Genome-Wide Identification and Characterization of the Trihelix Transcription Factor Family in Pinus massoniana and...

Pinus massoniana Lamb. possesses considerable ecological and economic value. However, the rapid proliferation of pine wilt disease poses a significant threat to the growth and development of coniferous plants. Transcription factors play a crucial role in enabling plants to respond to external environmental stresses. The trihelix transcription factor (TTF) family, named after its unique trihelical domain (helix-loop-helix-loop-helix) and also referred to as the GT family, plays crucial roles in plant morphogenesis and in responses to biotic and abiotic stresses. In this study, we identified 56 PmGTs from the P. massoniana genome and analyzed their expression profiles in response to pine wood nematode (PWN) infection. Eight significantly differentially expressed PmGTs at various stages were selected as candidate genes for PWN resistance. Promoter analysis and qRT-PCR revealed that these genes respond to multiple treatments, including methyl jasmonate (MeJA), indole-3-acetic acid (IAA), gibberellic acid (GA3), salicylic acid (SA), and abscisic acid (ABA). Subcellular localization analysis revealed that the proteins are localized in the nucleus. Additionally, seven PmGTs exhibit transcriptional activity. This study provides a foundational understanding of the role of PmGTs in stress response in P. massoniana.