Genome-wide analysis of the PLATZ gene family provides insights into the genome evolution of cultivated peanut (Arachis hypogaea, Leguminosae)

The gene family PLATZ encodes transcription factors that regulate various developmental processes and plant stress responses. Peanut is an allotetraploid species and one of the most important edible legumes. However, its yield potential is affected by its susceptibility to multiple biotic and abiotic stresses. The genome availability of different peanut cultivars and their diploid progenitors provides an opportunity to get insights into genome evolution and regulation of different traits important for crop improvement. Here, we present the genome analysis of PLATZ genes in Arachis hypogaea (AhPLATZs) and its wild ancestors. These genes were grouped in four different phylogenetic groups defined by the distribution patterns of protein domains, as well as gene structures. Synteny analysis between diploid species and peanut subgenomes showed structural conservation between A and B genomes, with functional innovation in B after their evolutionary divergence. Thus, while allopolyploidization duplicated the number of genes, the family did not follow significant changes through genomic re-arrangements in the cultivar Tifrunner. Nevertheless, comparisons between two peanut cultivars indicate that gene loss occurred during crop diversification. Variable expression of AhPLATZs was observed across different tissues and developmental stages, while homeologous ones generally exhibited similar expression levels. The presence of cis-regulatory elements and interaction networks supports the involvement of AhPLATZs in various physiological and stress responses in peanut, including gibberellin responsiveness, seed-specific regulation, and drought-inducibility. Moreover, this work provides important insights into the evolutionary fate of AhyPLATZs during the evolution of peanut and its wild relatives.