Transcriptome Analysis Reveals the Molecular Mechanism and Responsive Genes of Waterlogging Stress in Actinidia deliciosa Planch Kiwifruit Plants

Waterlogging stress is one of the major natural issues resulting in stunted growth and loss of agricultural productivity. Cultivated kiwifruits are popular for their rich vitamin C content and unique flavor among consumers, while commonly sensitive to waterlogging stress. The wild kiwifruit plants are usually obliged to survive in harsh environments. Here, we carried out a transcriptome analysis by high-throughput RNA sequencing using the root tissues of Actinidia deliciosa (a wild resource with stress-tolerant phenotype) after waterlogging for 0 d, 3 d, and 7 d. Based on the RNA sequencing data, a high number of differentially expressed genes (DEGs) were identified in roots under waterlogging treatment, which were significantly enriched into four biological processes, including stress response, metabolic processes, molecular transport, and mitotic organization, by gene ontology (GO) simplify enrichment analysis. Among these DEGs, the hypoxia-related genes AdADH1 and AdADH2 were correlated well with the contents of acetaldehyde and ethanol, and three transcription factors Acc26216, Acc08443, and Acc16908 were highly correlated with both AdADH1/2 genes and contents of acetaldehyde and ethanol. In addition, we found that there might be an evident difference among the promoter sequences of ADH genes from A. deliciosa and A. chinensis. Taken together, our results provide additional information on the waterlogging response in wild kiwifruit plants.