Genome-Wide Identification of Superoxide Dismutase and Expression in Response to Fruit Development and Biological Stress in Akebia trifoliata : A Bioinformatics Study.

Akebia trifoliata is a newly domesticated perennial fruit tree, and the lack of molecular research on stress resistance seriously affects its genetic improvement and commercial value development. Superoxide dismutase ( SOD ) can effectively eliminate the accumulation of reactive oxygen species (ROS) during the rapid growth of plant organs under biotic and abiotic stresses, maintaining a steady state of physiological metabolism. In this study, 13 SODs consisting of two FeSODs ( FSDs ), four MnSODs ( MSDs ) and seven Cu/ZnSODs ( CSDs ) were identified in the A. trifoliata genome. Structurally, the phylogeny, intron-exon pattern and motif sequences within these three subfamilies show high conservation. Evolutionarily, segmental/wide genome duplication (WGD) and dispersed duplication form the current SOD profile of A. trifoliata . Weighted gene coexpression network analysis (WGCNA) revealed the metabolic pathways of nine (69.2%) SODs involved in fruit development, among which AktMSD4 regulates fruit development and AktCSD4 participates in the stress response. In addition, under the stress of multiple pathogens, six (46.6%) SODs were continuously upregulated in the rinds of resistant lines; of these, three SODs ( AktMSD1 , AktMSD2 and AktMSD3 ) were weakly or not expressed in susceptible lines. The results pave the way for theoretical research on SODs and afford the opportunity for genetic improvement of A. trifoliata .