Identification and expression pattern analysis of RopGEF family genes in <italic>Chenopodium quinoa</italic>

In plants, RopGEF-mediated ROP signaling plays a crucial role in cellular signaling pathways. In this study, seven RopGEF family members were identified in Chenopodium quinoa through bioinformatics analysis and were found to be distributed across six chromosomes. Based on phylogenetic relationships and structural characteristics, 90 RopGEFs from six crop species, including Arabidopsis thaliana and rice, were classified into four subfamilies. Evolutionary analysis revealed that CqRopGEF5 is closely related to AtRopGEF1 and OsRopGEF1. Structural analysis indicated that the exon-intron organization, protein motif composition, and secondary and three-dimensional structures of CqRopGEFs are highly conserved. qRT-PCR analysis showed that most CqRopGEFs were highly expressed during seed germination, with expression levels in seedling roots being higher than in stems and leaves. Their expression was significantly induced by exogenous abscisic acid (ABA) and abiotic stresses. For instance, the expression of CqRopGEF2, CqRopGEF3, CqRopGEF4, and CqRopGEF7 initially increased and then decreased under ABA treatment, while CqRopGEF7 was strongly downregulated under both cold and heat stress. In conclusion, the CqRopGEF gene family exhibits conserved evolutionary structure and may play important roles in quinoa growth and development, ABA signaling, and responses to abiotic stress.