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向光性是植物为捕捉更多光能而建立起来的对不良光照条件的适应机制之一．蓝光被证明是引起植物向光性最有效的光源．最近的研究进一步揭示植物体内一定存在一种对蓝光具特殊敏感性从而引起向光性反应的光受体．光生物学家已克隆得到数种ｃＤＮＡ并证明它们当中至少有一种对向光性受体负责，遗憾的是至今并没有弄清楚到底是哪一种ｃＤＮＡ表达向光性受体．就诱导向光性反应而言，红光是无效的，但早在本世纪５０年代就已有人证明红光对植物向光性行为产生深刻影响．最新的研究（Ｌｉｕ＆Ｉｉｎｏ１９９６）已证明红光对蓝光所诱导向光性的影响是由光敏色素这一红光／远红光受体参与调节的．研究发现对蓝光和远红光敏感的向光性受由对红光敏感的光敏色素的严格控制．绝对黑暗条件下生长的植物向光性蓝光刺激无反应，不表现向光性．这样的植物只有接受了红光或远红光前处理后才对向光性蓝光刺激有反应．这一重大发现揭示了向光性反应中光敏色素与向光性受体的相互作用，并为光生物学家彻底搞清楚植物向光性受体提供了一条全新的研究思路．本文就是在这一背景基础上总结了近几年来有关光敏色素和向光性方面研究的新进展．我们希望通过这样的工作能使有关植物向光性受体和植物体内吸收不同波长光的光受体?
Phototropism is one of the mechanisms that plants adapt to poor lighting conditions to capture more light energy. Blu-ray has been shown to be the most efficient light source that causes plants to phototropism. Recent studies further revealed that there must be a photoreceptor in the plant that possesses a particular sensitivity to blue light to cause photoreaction. Photobiologists have cloned several cD-NA and proved that at least one of them is responsible for photoreceptors. Unfortunately, so far it has not been clear which cDNAs are expressed toward photoreceptors. Red light is ineffective in inducing photoreactions, but as early as the 1950s it has been demonstrated that red light has a profound effect on plant phototropism. Recent studies (Liu & Iino 1996) have demonstrated that the red-light-induced photoluminescence effect is mediated by the phytochrome, a red / far red receptor. It has been found that the phototropism sensitive to blue light and far red light is tightly controlled by the red light sensitive photochromic dye. Plants grown under absolutely dark conditions have no response to photopheresis and do not exhibit phototropism. Such a plant responds only to photoluminescent stimulus only after it has been subjected to pre-treatment with red or far red light. This major discovery reveals the interaction of phytochromes with photoreceptors in photoreactions and provides a completely new understanding of what photoreceptors can do to photobiologists. This article is based on this background and summarizes the recent progress in the research on phytochromes and phototropics. We hope that through such work can make the plants to photoreceptors and plants absorb different wavelengths of light photoreceptors?