关键词: 苹果, 砧木, 锌胁迫, MTP, 实时荧光定量PCR, 富集系数, 转运系数

Abstract: To investigate the responses of zinc（Zn）accumulation，distribution and molecular level to high Zn stress，the experimental materials，Malus robusta Rehd. seedlings with eight leaves，were treated with different Zn concentrations（4，25，50，100 μmol ? L-1）by solution culture. The results showed that the excessive Zn stress seriously affected plant growth and the accumulation and distribution of Zn in apple seedlings. With the increase of Zn concentration，the content of Zn in roots was significantly higher than that in stems and leaves. The increase of bioaccumulation factor（BAF）and the decrease of translocation factor（TF）all indicated that Zn was accumulated in the roots to reduce the damage to the ground. According to the relative expression of 9 MTP genes，correlation analysis under high zinc stress，expression of MTP genes was closely associated with Zn content. The expression of MTP1 had tissue specificity that was significantly higher in stems and leaves than that in roots. The expression of MTPC2-like was significantly positively correlated with Zn content under the treatment of 4 μmol ? L-1 Zn，but the correlation decreased under the high concentration of Zn stress，which indicated that the expression of MTP gene had effects of concentration.

Key words: apple, rootstock, zinc stress, MTP, real-time quantitative PCR, bioaccumulation factor, translocation factor