P-156 - Dual-RNAseq reveals insights into the suspectible infection of highbush blueberry (Vaccinium corymbosum) fruits by anthracnose pathogen Colletotrichum fioriniae

Blueberry anthracnose is an important post-harvest fruit rot caused by Colletotrichum species such as C. fioriniae. This study aimed to examine the mechanisms of the infection of blueberry (Vaccinium corymbosum) fruits by C. fioriniae from both the plant and pathogen perspective. Ripe fruits (cv. 'Jersey') were inoculated with a spore suspension of C. fioriniae or a mock inoculation of sterile deionized water and incubated in humidity chambers for up to 14 days. Inoculated fruits were sampled daily at 0 to 7 days post inoculation (dpi) and at 14dpi. Each sample had a cDNA library generated from RNA extractions that were then sequenced. Quality-filtered reads had adapters removed before mapping to reference genomes for V. corymbosum and C. fioriniae. Aligned transcripts were quantified and differential expression analysis was performed with edgeR. Expression patterns in C. fioriniae indicate transcriptional changes at 12hpi, 1dpi, 5dpi, and 14dpi. 599 secreted carbohydrate active enzymes were identified to be expressed during infection. In V. corymbosum, even at 0 dpi transcripts encoding defense related protein products were upregulated in inoculated fruits. Transcripts encoding proteins related to programmed cell death and processing flavonoids were upregulated as soon as 12hpi. These data provide insights into anthracnose resistance that are informative to plant breeding initiatives and exploration of the molecular mechanisms of C. fioriniae infection in blueberry.