The Innovation and Application Engineering Technology Research Center of Ornamental Plant Germplasm Resources in Fujian Province, National Long term Scientific Research Base for Fujian Orchid Conservation, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.
Department of Forest and Conservation Sciences, Faculty of Forestry, The University of British Columbia, Vancouver, BC, Canada.
BMC Plant Biol. 2024 Oct 10;24(1):943. doi: 10.1186/s12870-024-05621-4.
The sugar and organic acid content significantly impacts the flavor quality of star fruit, and it undergoes dynamic changes during development. However, the metabolic network and molecular mechanisms governing the formation of sugar and organic acid in star fruit remain unclear. In this study, 23 of 743 components were detected by metabonomic analysis. The highest metabolites contents were organic acids and derivatives. The highest sugar content in the fruit was fructose and glucose, followed by sucrose, which proved that A. carambola is a hexose accumulation type fruit. Genome identification preliminarily screened 141 genes related to glucose metabolism and 67 genes related to acid metabolism. A total of 7,881 unigenes were found in transcriptome data, 6,124 differentially expressed genes were screened, with more up-regulated than down-regulated genes. Transcriptome and metabolome association analysis screened seven core candidate genes related to glucose metabolism and 17 core genes highly related to organic acid pathway, and eight differentially expressed sugar and acid genes were selected for qRT-PCR verification. In addition, 29 bHLHs and eight bZIPs transcription factors were predicted in the glucose metabolism pathway, and 23 MYBs, nine C2H2s transcription factors and one GRAS transcription factor was predicted in the acid metabolism pathway, and transcription factors have both positive and negative regulatory effects on sugar and acid structure genes. This study increased our understanding of A. carambola fruit flavor and provided basic information for further exploring the ornamental and edible values of star fruit.
糖和有机酸含量对杨桃风味品质有显著影响，且在发育过程中发生动态变化。然而，糖和有机酸在杨桃中形成的代谢网络和分子机制尚不清楚。本研究通过代谢组学分析检测到 743 种成分中的 23 种。含量最高的代谢物为有机酸及其衍生物。果实中含量最高的糖为果糖和葡萄糖，其次是蔗糖，这证明杨桃是一种己糖积累型果实。基因组鉴定初步筛选出与葡萄糖代谢相关的 141 个基因和与酸代谢相关的 67 个基因。在转录组数据中发现了 7881 条 unigenes，筛选出 6124 个差异表达基因，上调基因多于下调基因。转录组和代谢组关联分析筛选出与葡萄糖代谢相关的 7 个核心候选基因和与有机酸途径高度相关的 17 个核心基因，并选择 8 个差异表达的糖和酸基因进行 qRT-PCR 验证。此外，在葡萄糖代谢途径中预测到 29 个 bHLHs 和 8 个 bZIPs 转录因子，在酸代谢途径中预测到 23 个 MYBs、9 个 C2H2s 转录因子和 1 个 GRAS 转录因子，转录因子对糖和酸结构基因既有正调控作用，也有负调控作用。本研究加深了我们对杨桃果实风味的理解，为进一步探索杨桃的观赏和食用价值提供了基础信息。
