Differential Anthocyanin Concentrations and Expression of Anthocyanin Biosynthesis Genes in Strawberry ‘Sachinoka’ during Fruit Ripening under High-temperature Stress

抄録

We investigated anthocyanin concentration and the expression of anthocyanin biosynthesis related genes in strawberry ‘Sachinoka’ (Fragaria×ananassa Duch.) grown at control regime (20/15°C, 14/10 h, day/night) or high temperature regime (30/15°C, 14/10 h). In Experiment 1, fruits were harvested at different color stages. In the control treatment, the anthocyanin concentration increased as fruit ripened, and was highest at the fully ripe stage. In the high-temperature treatment, however, it was significantly lower at the fully ripe stage. These results were relevant with the peak value of expression of anthocyanin biosynthesis genes which was inhibited in fruits grow at high temperature regime. In Experiment 2, we applied high temperature at different fruit color stages to test the effect of the timing of high temperature stress on coloring. When exposed fruit to high temperature after half ripe stage, the anthocyanin concentration and gene expression in fully ripe fruit were not significantly different from the control. But in fruit exposed before half ripe stage, the anthocyanin concentration and gene expression significantly reduced. These results indicate that the level of gene expression of anthocyanin biosynthesis is affected by the timing of exposure fruit to high temperature stress.