Genome-Wide Identification, Evolution, and Characterization of GATA Gene Family and GATA Gene Expression Analysis Post-MeJA Treatment in Platycodon grandiflorum

The GATA-binding factor (GATA) plays a major role in regulating plant development and response to distinct environmental stresses. At present, GATAs are characterized in various model plant species, including Arabidopsis thaliana and Oryza sativa. However, the GATA gene family in Platycodon grandiflorum is not yet fully understood. The study aimed to develop a comprehensive understanding of the GATA TFs and explore the regulatory mechanism of methyl jasmonate (MeJA) on the GATA members in P. grandiflorum. A total of 22 PgGATAs were identified based on publicly available genome data of P. grandiflorum, and each member was analyzed in detail. The 22 identified genes were distributed across nine chromosomes. Their phylogenetic tree and domain structures showed that the GATAs could be clustered into four subfamilies (A–D). The structural protein domains and conserved motifs of the PgGATA family members were relatively conserved across different subfamilies. Light and hormone response elements were found in abundance in the promoter sequences. In addition, quantitative real-time polymerase chain reaction (qRT-PCR) indicated that PgGATA4, 6, 7, 8, and 11 were sensitive to MeJA treatment in P. grandiflorum roots. Nevertheless, co-expression network analysis revealed that the activities of the genes in the family remained significantly correlated, suggesting possible synergy in their functions. Two (PgGATA5 and PgGATA9) and three (PgGATA8, PgGATA11, and PgGATA22) hub PgGATAs were identified that might have central functions in P. grandiflorum tissues and MeJA-treated roots, respectively. This study provided detailed information about the PgGATA gene family and facilitated a functional characterization of the candidate genes.