Expression of expansin gene, MiExpA1, and activity of galactosidase and polygalacturonase in mango fruit as affected by oxalic acid during storage at room temperature.
Zheng XiaoLin, Jing GuoXing, Liu Yan, Jiang TianJia, Jiang YueMing, Li JianRong
Author Affiliation: College of Food Science and Biotechnology, Zhejiang Gongshang University, Food Safety Key Lab of Zhejiang Province, Hangzhou 310035, China.
Food Chemistry 132 : 849-854
Abstract : An expansin gene, MiExpA1, from mango fruit (Mangifera indica L. cv. Zill), which had highest homology with MiExpA1 from cv. Dashehari by 96.43% in nucleotide sequence and 95.79% in amino acid sequence, was cloned and characterised. Moreover, effects of oxalic acid on MiExpA1 expression and enzymatic activities of ?-galactosidase (?-Gal), ?-galactosidase (?-Gal), and polygalacturonase (PG) were investigated after Zill fruit were dipped in 5 mM oxalic acid solution for 10 min and then stored at 25°C. Application of oxalic acid significantly inhibited decrease in flesh firmness, notably suppressed and delayed MiExpA1 expression in the peel and the flesh, and also significantly decreased activities of these pectolytic enzymes in the flesh. It was suggested that these effects of oxalic acid might collectively contribute to alleviating cell wall disassembly, thereby slowing the process of softening and ripening in mango fruit during storage.