Genome-wide investigation and analysis of C2H2 Zinc Finger Protein gene family in apple: Expression profiles during Penicillium expansum infection process

The gene family known as C2H2 zinc finger genes is widely recognized for its significant role in facilitating plant growth, development and reproduction. Many C2H2 zinc finger proteins (C2H2-ZFPs) have been identified and intensively studied in other plants, but little is known about their function in apples. In this study, the C2H2-ZFPs genes of apples were identified and analyzed by whole genome sequence analysis. In our study, 70 members of the C2H2-ZFPs gene family were identified in apples. Phylogenetic analyses divided the apple C2H2-ZFPs gene family into 6 subgroups, with the same subgroups having similar gene structures and motif patterns and speculating on their possible functions. After analysis based on numerous cis-elements on gene promoters, the apple C2H2-ZFPs family contained many light-responsive elements, phytohormone-responsive elements, plant growth and development-related elements, and stress-responsive elements, which indicated the diversity of their functions. The RNA-seq results of apples under P. expansum treatment revealed that fifteen C2H2-ZFPs genes were differentially expressed. The RT-qPCR further validated the same trend as transcriptome data. C2H2-ZFPs genes were significantly expressed in the process of P. expansum infestation. Our analysis evidenced that the apple C2H2-ZFPs gene family plays a vital role in the process of P. expansum infestation in apples. The identified genes can serve as potential candidates for further investigation. The present study provides new ideas for further research on the function of C2H2-ZFPs genes and the innovation of disease resistance technology in apples.