Transcriptome Analysis of Berries of Spine Grape (Vitis davidii Föex) Infected by Colletotrichum viniferum during Symptom Development

Abstract

Grape ripe rot (Colletotrichum viniferum) causes huge losses in grape production in vineyards in southern China. However, the molecular mechanism against ripe rot in grape species and the responsive genes implicated in these processes are relatively unknown. Here, we present the transcriptome analysis of berries from a C. viniferum-resistant species (Vitis davidii Föex). Uninfected berries at day zero were used as control samples (CK), an inoculation was made at day zero, and the berries were subsequently analyzed at 1 day, 3 days, and 7 days post inoculation (dpi), which exhibited a sequential disease-progression stage. There were a total of 1810 differentially expressed genes, including 1315 up-regulated and 495 down-regulated transcripts. At 7 dpi, these differentially expressed genes (DEGs) were predominantly enriched in berries. In addition, in C. viniferum-infected grape fruits at 7 dpi, considerable changes in gene expression were induced, and those up-regulated genes involved in MAPK cascade, calcium ion binding, and serine/threonine kinase activity were enriched. According to our KEGG pathway analysis, numerous enriched biological processes, such as plant–pathogen interaction, phenylpropanoid biosynthesis, and metabolism, were implicated in grape–fungus interactions. Our research also revealed alterations in the expression pattern of phenylalanine-pathway-related transcription factors (TFs) and genes. We proposed a model in which C. viniferum invasion produces intracellular and extracellular Ca2+ deregulation to stimulate the MAPK pathway to activate TFs’ (WRKY, ERF, and MYB) up-regulation, thus initiating disease-resistant responses in the tolerant Vitis species. Our results offer comprehensive transcriptomic data about molecular responses in C. viniferum-infected grape, and these data will aid in understanding of processes underlying plant responses to C. viniferum.