High anthocyanin accumulation in an Arabidopsis mutant defective in chloroplast biogenesis

Abstract

Anthocyanin has an important antioxidant protective effect on plant resistance to oxidative stress. In this study, an Arabidopsis mutant dpg1 (delayed pale-greening) with a chloroplast development defect was studied. It was found that the anthocyanin accumulation of this mutant had increased during the seedling stage, and the expressions of the anthocyanin biosynthetic and regulatory genes were up-regulated. Further studies showed that exogenous ABA (abscisic acid) treatments significantly promoted the chloroplast development of the dpg1 mutant, and the anthocyanin content was significantly decreased to the level of the wild-type. When using NF (norflurazon) to simulate the oxidative stress treatments of wild-type Arabidopsis, the anthocyanin content had significantly increased compared with the control. However, the exogenous ABA treatments could significantly reduce the anthocyanin accumulation level induced by the oxidative stress. Furthermore, the components ABI1 (abscisic acid insensitive 1) and ABI3 (abscisic acid insensitive 3) of the ABA signaling pathway were found to play important roles during this process. These results indicate that the increases in the anthocyanin accumulation in the dpg1 mutant seedlings could be mediated by oxidative stress. Meanwhile, the ABI1 and ABI3 were involved in the process of the ABA inhibiting anthocyanin accumulation which had been induced by the oxidative stress.