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

Abstract

The gene family PLATZ encodes transcription factors that regulate various developmentalprocesses and plant stress responses. Peanut is an allotetraploid species and one of the mostimportant edible legumes. However, its yield potential is affected by its susceptibility to multiplebiotic and abiotic stresses. The genome availability of different peanut cultivars and their diploidprogenitors provides an opportunity to get insights into genome evolution and regulation ofdifferent traits important for crop improvement. Here, we present the genome analysis of PLATZgenes in A. hypogaea (AhPLATZs) and its wild ancestors. These genes were grouped in fourdifferent phylogenetic groups defined by the distribution patterns of protein domains, as well asgene structures. Synteny analysis between diploid species and peanut subgenomes showedstructural conservation between A and B genomes, with functional innovation in B after theirevolutionary divergence. Thus, while allopolyploidization duplicated the number of genes, thefamily did not follow significant changes through genomic re-arrangements in the cultivarTifrunner. Nevertheless, comparisons between two peanut cultivars indicate that gene lossoccurred during crop diversification. Variable expression of AhPLATZs was observed acrossdifferent tissues and developmental stages, while homeologous ones generally exhibited similarexpression levels. The presence of cis-regulatory elements and interaction networks supports theinvolvement of AhPLATZs in various physiological and stress responses in peanut, includinggibberellin responsiveness, seed-specific regulation, and drought-inducibility. Moreover, thiswork provides important insights into the evolutionary fate of AhyPLATZs during the evolution ofpeanut and its wild relatives.