCP8, which has typical transcription factor characteristics. Phenotypic analysis of CiTCP8 transgenic Arabidopsis indicates that CiTCP8 can enhance salt tolerance in plant. Overexpression of CiTCP8 in Arabidopsis enhance plant tolerance to salt stress, as determined through some physiological and biochemical indicators. In addition, the expressions of stress-related genes were also activated in CiTCP8 transgenic Arabidopsis.