干旱胁迫对山定子水分生理及AQPs表达的影响

Effects of drought stress on water physiology and AQPs expression of Malus baccata

【目的】研究干旱胁迫对山定子水分生理及AQPs表达水平的影响.【方法】2年生山定子盆栽苗,设置对照、轻度干旱胁迫、中度干旱胁迫和重度干旱胁迫4个试验处理.【结果】山定子叶片水势、叶片含水量、自由水、叶片相对含水量和茎、根系组织含水随干旱胁迫程度的加重而显著降低,束缚水含量及饱和亏则显著增加,复水后各水分生理呈恢复趋势.干旱胁迫影响AQPs的表达,MdPIP2;4,MdNIP4;2和MdNIP6;1在山定子叶片中随干旱胁迫程度的变化其表达量均上调,MdPIP1;4在叶片中未表达,其他AQPs均呈下调趋势.AQPs在山定子根中全部表达,其中MdNIP4;1,MdTIP1;3,MdTIP2;2和MdTIP5;1在山定子根部随胁迫程度的变化其表达量均上调,MdNIP2;2和Mdδ-TIP表达量下调.【结论】干旱胁迫能够显著影响山定子叶片含水量、自由水、叶片水势等水分生理的变化,基质水分与各水分生理呈相关或显著相关性.AQPs的表达受干旱胁迫的显著影响,在山定子叶片和根部的表达存在组织差异性,主要表现为AQPs表达量的显著差异.

To understand the effects of drought stress on water physiology and AQPs expression of Malus baccata. [Method] Two years old potted seedlings were used as materials. The treatments were designed as the control,mild,moderate and severe drought stress. [Result] The leaf water potential, leaf water content, free water, relative water content of leaves and stem and root tissue water content were significantly decreased with the increase of drought stress, while the bound water content and saturation deficit were significantly increased, and the water physiological tended to recover after rewatering. The expression of MdPIP2; 4 ,MdNIP4;2 and MdNIP6;1 were up regulated in the leaves,MdPIP1;4 was not expressed in the leaves, and the other AQPs were down regulated. The expression levels of MdNIP4 ; 1,MdTIP1 ; 3 ,MdTIP2 ; 2 and MdTIP5 ; 1 in the roots were all up regulated, and the expression levels of MdNIP2; 2 and Mdδ-TIP were down-regulated. [Conclusions] Drought stress significantly affect the changes of water physiology of the M. baccata, and there is a significant correlation between matrix moisture and each water physiology. The expression of AQPs is significantly affected by drought stress, and there is a significant difference in the expression of AQPs in leaves and roots.