藻类的光控发育

藻类发育的许多方面受光的调控,且多种多样的光受体参与藻类的光形态建成过程。本文就近年来藻类光形态建成领域的研究进展简要综述,内容以海洋藻类为主,主要包括光周期、非光周期控制的藻类发育类型,以及藻类的光受体的种类及分子特性,并兼顾与高等植物的相关特性进行比较。     

光敏色素分子及其信号转导途径

作为植物体内的一种光受体,光敏色素在植物的光形态建成过程中意义重大。植物光敏色素及由它介导的信号传导途径是目前细胞生物学、发育生物学和分子生物学研究的热点之一。本文介绍了光敏色素的分子特性、生理功能和信号转导途径等方面的研究进展。     

我国光形态建成研究回顾

对国内和海外中国科学家在植物光形态建成领域的研究进行了简要的总结和回顾。本文内容包括光敏色素调节的反应及其信号转导,蓝光反应及其信号转导,光周期调节及光形态建成的其他几个方面。     

我国光形态建成研究回顾

对国内和海外中国科学家在植物光形态建成领域的研究进行了简要的总结和回顾。本文内容包括光敏色素调节的反应及其信号转导,蓝光反应及其信号转导,光周期调节及光形态建成的其他几个方面。     

植物的光敏色素

光敏色素作为植物体内的一种光受体,在植物的光形态建成过程中意义重大,本文对光敏色素的分子特性,生理功能,作用方式及基因表达调控等方面的研究作系统的总结。     

高等植物光信号应答的分子基础

光不仅为高等植物进行光合作用提供能源,同时还作为一种重要的发育信号而调控植物形态建成,影响其几乎全部的生命周期。就高等植物对光信号感受和应答的分子基础进行了综述,根据已有研究结果对高等植物可能的光信号传导通路作了一个粗略的概括,并简要介绍本试验室在水稻农垦58S光周期育性转换研究中所取得的初步结果。     

高等植物开花时程的调控与光受体Ⅰ.开花时程的基因与光受体调控

系统评述了高等植物开花时程的调控与植物光受体的联系.重点说明了控制开花时程的遗传途径以及光周期途径的有关基因的研究进展.影响高等植物开花的最重要的因子之一便是光周期,光周期对高等植物开花的调控是通过相关基因间的相互作用来实现的,这些基因包括参与花启动发育控制基因,昼夜节律时间钟调控基因及光受体信号转导基因.近5年左右的时间通过对拟南芥及其一系列突变体的研究为我们展示了这一热门领域的广阔的前景.     

植物的光受体及其调控机制的研究

近年来,通过对植物的分子遗传学研究,在植物光受体及其在光形态建成中对植物生长发育的调控机制方面取得了显著进展。从光受体及基因家族的概况,包括光敏色素、隐花色素、向光素的基本结构、分子特征、基因和信号转导等,介绍了光受体在光控发育调节机制方面的研究进展情况。     

大麦发育模型及其光敏感参数

为了确定光周期对作物影响的连续变化规律,采用大麦自交系为材料,通过大麦自交系从长日照到短日照和从短日照到长日照环境有规律地进行相互转移的试验方法,定量地研究了光周期对大麦自交系诱导的响应。结果表明:光周期对大麦生长发育的影响呈阶段性线性关系。据此将大麦花前期发育阶段划分为基本营养生长期(BVP)、光敏感期(PSP)和光敏感后期(PPP)。建立了光周期影响大麦发育的数学模型,计算出花前期各发育阶段的天数,然后根据大麦光温发育模拟模型确定模型参数:它们分别是f0(最短花前期)、θ1和θ2(光敏感期起始时间和光敏感期终止时间)、δ(光敏感系数);估出96个大麦品系(包括两个亲本)的发育模型参数。计算结果表明,96个大麦品系均受光周期的影响,不同的大麦品系感光性差异较大,最早的在出苗后9.78d就进入光敏感期,最迟的在播种后41.49d进入光敏感期;最快的9.2d通过光敏感期,最慢的光敏感期一直持续到抽穗前;不同的发育阶段光周期对大麦的影响也有明显的区别,表现为光敏感期强烈地受光周期的影响,而在基本营养生长期和光敏感后期的影响较小;并分析了大麦抽穗前各发育阶段的长短与感光性强弱的关系。     

