Verification at the protein level of the PIF4-mediated external coincidence model for the temperature-adaptive photoperiodic control of plant growth in Arabidopsis thaliana.
Verification at the protein level of the PIF4-mediated external coincidence model for the temperature-adaptive photoperiodic control of plant growth in Arabidopsis thaliana.
复制标题
DOI：
10.4161/psb.23390
复制
发表时间：
2013-03
影响因子：
2.9
通讯作者：
Mizuno T
中科院分区：
文献类型：
--
作者：
Yamashino T;Nomoto Y;Lorrain S;Miyachi M;Ito S;Nakamichi N;Fankhauser C;Mizuno T
植物昼夜节律时钟控制着广泛的生理和发育事件，包括短日照(SDS)特有的促进去黄化过程中下胚轴的伸长以及营养生长过程中叶柄的伸长。在拟南芥中，编码光敏色素相互作用的碱性螺旋-环-螺旋(BHLH)转录因子的PIF4基因在光周期控制植物生长中起着关键作用。根据所提出的外部符合模型，PIF4基因在夜间特异地在SDS中早熟转录，在这种条件下蛋白质产物稳定积累，而PIF4仅在白天长日(LDS)表达，在这种条件下，蛋白质产物被光激活的PhyB降解，残留的蛋白质被Della蛋白家族失活。以前的一些报告提供了确凿的证据支持这一符合模型，主要是在PIF4和PIF4靶基因的转录水平上。然而，PIF4蛋白的昼夜振荡曲线还没有被证明，它被认为是依赖于光周期和环境温度的。在这里，我们提出了在PIF4蛋白水平上的关键证据，以进一步支持外部符合模型，该模型潜在的温度适应性光周期控制植物生长。
Plant circadian clock controls a wide variety of physiological and developmental events, which include the short-days (SDs)-specific promotion of the elongation of hypocotyls during de-etiolation and also the elongation of petioles during vegetative growth. In A. thaliana, the PIF4 gene encoding a phytochrome-interacting basic helix-loop-helix (bHLH) transcription factor plays crucial roles in this photoperiodic control of plant growth. According to the proposed external coincidence model, the PIF4 gene is transcribed precociously at the end of night specifically in SDs, under which conditions the protein product is stably accumulated, while PIF4 is expressed exclusively during the daytime in long days (LDs), under which conditions the protein product is degraded by the light-activated phyB and also the residual proteins are inactivated by the DELLA family of proteins. A number of previous reports provided solid evidence to support this coincidence model mainly at the transcriptional level of the PIF4 and PIF4-traget genes. Nevertheless, the diurnal oscillation profiles of PIF4 proteins, which were postulated to be dependent on photoperiod and ambient temperature, have not yet been demonstrated. Here we present such crucial evidence on PIF4 protein level to further support the external coincidence model underlying the temperature-adaptive photoperiodic control of plant growth in A. thaliana.