Activation of abscisic acid biosynthesis in the leaves of Arabidopsis thaliana in response to water deficit
Activation of abscisic acid biosynthesis in the leaves of Arabidopsis thaliana in response to water deficit
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DOI：
10.1007/s10265-008-0201-9
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发表时间：
2009-03-01
影响因子：
2.8
通讯作者：
Koshiba, Tomokazu
中科院分区：
文献类型：
--
作者：
Ikegami, Keiichi;Okamoto, Masanori;Koshiba, Tomokazu
众所周知，内源脱落酸（ABA）水平在干旱胁迫下迅速增加，从而导致气孔关闭。拟南芥（Arabidopsis thaliana）在干旱胁迫下，叶片和根部的ABA水平迅速升高。而当叶片和根系分开单独处理时，ABA含量仅在叶片中增加。这些结果表明，在我们的实验条件下，ABA主要在叶片中合成以应对干旱胁迫，并且叶片中积累的部分ABA被转运到根中。利用同位素标记的ABA示踪实验表明，ABA从叶片向根系的运动受到根系水分亏缺的激活。我们还证明，只有当叶片自身暴露于干旱胁迫时，叶片中的内源ABA水平才会增加，这表明叶片在应对急性缺水的ABA生产中起主要作用。
It is well known that endogenous abscisic acid (ABA) levels increase rapidly in response to drought stress and that this induces stomatal closure. In Arabidopsis thaliana, ABA levels increased rapidly in the leaves and roots when intact wild-type whole plants were exposed to drought stress. However, if the leaves and roots were separated and exposed to drought independently, the ABA level increased only in the leaves. These results suggest that, under our experimental conditions, ABA is synthesized mainly in the leaves in response to drought stress and that some of the ABA accumulated in the leaves is transported to the roots. Tracer experiments using isotope-labeled ABA indicate that the movement of ABA from leaves to roots is activated by water deficit in the roots. We also demonstrate that the endogenous ABA level in the leaves increased only when the leaves themselves were exposed to drought stress, suggesting that leaves play a major role in the production of ABA in response to acute water shortage.