The phytochrome-interacting transcription factor, PIF3, acts early, selectively, and positively in light-induced chloroplast development
The phytochrome-interacting transcription factor, PIF3, acts early, selectively, and positively in light-induced chloroplast development
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DOI：
10.1073/pnas.0407107101
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发表时间：
2004-11-16
影响因子：
11.1
通讯作者：
Quail, PH
中科院分区：
文献类型：
--
作者：
Monte, E;Tepperman, JM;Quail, PH
光敏色素（phy）家族的感觉光感受器将信息光信号传递给选定的核基因，诱导植物生长和发育对环境的反应。现有的数据表明，其中一个信号通路，这涉及直接的，核内相互作用的光活化的phy分子与PIF 3，一个基本的螺旋-环-螺旋转录因子。在这里，我们提供的证据，从最近确定的pif 3突变等位基因，PIF 3是必要的早期叶绿体绿化和快速phy诱导的表达的核基因编码的叶绿体组件后，第一次曝光的幼苗。因此，这些数据表明，PIF 3的功能是向参与早期幼苗去黄化过程的关键方面（功能性光合机构的产生）的基因发出光合信号。当使用转基因表达的GUS：PIF 3融合蛋白构建体时，我们发现PIF 3蛋白水平在拟南芥幼苗的昼夜周期中被感光体快速且可逆地调节。PIF 3蛋白在初始光照后迅速下降至基础稳态水平，但在随后的夜间黑暗中重新积累至照射前水平。这些数据表明，PIF 3可能在黑暗到光明的过渡，不仅在初始幼苗脱黄化，但每天在黎明的昼夜光暗周期的早期物理信号。
The phytochrome (phy) family of sensory photoreceptors transduce informational light signals to selected nuclear genes, inducing plant growth and developmental responses appropriate to the environment. Existing data suggest that one signaling pathway by which this occurs involves direct, intranuclear interaction of the photoactivated phy molecule with PIF3, a basic helix-loop-helix transcription factor. Here, we provide evidence from recently identified pif3 mutant alleles that PIF3 is necessary for early chloroplast greening and rapid phy-induced expression of nuclear genes encoding chloroplast components upon first exposure of seedlings to light. Therefore, these data indicate that PIF3 functions to transduce phy signals to genes involved in a critical facet of the early seedling deetiolation process, the generation of a functional photosynthetic apparatus. When transgenically expressed GUS:PIF3 fusion protein constructs were used, we found that PIF3 protein levels are rapidly and reversibly modulated by the photoreceptor over diurnal cycles in Arabidopsis seedlings. The PIF3 protein declines rapidly to a basal steady-state level upon initial light exposure, but reaccumulates to preirradiation levels in darkness during the subsequent night period. These data suggest that PIF3 may function in early phy signaling at the dark-to-light transition, not only during initial seedling deetiolation, but daily at dawn under diurnal light-dark cycles.