Loquat ( Eriobotrya japonica ) is rich in flavonols with health-promoting functions. However, regulatory mechanisms of flavonol biosynthesis in loquat are unclear. This study functionally characterized an R2R3-MYB, EjMYBF1 from loquat. Expression level of EjMYBF1 is positively correlated with flavonol content at different stages of fruit development and in ten accessions with differential flavonol accumulation. Dual-luciferase assays and EMSA indicated that EjMYBF1 transactivated the promoters of structural genes involved in flavonol biosynthesis by binding to promoter regions containing MYBCORE elements. Transient overexpression and virus-induced gene silencing assays of EjMYBF1 in loquat fruit peels and leaves, as well as heterologous constitutive expression of EjMYBF1 in Nicotiana tabacum confirmed that EjMYBF1 is a positive regulator of flavonol biosynthesis in loquat. These results demonstrate that EjMYBF1 is a functional flavonol-specific activator in loquat and explain one reason for its high flavonol content from the perspective of transcriptional regulation. This work provides a potential target for improving loquat nutrition and for applications in secondary metabolic engineering.
Crocus sativus L. is a both medicinal and food bulbous flower whose qualities are geographically characterized. However, identification involving different places of origin of such substances is currently limited to single-omics mediated content analysis. Integrated metabolomics and proteomics, 840 saffron samples from six countries (Spain, Greece, Iran, China, Japan, and India) were analyzed using the QuEChERS extraction method. A total of 77 differential metabolites and 14 differential proteins were identified. The limits of detection of the method were 1.33 to 8.33 μg kg −1 , and the recoveries were 85.56% to 105.18%. Using homology modeling and molecular docking, the Gln84, Lys195, Val182 and Pro184 sites of Crocetin glucosyltransferase 2 were found to be the targets of crocetin binding. By multivariate statistical analysis (PCA and PLS-DA), different saffron samples were clearly distinguished. The results provided the basis for the selection and identification of high quality saffron from different producing areas.
危险品化学品经营许可证（带存储）