Arabidopsis thaliana life without phytochromes
Arabidopsis thaliana life without phytochromes
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DOI：
10.1073/pnas.0910446107
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发表时间：
2010-03
期刊：
影响因子：
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通讯作者：
B. Strasser;M. Sánchez-Lamas;M. Yanovsky;J. Casal;P. Cerdán
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文献类型：
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作者：
B. Strasser;M. Sánchez-Lamas;M. Yanovsky;J. Casal;P. Cerdán
植物利用光作为光合作用的能量来源，并作为光感受器感知的环境信息的来源。测试植物是否可以完成其周期，如果光提供能量，但没有关于环境的信息，需要植物缺乏光敏色素，因为所有光合作用有效波长激活光敏色素。产生这样的拟南芥五倍体突变体具有挑战性，但我们能够在开花位点T（ft）突变体背景中获得它。五元光敏色素突变体在FT背景下不萌发，但在FT背景下有一定程度的萌发。如果发芽问题是通过添加赤霉素绕过，幼苗的五倍光敏色素突变体暴露于红光产生叶绿素，这表明光敏色素不是唯一的红光光感受器，但他们成为发育后不久，子叶阶段。蓝光绕过了这一障碍，否定了长期存在的观点，即蓝光受体隐花色素不能在没有光敏色素的情况下运作。在白色光下生长后，将五元光敏色素突变体返回红光导致已经展开的叶片迅速衰老，并严重损害新叶的展开。我们的结论是，拟南芥的发展是停滞在几个点的存在下，光适合光合作用，但没有提供光形态发生信号。
Plants use light as a source of energy for photosynthesis and as a source of environmental information perceived by photoreceptors. Testing whether plants can complete their cycle if light provides energy but no information about the environment requires a plant devoid of phytochromes because all photosynthetically active wavelengths activate phytochromes. Producing such a quintuple mutant of Arabidopsis thaliana has been challenging, but we were able to obtain it in the flowering locus T (ft) mutant background. The quintuple phytochrome mutant does not germinate in the FT background, but it germinates to some extent in the ft background. If germination problems are bypassed by the addition of gibberellins, the seedlings of the quintuple phytochrome mutant exposed to red light produce chlorophyll, indicating that phytochromes are not the sole red-light photoreceptors, but they become developmentally arrested shortly after the cotyledon stage. Blue light bypasses this blockage, rejecting the long-standing idea that the blue-light receptors cryptochromes cannot operate without phytochromes. After growth under white light, returning the quintuple phytochrome mutant to red light resulted in rapid senescence of already expanded leaves and severely impaired expansion of new leaves. We conclude that Arabidopsis development is stalled at several points in the presence of light suitable for photosynthesis but providing no photomorphogenic signal.