Analysis of the Expression Patterns of 13 DREB Family Genes Related to Cone-Setting Genes in Hybrid Larch (Larix kaempferi × Larix olgensis)

Abstract

AP2/ERF is an important transcription factor family involved in physiological processes such as plant development and hormone signaling. In this study, based on the available transcriptome data of hybrid larch during floral induction, 13 DREB genes belonging to the AP2/EREBP family with complete CDS regions were identified through alignment using the NCBI website. We conducted a bioinformatics analysis on the gene sequences, examining their tissue specificity, response to hormone treatment, and response to environmental factors. The DREB genes in hybrid larch (Larix kaempferi × Larix olgensis) showed tissue-specific expression, with DREB7, DREB8, DREB10, DREB12, and DREB13 exhibiting higher expression levels in nascent buds and higher expression in female cones compared to male cones. They also showed high expression during signal convergence and floral induction, and were highly expressed in materials with good fertility, suggesting their positive role in the cone-setting process of hybrid larch. Additionally, 13 DREB genes were all induced by abscisic acid (ABA), gibberellin 3 (GA3), and indoleacetic acid (IAA), with the most pronounced expression changes observed after ABA treatment, indicating that these genes might be mainly regulated by ABA. In response to temperature and photoperiod treatments, DREB7, DREB8, DREB10, DREB12, and DREB13 showed significant responses, with increased expression levels induced by low temperature, while no clear pattern was observed after long or short-day treatments. These results of the study provide a reference for understanding the function of the DREB gene family in hybrid larch, offer a theoretical basis for inducing floral bud differentiation in hybrid larch, and contribute to a better understanding of the molecular mechanisms underlying cone-setting in hybrid larch.