Selection of differentially expressed genes using the transcriptome analysis of ripening grape berries in response to high temperature

Abstract

Purpose: The transcriptome of ‘Campbell Early’grape berries exposed to high temperature was analyzed to select useful genes by evaluating their differential expression through sequencing short reads on Solexa platform. Research Method: We assembled 118 million high-quality trimmed reads using Velvet followed by Oases. Findings: Functional categorization of expressed transcripts revealed the conservation of genes involved in various biological processes like responses to chemical (12.7%), responses to abiotic stimulus (11.8%), biosynthesis processes (11.8%), and cellular metabolic processes (10.4%) in grape berries exposed to high temperature. The major up-regulated genes included isocitratelyase, cysteine proteinoses superfamily protein, cupin family protein, and glycosyl hydrolase genes, and the major down-regulated genes included flavanone 3-hydroxylase, phenylalanine ammonia lyase, chlorophyll A-B binding family protein, and polygalacturonase inhibiting protein genes in grape berries exposed to high temperature. Among genes related to grape coloration, expressions of chalcone and stilbene synthase, flavanone 3-hydroxylase, leucoanthocyanidin dioxygenase, phenylalanine ammonia lyasegenes were more strongly inhibited in berries kept at 35°C than 25°C. Originality/Value: Transcript sets of grape berries generated in this study will provide a resource for gene discovery and development of functional molecular markers to be used in elucidating the mechanism of tolerance to high temperature.