Transcriptomics analysis and candidate genes associated with Xinjiang jujube fruits in response to Alternaria alternata infection

Abstract

Black spot disease, caused by Alternaria alternata, is one of the most destructive diseases of jujube worldwide. To better understand the resistance mechanisms of jujube to A. alternata infection, two different cultivars, Zizyphus jujuba Mill. var. Junzao (susceptible) and Zizyphus jujuba Mill. var. Huizao (resistant) were tested. In this study, we identified 2235 differentially expressed genes (DEGs) in the disease-resistant cultivar and 4958 in the susceptible cultivar. Most were associated with plant phytohormone synthesis and signal transduction, flavonoid synthesis, and glutathione metabolism. The expression of six DEGs associated with disease resistance was detected by real-time quantitative polymerase chain reaction (RT-qPCR), consistent with the results of Illumina transcriptome sequencing. Moreover, the distinct expression level of the six DEGs in Jun jujube and Hui jujube, verified that these are defense response factors. The present study identified several candidate resistance genes and signal transduction pathways that may contribute to black spot disease resistance in jujube, which will assist the investigation of resistance mechanisms in the response of jujube to A. alternata infection.