Cloning, analysing and homologous expression of TCP4 transcription factor under abiotic stress and hormone signal in Fraxinus mandschurica

TCP genes encode a plant-specific transcription factor family, which acts as a key role in regulating plant growing development and stress response. This paper reveals the FmTCP4 expression pattern under abiotic stress and hormonal signal induction, in an attempt to lay the foundation for the study of gene function in stress response and regulation of growing development in ashtree (Fraxinus mandschurica). We had cloned TCP gene named FmTCP4 from ashtree in our previous research. The molecular structure of FmTCP4 was analyzed by bioinformatics software. Abiotic stress by low temperature(4 ℃), salt (NaCl) and water-deficit, and hormonal signal induced by abscisic acid (ABA) and gibberellin (GA3) were used to induce FmTCP4 in the study for analyzing the expression patterns. Bioinformatics analysis showed that FmTCP4 was 1 251 bp, and contained the complete ORF, encoding 416 amino acids(Genebank ID:KX905155). FmTCP4 had a helix-loop-helix structure, encoding a hydrophilic unstable protein, and no signal peptide but transmembrane ability, existed in the nucleus by analysing subcellular localization prediction, and played an important role in the regulation of cytoplasm to the nucleus. The results of homology sequence comparison showed that FmTCP4 had high homology with sesame, tobacco and other species. After abiotic stress treatments, FmTCP4 gene expression levels varied with abiotic stress time, but the trend was different, showing that FmTCP4 significantly responded to the three kinds of abiotic stress. The results of FmTCP4 gene expression after the induction by hormone signal were significantly different compared with the control group, suggesting that exogenous plant hormones had regulated the transcription expression of FmTCP4 gene. The analysis about FmTCP4 gene expression after the induction by abiotic stress and hormonal signal indicated that FmTCP4 gene had responded to abiotic stress (cold, salt, drought) and hormone signal, meaning that FmTCP4 involved in the balance of growing development and stress response.