Cryptic red-light signal produced by a rapid Pfr-action of phytochrome.

光敏色素家族由几个分子物种组成。光敏色素信号通路被不同类别的光感受器的这些相互作用或作用所放大或抑制。在此之前，我们曾报道过PFR介导的花色苷合成是由一种不同的光敏色素分子产生的隐蔽红光信号(CRS)放大的。在本研究项目中，我们研究了PFR信号通路，重点研究了CRS.1的产生和作用。结果表明，CRS是由光敏色素作用产生的，其一半逃逸时间约为1 S。在本实验中，我们搭建了一台发光二极管辐照装置，对10毫秒量级的红光(R)和远红光(FR)脉冲进行重复照射。研究cAMP和cGMP在CRS作用中的作用。鸟苷酸环化酶活性的升高似乎与CRS的作用有关。目前正在分析环核苷酸与CRS的关系。在利用番茄光敏色素突变体进行CRS研究的过程中，我们首先鉴定了光感受器PhyA，它在长时间的FR.4下抑制种子的萌发。除CRS外，PFR作用的放大因子是由UV-B光感受器产生的。PFR诱导的高粱花色苷合成的放大作用谱显示，排除CRS的影响。

The phytochrome family comprises several molecular species. The phytochrome-signaling pathways are amplified or suppressed by these interactions or actions of different classes of photoreceptors. Previously we reported that Pfr-mediated anthocyanin synthesis in Sorghum bicolor is amplified by a cryptic red-light signal (CRS) produced by the action of a distinct molecular species of phytochrome. In this research project, we investigated Pfr-signaling pathways focusing on the production and the action of CRS.1. We showed that CRS is produced by very rapid phytochrome action whose half escape time is approximately 1 s. For this experiment an LED irradiation apparatus was constructed which programmed repeated irradiation of red light (R) and far-red light (FR) pulses of 10-ms order.2. The involvement of cAMP and cGMP in the CRS action was studied. The increased activity of guanyl cyclase seems to correlate to CRS action. The relationship between cyclic nucleotides and CRS is being analyzed now.3. In the course of the CRS-study using phytochrome mutants of tomato, we first identified the photoreceptor as phyA that inhibits seed germination under prolonged FR.4. An amplification factor of Pfr-action other than CRS is generated by a UV-B photoreceptor. It was shown by the action spectrum for amplification of Pfr-induced anthocyanin synthesis in sorghum determined excluding the CRS effect.