Effects of preharvest UV-B irradiation on anthocyanin biosynthesis in blueberry

L. Taishan, H. Yamane, R. Tao
The effects of preharvest UV irradiation on blueberry fruit development were investigated to explore the potential use of UV irradiation in blueberry production systems. Long-term UV-B treatments with environment-dependent dosing were applied to southern highbush blueberry (Vaccinium corymbosum interspecific hybrid), 'O'Neal' trees in a greenhouse, during the entire reproductive period. The experimental treatments included UV irradiation conditions representing an average winter day (low, 0.07 W m‑2), an average summer day (medium, 0.14 W m‑2) and 30% above that of an average summer day (high, 0.19 W m‑2). Compared with the control, the total anthocyanin content increased by 167 and 148% after the application of medium- and high-dose UV, respectively. Gene expression changes of anthocyanin biosynthesis-related structure genes, the MYB transcription factor, a UV receptor, and light-responsive genes were examined and different responses under different UV-B exposures were identified. Simultaneous upregulation of the MYB transcription factor, VcMYBPA1, with biosynthesis-related structure genes (such as VcCHS and VcDFR) in response to low- and high-dose UV-B suggests that VcMYBPA1 may increase biosynthesis-related gene expression, thereby enhancing anthocyanin accumulation in fruits in response to UV-B. The results demonstrate the possible use of UV-B irradiation at doses of 0.14 and 0.19 W m‑2 to improve blueberry anthocyanin accumulation.
Taishan, L., Yamane, H. and Tao, R. (2021). Effects of preharvest UV-B irradiation on anthocyanin biosynthesis in blueberry. Acta Hortic. 1312, 139-144
DOI: 10.17660/ActaHortic.2021.1312.21
anthocyanin, blueberry, fruit maturation, MYB, UV-B

Acta Horticulturae