Disease-resistant identification and analysis to transcriptome differences of blueberry leaf spot induced by beta-aminobutyric acid.

Leaf spot (Pestalotiopsis microspora) is one of the major fungal diseases in blueberry (Vaccinium corymbosum L.) production and if not treated promptly that can eventually lead to plant death. To prevent and control leaf spot effectively, we selected BABA (beta-aminobutyric acid) as an inducer, "Canlan" in blueberries of rabbit eyes varieties as experimental material and then induced and inoculated leaf spot on blueberries as an experimental group and used uninduced blueberries inoculated with leaf spot as the control group. A transcriptome sequencing library was built, allowing identification of disease resistance and transcriptome analysis. The results showed that the resistance of blueberry to leaf spot was significantly increased after induction by BABA, which can increase the activity of the enzymes PPO, POD, PAL and and β-1,3-glucanase in blueberry leaves, inducing disease resistance of blueberries to leaf spot. Transcriptome sequencing results showed that there are 3953 genes participating in the processing of disease in KEGG metabolic pathways. Among the transcripts annotated to diseases, 1115 were involved in plant-pathogen interactions and 35 were involved in anthocyanin synthesis. Differential expression results showed that there were 900 upregulated differential genes and 531 downregulated differential genes, there were 70 genes highly expressed in the library. The results of Blast2PHI database revealed that among the genes related to leaf spot disease in blueberry, there were 727 transcription factors, 200 involved in disease prevention, 45 associated with cell circulation, effector proteins and 7 pathogenic genes controlling the biosynthesis of a-(1,3)-glucan.