关键词: 苹果, MdMYB2, ABA, 干旱, 低温

Abstract: In order to elucidate the biological function of the R2R3-MYB transcription factor gene MdMYB2 of apple（Malus × domestica） under abiotic stress conditions，the promoter sequence of MdMYB2 was analyzed. It was found that the promoter sequence of MdMYB2 contained abscisic acid（ABA），defense，stress，and low-temperature related cis-acting elements，and the expression of MdMYB2 was regulated by exogenous ABA，polyethyleneglycol（PEG），and 4 ℃ treatments. For the MdMYB2-OE Arabidopsis plants and MdMYB2-OE apple calli，it was found that the application of ABA severely inhibited the germination of MdMYB2-OE Arabidopsis，while increased its ABA sensitivity，drought and cold tolerance. At the same time，MdMYB2-OE apple calli also showed sensitivity to exogenous ABA，as well as drought and cold tolerance. Overall，the above results indicated that MdMYB2 played an important role in the abiotic stress response of plants.

Key words: apple, MdMYB2, ABA, drought, low temperature