Center for Viticulture and Enology, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China.
Key Laboratory of Viticulture and Enology, Ministry of Agriculture and Rural Affairs, Beijing 100083, China.
Genes (Basel). 2020 Sep 30;11(10):1156. doi: 10.3390/genes11101156.
To investigate the effect of light intensity on flavonoid biosynthesis, grapevine calluses were subjected to high light (HL, 250 μmol m s) and dark (0 μmol m s) in comparison to 125 μmol m s under controlled conditions (NL). The alteration of flavonoid profiles was determined and was integrated with RNA sequencing (RNA-seq)-based transcriptional changes of the flavonoid pathway genes. Results revealed that dark conditions inhibited flavonoid biosynthesis. Increasing light intensity affected flavonoids differently-the concentrations of flavonols and anthocyanins as well as the expressions of corresponding genes were less affected, whereas flavan-3-ol concentrations were predominantly increased, which caused enhanced -flavan-3-ol concentrations. Moreover, genes encoding leucoanthocyanidin reductase (LAR) exhibited different response patterns to light intensity changes- expression increased with an increased light intensity, whereas expression was insensitive. We further confirmed that the known transcription factors (TFs) involved in regulating flavan-3-ol biosynthesis utilized as a target gene in grapevine calluses. In addition, promoter activity was more sensitive to light intensity changes than that of as determined using a transgenic Arabidopsis leaf system. These results suggested that light intensity had the most prominent effect on -flavan-3-ols in grapevine calluses and demonstrated that the two LAR genes had different response patterns to light intensity changes.
为了研究光强对类黄酮生物合成的影响，将葡萄愈伤组织置于高光（HL，250 μmol m s）和黑暗（0 μmol m s）下，并与 125 μmol m s 的控制条件（NL）进行比较。测定了类黄酮图谱的变化，并与基于 RNA 测序（RNA-seq）的类黄酮途径基因转录变化进行了整合。结果表明，黑暗条件抑制了类黄酮的生物合成。增加光强对类黄酮的影响不同——黄酮醇和花色苷的浓度以及相应基因的表达受影响较小，而黄烷-3-醇的浓度则主要增加，导致 -flavan-3-ol 浓度升高。此外，编码无色花青素还原酶（LAR）的基因对光强变化表现出不同的反应模式——表达随光强增加而增加，而 表达不敏感。我们进一步证实，参与调控黄烷-3-醇生物合成的已知转录因子（TFs）在葡萄愈伤组织中以 作为靶基因。此外，通过转基因拟南芥叶片系统，发现 启动子活性对光强变化比 更敏感。这些结果表明，光强对葡萄愈伤组织中的 -flavan-3-ols 影响最大，并表明两个 LAR 基因对光强变化的反应模式不同。