光控发育和光敏色素的研究进展

植物发育是其遗传基因在环境因子作用下,在一定的时间和空间组合下的顺序和协调的表达。光是环境因子中对发育调控作用最广泛、最明显的一个因子。绝大部分光调节反应是不可逆的形态建成反应。所谓光形态建成(photomor-phogenesis)就是光控发育的意思。它是由多个光受体参与调节的复杂过程,这些光受体是光敏色素(phytochrome)、隐花色素(cryptochrome)、紫外光-β受体。近一个世纪来光控发育研究从整体到细胞、最近到大分子水平不断地发展,近20年来积累了大量的资料,形成了一个分支学科。在植物的光生物学中,它是和光合作     

Plant pigments: the many faces of light perception

Good reviews have been published over the years regarding many aspects of plant response to light, such as important advances in understanding the molecular mechanisms of light perception, signaling and control of gene expression by the photoreceptors. Moreover, many efforts have been undertaken on the manipulation of these mechanisms to improve horticultural crop production. In this paper we present an overview about the photoreceptors, the relationship between their absorptive and reflective properties and their control of plant development as well perspectives focused on photomorphogenesis manipulation.     

Light signals in leaf and chloroplast development: photoreceptors and downstream responses in search of a transduction pathway

Light affects both the development and the metabolism of plants. In addition to the role of light in providing energy for photosynthesis, light signals cause profound changes in the morphology of the developing young seedling, including cotyledon expansion, leaf development, inhibition of stem growth, and production of chlorophyll in the photosynthetically competent chloroplast. The light-dependent development of plants (photomorphogenesis) is a complex process resulting from the combined action of several photoreceptors. This review summarizes what is known of the red- and blue-light photoreceptors that regulate dicotyledonous seedling development and the complexity of the downstream responses. Special emphasis is placed on the recent progress made toward genetic and biochemical dissection of the signal transduction pathways.     

A COP1‐PIF‐HEC regulatory module fine‐tunes photomorphogenesis in Arabidopsis

Light responses mediated by the photoreceptors play crucial roles in regulating different aspects of plant growth and development. An E3 ubiquitin ligase complex CONSTITUTIVELY PHOTOMORPHOGENIC1 (COP1)1/SUPPRESSOR OF PHYA (SPA), one of the central repressors of photomorphogenesis, is critical for maintaining skotomorphogenesis. It targets several positive regulators of photomorphogenesis for degradation in darkness. Recently, we revealed that basic helix‐loop‐helix factors, HECATEs (HECs), function as positive regulators of photomorphogenesis by directly interacting and antagonizing the activity of another group of repressors called PHYTOCHROME‐INTERACTING FACTORs (PIFs). It was also shown that HECs are partially degraded in the dark through the ubiquitin/26S proteasome pathway. However, the underlying mechanism of HEC degradation in the dark is still unclear. Here, we show that HECs also interact with both COP1 and SPA proteins in darkness, and that HEC2 is directly targeted by COP1 for degradation via the ubiquitin/26S proteasome pathway. Moreover, COP1‐mediated polyubiquitylation and degradation of HEC2 are enhanced by PIF1. Therefore, the ubiquitylation and subsequent degradation of HECs are significantly reduced in both cop1 and pif mutants. Consistent with this, the hec mutants partially suppress photomorphogenic phenotypes of both cop1 and pifQ mutants. Collectively, our work reveals that the COP1/SPA‐mediated ubiquitylation and degradation of HECs contributes to the coordination of skoto/photomorphogenic development in plants.