Studies on fruit coloration and expression of anthocyanin biosynthesis genes in mango cultivar 'Tainong No. 1' under different ecological conditions.
Wu HongXia, Ma XiaoWei, Wang SongBiao, Xu WenTian, Luo Chun, Yao QuanSheng, Zhan RuLin, Gao ZhongShan
Author Affiliation: College of Agriculture and Biotechnology, Zhejiang University, Hangzhou 310058, Zhejiang, China.
Journal of Fruit Science 33 : 16-23
Abstract : Studies were conducted to evaluate the impacts of ecological conditions on the coloration of mango cv. Tainong No.1 fruits, pigment concentrations and the expressions of genes involved in anthocyanins synthesis in the pericarp of mango sampled in Panzhihua, Sichuan province and in Leizhou, Guangdong province (China). Climacteric data, including temperature (the highest, lowest and diurnal temperature differences) and rain were collected. Levels of chlorophylls, caroteniods and flavonoids in the pericarp were measured by traditional methods. Total RNA was extracted using the CTAB method, first-strand cDNA was synthesized, primer pairs were designed and the relative expression levels of the target genes were calculated. The results showed that Panzhihua had higher altitudes, average daily highest temperature, average lowest temperature and diurnal temperature differences, but lower rain than Leizhou. With regard to pericarp pigments, the contents of chrolorophylls and carotenoids in fruit sampled in Panzhihua were significantly higher, while the content of flavonoids was lower than in fruit taken in Leizhou. The concentration of anthocyanins in mango sampled in Panzhihua reached 30.5 mg/kg, while they were not detected in samples from Leizhou. There was no significant difference in lightness and chrome in the pericarp between samples taken in Panzhihua and Leizhou, but the hue angle in fruit from Leizhou was higher than in those from Panzhihua. The expressions of anthocyanin synthesis genes showed significant difference in fruit produced in the 2 regions. The expression levels of genes involved in anthocyanin synthesis, especially MiPAL, MiC4H, MiCHS1, MiF3H1, MiDFR and MiUFGT, were significantly higher in fruit from Panzhihua than those from Leizhou, and the expression levels of MiC4H, MiCHS1, and MIF3H1, MiDFR and MiUFGT in fruit from Panzhihua were over 130, 228, 63, 2.7 and 4.3 times higher than those from Leizhou, respectively.