Abscisic acid-induced changes in inositol metabolism in Spirodela polyrrhiza
Abscisic acid-induced changes in inositol metabolism in Spirodela polyrrhiza
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DOI：
10.1007/s004250000348
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发表时间：
2000-11-01
期刊：
影响因子：
4.3
通讯作者：
Smart, CC
中科院分区：
文献类型：
--
作者：
Flores, S;Smart, CC
在脱落酸(ABA)刺激下，紫萍Spirodela PolyrRha(L.)激活一条发育途径，最终形成休眠结构，也就是所谓的大葱。将葡萄糖-6-磷酸转化为肌醇-3-磷酸的D-肌醇-3-磷酸合成酶(EC.5.5.1.4)的mRNA水平在ABA处理后早期升高，为了了解该酶在Turion形成中的作用，我们研究了ABA处理植物中肌醇代谢的变化。在这里，我们表明，ABA处理导致3倍的游离肌醇增加。治疗后2d达高峰。这种增加之后是肌醇磷酸盐的连续增加，特别是肌醇六磷酸(INSP(6))的积累。此外，我们观察到一种新的肌醇二磷酸的早期增加，它不是直接在通往INSP的途径上(6)。在对照植物中，我们观察到五磷酸肌醇和Insp(6)的合成和周转。在ABA处理和对照植物中都存在比Insp(6)(二磷肌醇多磷酸)更极性的两种化合物。综上所述，这表明Insp(6)在植物中的作用可能比休眠期间简单的储存化合物更复杂。
In response to abscisic acid (ABA), the duckweed Spirodela polyrrhiza (L.) activates a developmental pathway that culminates in the formation of dormant structures known as turions. Levels of the mRNA encoding D-myo-inositol-3-phosphate synthase (EC.5.5.1.4) which converts glucose-6-phosphate to inositol-3-phosphate, increase early in response to ABA, In order to understand the role of this enzyme in turion formation, we have investigated changes in inositol metabolism in ABA-treated plants. Here, we show that ABA-treatment leads to a 3-fold increase in free inositol. which peaks 2 d after treatment. This increase is followed by sequential increases in inositol phosphates and in accumulation of inositol hexakisphosphate (InsP(6)), in particular. In addition, we observed an early increase in a novel inositol bisphosphate which is not directly on the pathway to InsP(6). In control plants, we observed synthesis and turnover of both inositol pentakisphosphate and InsP(6). Two compounds more polar than InsP(6) (diphosphoinositol polyphosphates were present in both ABA-treated and control plants. Together, this suggests that the role of InsP(6) in plants may be more complex than simply that of a storage compound during dormancy.