Comparative transcriptome analysis reveals key genes potentially related to soluble sugar and organic acid accumulation in watermelon

作者：Lei Gao, Shengjie Zhao, Xuqiang Lü, Nan He, Hongju Zhu, Junling Dou, Wenge Liu · 发表于：PLoS ONE · 年份：2018 · DOI：10.1371/journal.pone.0190096 · 被引用次数：69 · 研究领域：Plant nutrient uptake and metabolism、Advances in Cucurbitaceae Research、Microbial Metabolites in Food Biotechnology

Soluble sugars and organic acids are important components of fruit flavor and have a strong impact on the overall organoleptic quality of watermelon (Citrullus lanatus) fruit. Several studies have analyzed the expression levels of the genes related to soluble sugar accumulation and the dynamic changes in their content during watermelon fruit development and ripening. Nevertheless, to date, there have been no reports on the organic acid content in watermelon or the genes regulating their synthesis. In this study, the soluble sugars and organic acids in watermelon were measured and a comparative transcriptome analysis was performed to identify the key genes involved in the accumulation of these substances during fruit development and ripening. The watermelon cultivar '203Z' and its near-isogenic line (NIL) 'SW' (in the '203Z' background) were used as experimental materials. The results suggested that soluble sugar consist of fructose, glucose and sucrose while malic-, citric-, and oxalic acids are the primary organic acids in watermelon fruit. Several differentially expressed genes (DEGs) related to soluble sugar- and organic acid accumulation and metabolism were identified. These include the DEGs encoding raffinose synthase, sucrose synthase (SuSy), sucrose-phosphate synthase (SPSs), insoluble acid invertases (IAI), NAD-dependent malate dehydrogenase (NAD-cyt MDH), aluminum-activated malate transporter (ALMT), and citrate synthase (CS). This is the first report addressing comp...