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The Gibberellic Acid-stimulated Arabidopsis (GASA) gene family is involved in the regulation of gene expression and plant growth, development, and stress responses. To investigate the function of loquat GASA genes in the growth and developmental regulation of plants, a loquat EjGASA6 gene homologous to Arabidopsis AtGASA6 was cloned. EjGASA6 expression was induced by gibberellin, and ectopic transgenic plants containing this gene exhibited earlier bloom and longer primary roots since these phenotypic characteristics are related to higher gibberellin content. Transcriptome analysis and qRT-PCR results showed that the expression levels of GA3ox1 and GA20ox1, which encode key enzymes in gibberellin biosynthesis, were significantly increased. Furthermore, we confirmed that EjGASA6 could promote the expression of GA20ox1 via the luciferase reporter system. Overall, our results suggest that EjGASA6 promotes blooming and main-root elongation by positively regulating gibberellin biosynthesis. These findings broaden our understanding of the role of GASAs in plant development and growth, and lay the groundwork for future research into the functions of EjGASA6 in regulating loquat growth and development.

Triploid loquats are divided into yellow- and white-fleshed cultivars. To better understand taste variations in triploid loquat fruits, we used a UPLC-ESI-QTRAP-MS/MS-based widely targeted metabolomic analysis to examine the metabolic composition of two different color fleshed triploid loquats with a sample size of 54 and external validation method within a confidence level of P＜0.05. We identified key flavor-related differentially accumulated metabolites using the variable importance in projection (VIP) value (VIP ≥ 1.0) and fold change ≥ 2 or ≤ 0.5. Furthermore, the results of the HPLC analysis showed that white-fleshed loquats had a low malic acid content. We also performed the UPLC-MS/MS system to investigate the carotenoids contents and lipidome in four triploid cultivars. In the fruits of white-fleshed varieties, the carotenoids contents were significantly downregulated, but the contents of most glycerolphospholipids were increased. Our results reveal the metabolomic changes between the yellow- and white-fleshed cultivars.

The protective effects of the topical application of orange peel cold-pressed oil (CPO), a rich polymethoxyflavones (PMFs) source, on ultraviolet B (UVB)-induced skin injury were studied. Depilated KM mice were irradiated by UVB at one minimal erythemal dose every day and the treated groups were smeared with CPO before radiation. After two weeks we found that CPO helped to maintain the dermal structure and enhanced serum levels and skin tissue expression of superoxide dismutase, catalase and glutathione peroxidase. In serum CPO lowered interleukin-6/-1β and tumor necrosis factor α levels; in skin it decreased the levels of type III collagen and H2O2 but increased hydroxyproline and type I collagen. Moreover, the skin expression of matrix metalloproteinases 2/9 was downregulated, whereas the expression of tissue inhibitor of metalloproteinases 1/2 was upregulated. The above effects followed a dose-dependent manner. Liquid chromatography analysis of irradiated skin tissue showed partial decomposition of PMFs into 5-hydroxy-PMFs.