Genome-wide identification of WRKY gene family members in black raspberry and their response to abiotic stresses

WRKY proteins are transcription factors in higher plants that directly or indirectly participate in plant growth and development, secondary metabolite synthesis, hormonal regulation and other physiological processes with important roles in plant abiotic and biotic stress responses. Black raspberry is an economically important small fruit with nutritious and medicinally valuable fruits, but its production is limited by environmental factors, and information about the role of WRKY genes under abiotic stress remains limited. Here, the WRKY gene family was identified and analyzed with the latest Rubus occidentalis genome data. We identified 60 RoWRKYs, 57 of which were located on 7 chromosomes of black raspberry. According to the phylogenetic analysis, 59 WRKY genes were clearly distributed iamong 3 groups (9 subgroups). Three of 10 conserved motifs were the core conserved do-mains of the RoWRKY gene family with conserved motif analysis. Subcellular localization predicted 59 WRKY genes in the nucleus, and RT-qPCR showed that 12 WRKY genes were highly expressed in one or more tissues (black fruits and leaves). Moreover, the expression difference at different treatment times indicated that the response of most WRKY transcription factors (TFs) to NaCl and ABA treatment in black raspberry is temporal. This study will provide a scientific basis for further exploration and functional verification of raspberry WRKY genes.