Identification and expression pattern analysis of WRKY gene family in jackfruit under low temperature stress postprint

Abstract: The WRKY genes of transcription factors plays an important role in plant biological and abiotic stress responses, a total of 61 members of the WRKY genes of that jackfruit (Artocarpus heterophyllus) were identified based on the whole genome of jackfruit and the expression profile of WRKY genes in jackfruit under low temperature stress were analyzed by bioinformatics method and real-time fluorescence quantitative PCR (qRT-PCR). The results were as follow: (1) Phylogenetic tree analysis showed that jackfruit, Arabidopsis thaliana and rice (Oryza sativa) WRKY genes were divided into four subfamilies. (2) Chromosome localization showed that 61 AhWRKY genes were unevenly distributed on 23 chromosomes. (3) Analyses of conserved motifs and gene structure showed that AhWRKY genes located in the same subfamily had similar conserved motifs and gene structure. (4) Phylogenetic analysis revealed 124 pairs of fragment duplicated genes within AhWRKY genes. Inter-species analysis showed jackfruit exhibits a greater number of homologous gene pairs with Arabidopsis thaliana than rice and fig (Ficus carica), and 8 genes formed homologous gene pairs in Arabidopsis thaliana, rice and fig. (5) Transcriptomic analysis of different varieties of jackfruit under low temperature stress showed that there the expression patterns of WRKY genes differed in different varieties. Moreover, qRT-PCR analysis further verified this result, indicating that WRKY genes play a role in response to low temperature stress in jackfruit of different varieties. This study provides new insights into the evolution and function of WRKY genes, and lays a foundation for functional research and utilization of WRKY genes in jackfruit.