Analyze Transcriptome Of Vitis Pesudoreticulata ‘baihe-35-1’ Induced By Erysiphe Necator Schw.

Powdery mildew(PM), which is caused by the pathogen Erysiphe necator Schw., is the single most damaging disease of cultivated grapes(Vitis vinifera) worldwide. RNA-seq analysis was used for deep sequencing of the leaf transcriptome to study PM resistance in Chinese wild grapes(V. pseudoreticulata Baihe-35-1). Firstly, we using four reads mapping software Bowtie2, HISAT, SOAP2 and TopHat2, compare the reads mapping quality, and the efficiency. Then we using HISAT mapping results to compare the transcripts assemble by StringTie and Cufflinks, and analysis the alternative splicing events in the assemble transcripts. At last, we analysis the differentially expressed gene(DEG) to find out the resistance related gene, for the gene deeply analysis and breeding protophase work. We find that,(1) HISAT much better than other three software, not only in mapping validity, but also in reads mapping reads number;(2) StringTie assemble a better grape tanscripts and identified more alternative splicing events than Cufflinks;(3)Among the sequences obtained, 6541 genes were differentially expressed(DEG) and were annotated with Gene Ontology terms and by pathway enrichment. The significant categories that were identified included the following: defense, salicylic acid(SA) and jasmonic acid(JA) responses; systemic acquired resistance(SAR); hypersensitive response; plant–pathogen interaction; flavonoid biosynthesis; and plant hormone signal transduction;(4)Various putative secretory proteins were identified, indicating potential defense responses to PM infection. In all, 318 putative R-genes and 183 putative secreted proteins were identified, including the defense-related R-genes BAK1, MRH1 and MLO3 and the defense-related secreted proteins GLP and PR5;(5) The expression patterns of 16 genes were further illuminated by RT-qPCR. The present study identified several candidate genes and pathways that may contribute to PM resistance in grapes and illustrated that RNA-seq is a powerful tool for studying gene expression. The RT-qPCR results reveal that effective resistance responses of grapes to PM include enhancement of JA and SAR responses and accumulation of phytoalexins.