Genome-Wide Analysis of Snapdragon WRKY and VQ Gene Families and Their Expression in Response to Drought and Cold Stresses

Abstract

Snapdragon (Antirrhinum majus) is one of the most widely cultivated grass flowers in the world. WRKY transcription factors, VQ proteins and their interactions play crucial roles in plant response to abiotic stresses. However, little is known about WRKY and VQ gene families in snapdragon. In the present study, WRKY and VQ genes and their interactions were comprehensively analyzed in snapdragon using bioinformatics approaches, and their expression in response to drought and cold stresses was examined using real-time PCR. A total of 67 AmWRKY genes were identified in snapdragon, which were classified into different groups or subgroups based on phylogenetic analysis. Members in the same group or sub-groups exhibited similar exon-intron structure and conserved motifs distribution. Among these WRKY genes, 16 and 22 genes were found to differentially express under drought and cold stresses, respectively. A total of 32 AmVQ genes were identified, of which 10 and 18 were found to differentially express under drought and cold stresses, respectively. The WRKY-VQ or WRKY-WRKY interaction relationships were predicted for 11 cold-responsive genes, suggesting that they might exist in the same response pathway to cold stress. These results lay a foundation for further studies on roles of WRKY and VQ genes and their interactions in regulating abiotic responses in snapdragon.