Analysis of different pigmentation patterns in ‘Mantianhong’ (Pyrus pyrifolia Nakai) and ‘Cascade’ (Pyrus communis L.) under bagging treatment and postharvest UV-B/visible irradiation conditions

The pigmentation patterns of ‘Mantianhong’ (Pyrus pyrifolia Nakai) and ‘Cascade’ (Pyrus communis L.) that develop under bagging and postharvest UV-B/visible irradiation conditions were evaluated in this study. The results showed that, unlike ‘Cascade,’ in which almost no anthocyanin was detected, ‘Mantianhong’ developed good red coloration under bagging treatment and postharvest irradiation. The activity of PAL and DFR increased during anthocyanin accumulation. The expression of PpCHS3, PpCHI3, PpUFGT1, and PyMYB10 was up-regulated in ‘Mantianhong’ but not in ‘Cascade’ during both treatments. This suggests that these four genes may be limiting factors for peel coloration in ‘Cascade.’ The expression patterns of gene family members were also different during fruit red coloration, suggesting that different gene family members may have distinct functions during pear development. The results obtained in this study are helpful in understanding the molecular mechanism of anthocyanin accumulation in red pears and can serve as the basis for the development of marker-assisted selection or for anthocyanin metabolic engineering of pears.

► Two treatments enhanced anthocyanin content in ‘Mantianhong’ (Pyruspyrifolia). ► Two treatments scarcely promotedanthocyanin synthesisin ‘Cascade’ (P.communis). ► Expression of PpCHS3, PpCHI3, PpUFGT1, and PyMYB10 wasup-regulated in ‘Mantianhong’. ► Expression of genes was different among family members during two treatments.