Arabidopsis cue mutants with defective plastids are impaired primarily in the photocontrol of expression of photosynthesis-associated nuclear genes
Arabidopsis cue mutants with defective plastids are impaired primarily in the photocontrol of expression of photosynthesis-associated nuclear genes
复制标题
具有缺陷质体的拟南芥线索突变体主要在光合作用相关核基因表达的光控制方面受到损害
作者：
G. Vinti;N. Fourrier;J. Bowyer;E. López
植物光感受器检测光信号并启动从叶绿体分化到控制形态建成和开花的反应。光合作用相关的核基因的光控制出现密切相关的“逆行质体信号”，细胞器的状态控制核基因的表达。然而，什么样的具体作用，如果有的话，质体起源的信号在光响应中发挥的作用知之甚少：它在过去已经提出，质体信号在所有的响应“高通量”远红光感知的光不稳定光敏色素A，不管它们是否涉及光合作用相关的基因。为了进一步探讨这一点，我们重新研究了三个线索（cab-低表达）拟南芥突变体，叶绿体发育缺陷的表型。突变体具有不发达的病原体，其中cue 6、cue 8和cue 3的损伤增加。在长时间的远红光或红光下，突变体下胚轴伸长和子叶张开的光控制只有很小的缺陷，而在蓝光下，突变体的光控制正常。另一方面，光合相关的核基因的表达在黑暗中和红光或远红光短处理或连续光下的突变体中比那些与光合作用无关的光敏色素依赖基因的表达受到更大的损害。此外，红/远红光可逆反应涉及光合相关基因（诱导Lhcb 1-cab启动子活性，和光可逆程度的绿化）介导的光敏色素B和其他光稳定光敏色素，都显示出减少的线索突变体，这与致病体缺陷。我们的证据表明，质体来源的信号需要操作，以光敏色素控制光合核基因发生。
Plant photoreceptors detect light cues and initiate responses ranging from chloroplast differentiation to the control of morphogenesis and flowering. The photocontrol of photosynthesis-related nuclear genes appears closely related to ‘retrograde plastid signals’ by which the status of the organelle controls the expression of nuclear genes. However, what specific role, if any, plastid-originated signals play in light responses is poorly understood: it has in the past been proposed that plastid signals play a role in all responses to ‘high fluence’ far-red light perceived by the light-labile phytochrome A, irrespective of whether they involve photosynthesis-related genes. To explore this further, we have re-examined the phenotype of three cue (cab-underexpressed) Arabidopsis mutants, defective in chloroplast development. The mutants have underdeveloped etioplasts, with increasing impairments in cue6, cue8 and cue3. The mutants show only small defects in photocontrol of hypocotyl elongation and cotyledon opening under prolonged far-red or red light, and normal photocontrol under blue. On the other hand, the expression of photosynthesis-associated nuclear genes is much more impaired in the mutants in the dark and following red or far-red light short treatments or continuous light, than that of those phytochrome-dependent genes tested which are not associated with photosynthesis. Furthermore, red/far-red photoreversible responses involving photosynthesis-related genes (induction of Lhcb1–cab promoter activity, and photoreversible extent of greening) mediated by phytochrome B and other photo-stable phytochromes, both show a reduction in the cue mutants, which correlates with the etioplast defect. Our evidence demonstrates that plastid-derived signals need to be operational in order for the phytochrome control of photosynthetic nuclear genes to occur.
影响因子：
10.5
作者：
Moller, SG;Kunkel, T;Chua, NH
通讯作者：
Chua, NH