Objective To explore the regulation of GATA transcription factor gene family in the development of Jindou Kumquat (Fortunella hindsii). Method Bioinformatics was used to identify its GATA transcription factor gene family, and analyze its physicochemical properties, gene structure, phylogenetic tree and expression patterns via combining transcriptome data with RT-qPCR. Result A total of 26 FhGATAs transcription factors were identified in Jindou Kumquat, unevenly distributed on the nine chromosomes. Analysis of the physicochemical properties showed that, this family of proteins were all located in the nucleus, molecular weight in the range from 18 019.89 to 60 342.13 Da, belonging to the hydrophilic proteins, and the pI were 4.62 to 10.33. Cluster analysis with orthologous genes in Arabidopsis thaliana, FhGATA gene family can be divided into four subfamilies, the motif composition and distribution patterns were similar in the same subfamily, and some genes in the Subfamily Ⅲ were missing during evolution. Collinearity analysis showed that, 7 collinear FhGATAs genes in Jindou Kumquat, 24 AtGATAs gene pairs were homologous to the FhGATA gene in A. thaliana, 33 CsGATAs gene were homologous to FhGATA gene in Citrus sinensis. The mechanism of transcriptional regulation of FhGATA genes contained reactive elements that were light-responsive and light, and various hormone responses, stress responses, and growth and development-related. Tissue expression analysis revealed that, the four subfamilies of the FhGATAs gene family showed varying degrees of specific expression in the root, stem, leaf, flower, fruit and seed; moreover, FhGATA24, FhGATA22, FhGATA26, FhGATA18, FhGATA12 and FhGATA5 were highly expressed in the fruit. Further qRT-PCR analysis indicated that, the FhGATA gene was closely related to the single fruit weight, horizontal diameter and vertical diameter of Jindou Kumquat, among them, FhGATA22 and FhGATA18 showed significant differences in the whole fruit development of Jindou kumquat. Conclusion The Jindou kumquat contains 26 FhGATAs genes, of which FhGATA22 and FhGATA18 may be regulators mediating the fruit size.
