Fatores de transcrição WRKYs em espécies Rosaceae

Abstract

WRKY transcription factors are known to be involved in plant defense against pathogens, tolerance to different environmental stresses, and in different processes that determine plant phenological development. The identification and classification of their primary structure based on amino acid conservation and phylogenetic relationships, as well as their differential expression in response to stress tolerance in temperate fruit species, allowed for the identification of 59 RoWRKY genes in black raspberry (Rubus occidentalis), classified into four groups (I, II, III, IV) and eight subgroups (I, IIa, IIb, IIc, IId, IIe, III, IV), located on seven chromosomes, with genetic divergences of tandem and segmental duplications occurring 29.02 million years ago (Mya). Differential expression analysis of 10 RNA-seq data samples from black raspberry RoWRKY genes showed preferential or specific expression in tissue samples. In addition, a total of 667 pomWRKY genes (Malus domestica, Malus baccata, Malus sieversii, Pyrus communis, Pyrus betulifolia, Pyrus pyrifolia) were classified into four groups and nine subgroups based on domain conservation and phylogenetic relationships of amino acid sequences, with 121 members (18%) in group I, 434 (65%) in group II, 99 (15%) in group III, and 13 (2%) in group IV. Of these, 560 were mapped to the 17 chromosomes of M. domestica, M. sieverssii, P. betulifolia, P. communis, and P. pyrifolia, including 52 pairs of tandem duplicated genes. Differential expression of pomWRKY genes in 20 processed RNA-seq samples was mainly observed in groups I and II, with responses to biotic and abiotic stress in different organs of Malus spp. and Pyrus spp. These findings are important for understanding the role of WRKY family genes in plant-environment and plant-pathogen interactions, as well as for their genetic, transcriptomic, and phylogenetic importance. Therefore, identification of their structure and differential expression in genomic and transcriptomic databases allows for understanding the capacities of response and tolerance to stresses, providing the role played by WRKY genes in temperate fruit plants.