Identification and characterization of GRAS transcription factors in Panax quinquefolius and their potential roles in cold tolerance

Panax quinquefolius L. is a perennial medicinal herb particularly vulnerable to recurring cold stress throughout its life cycle. The GRAS family constitutes a class of plant-specific transcription factors with pivotal functions in growth, development, and environmental adaptation. Nevertheless, a comprehensive characterization of the GRAS transcription factor family in P. quinquefolius remains lacking. A total of 123 PqGRAS members were identified and classified into 13 subfamilies. Transcriptomic profiling implicated that the PAT1 and DELLA subfamilies likely play pivotal roles in integrating multiple environmental and hormonal signals to coordinate complex stress-adaptive responses in P. quinquefolius . Notably, PqGRAS086 (PAT1 subfamily) was significantly upregulated under both cold and methyl jasmonate (MeJA) treatments. Within the 2,000 bp upstream promoter of PqGRAS086 , MeJA-responsive regulatory elements were enriched, whereas low-temperature-responsive elements were entirely absent. Phylogenetic analysis further revealed that PqGRAS086 clustered with VaPAT1 , PtrPAT1 , and ZjCIGR1 , which have been demonstrated to play a positive regulatory role in enhancing plant cold tolerance. RT-qPCR analysis further demonstrated that exogenous MeJA enhanced PqGRAS086 expression during cold exposure, suggesting indirect involvement of PqGRAS086 in cold stress through the JA signaling pathway. This study provides the first genome-wide characterization of GRAS genes in P. quinquefolius and identifies PqGRAS086 as a candidate target for future functional studies and molecular breeding.