不同光质对毛地黄叶愈伤组织培养的影响

本文通过五种不同光质诱导毛地黄叶愈伤组织的生长和继代培养,20天后测定不同光质诱导的愈伤组织中次生代谢产物的含量,进一步探讨植物组织培养中光质的调控作用。     

不同波长的光对佛甲草离体茎段培养过程中生长发育的影响

植物的正常个体发育过程中都存在着一个受光控制的光形态建成过程。光作为植物组织培养中的一个调控因子,已有报道。本实验通过对佛甲草的不同波长的光处理,比较其形态发生及生理生化指标。佛甲草为一种药用植物,本实验为建立佛甲草茎段培养的理想诱导模式提供了初步的资料。     

植物光反应突变体

光信号转导途径是植物发育调控机制的中心组成部分。目前在植物光信号受体及下游转导组分突变体筛选方面已经取得许多重要结果。本文综述了这些突变体和光信号转导途径组成及调控机制研究方面的进展。     

植物光反应突变体

光信号转导途径是植物发育调控机制的中心组成部分。目前在植物光信号受体及下游转导组分突变体筛选方面已经取得许多重要结果。本文综述了这些突变体和光信号转导途径组成及调控机制研究方面的进展。     

光受体介导信号转导调控植物开花研究进展

光照是影响植物生长发育的重要环境因子, 开花是高等植物生活史上最重要的事件。植物通过光受体感知外界环境中的光照变化, 激活一系列信号转导过程从而适时开花。该文介绍了高等植物光受体的种类、结构特征和生理功能的研究进展, 并系统阐述了红光/远红光受体光敏色素、蓝光受体隐花色素以及FKF1/ZTL/LKP2等介导光信号调控植物开花的分子机制, 包括光受体对CO转录及转录后水平调控和对FT转录水平的调控等。此外, 还介绍了光受体整合光信号与温度和赤霉素等信号调控植物开花的研究进展, 并展望了未来的研究方向。     

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。     

光质对花叶芋离体培养的生理生态效应

自从de Capite首次将光因子应用于植物组织培养的调控以来,对高等植物组织培养中光质效应的研究正越来越受到人们的关注,已有一些报道,但大多侧重于形态学方面的,而作为一种生态因子光质在植物组织培养系统中生理生态效应的研究较少。光质不仅对双色花叶芋(Caladium bicolor)组织培养中的器官发生有影响,而且对其生理生化过程也产生影响,因此,本实验以光质对双色花叶芋离体培养的生理生态效应为中心,着重探讨了光质对叶绿素a、叶绿素b及类胡萝卜素含量、过氧化物酶、过氧化氢酶活力、碳水化合物、蛋白质、DNA及RNA含量的影响。有关光质对整体栽培植物体内色素含量影响的情况已有大量报道,但很少有人进行过离体条件下的实验。另外,过氧化物酶及过氧     

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。     

植物HY5蛋白结构与功能的研究进展

HY5（LONG HYPOCOTYL 5）为光形态建成的正调控因子,是光调控植物发育的分子开关。在光诱导的基因表达中,HY5调控着植物基因组中上千基因的表达,它既可以单独调控相关基因的表达,也可以与其他调控因子一起共同调控相关基因的表达。HY5蛋白除了在光形态建成中起作用外,还在植物激素的信号传递过程中起着极其重要的作用,它整合了光信号传递和植物激素的信号传递。本综述简要介绍HY5蛋白的结构、生理功能及其分子机制等方面有关的进展。     

植物组织培养新技术:光自养微繁

系统地综述了常规植物组织培养存在的不足,如易染菌、生长周期长、生产成本高等,从而引出了光自养微繁的概念、研究现状、控制方向以及它的优势。如植株长势较好、生长周期短、生产成本低等,并对该技术做了展望。光自养微繁技术作为一种新型的组织培养方法,克服了传统组培无法克服的缺陷,必将成为今后组培生产的一种重要手段。     

Entrainment of Arabidopsis roots to the light:dark cycle by light piping

Correct operation of the plant circadian clock is crucial for optimal growth and development. Recent evidence has shown that the plant clock is tissue specific and potentially hierarchical, implying that there are signalling mechanisms that can synchronise the clock in different tissues. Here, I have addressed the mechanism that allows the shoot and root clocks to be synchronised in light:dark cycles but not in continuous light. Luciferase imaging data from 2 different Arabidopsis accessions with 2 different markers show that the period of the root clock is much less sensitive to blue light than to red light. Decapitated roots were imaged either in darkness or with the top section of root tissue exposed to light. Exposure to red light reduced the period of the root tissue maintained in darkness, whereas exposure to blue light did not. The data indicate that light can be piped through root tissue to affect the circadian period of tissue in darkness. I propose that the synchronisation of shoots and roots in light:dark cycles is achieved by light piping from shoots to roots.     

Measurement of light gradients and spectral regime in plant tissue with a fiber optic probe

A method is described in which light gradients and spectral regime can be measured within plant tissue using fiber optics. A fiber optic probe was made by modifying a single optical fiber (200 μm diameter) so that it had a light harvesting end that was a truncated tip 20–70 μm in diameter. The probe was a directional sensor with a half-band acceptance angle of 17–20°. Light measurements were made as the fiber optic probe was driven through plant tissue by a motorized micromanipulator, and the light that entered the fiber tip was piped to a spectroradiometer. By irradiating green leaf tissue of the succulent Crassula falcata L. with collimated light and inserting the probe from different directions, it was possible to measure light quality and quantity at different depths. Collimated light was scattered completely by the initial 1.0 mm of leaf tissue, which also greatly attenuated all light except the green and far-red. Light scatter contributed significantly to light quantity and had a pronounced spectral structure. Immediately beneath the irradiated surface the amount of light at 550 nm was 1.2 times that of the incident light. The light gradient declined rapidly to 0.5 times incident light at 1.4 mm depth. In contrast, the amount of light at 750 nm increased during the initial 0.5 mm to 2.9 times incident light and then declined linearly to 0.5 times incident light at the dark side of the leaf (4.5 mm). The implications of the magnitude of the contribution of light scatter to the light gradient is also discussed.     

Effects of light regimes on anther culture response in bread wheat

This experiment was initiated to further test the effects of light regimes during callus induction and plant regeneration on anther culture response of spring wheat (Triticum aestivum L.). Spring wheat cultivars 'Edwall' and 'WA 7176' with high callus induction from anther culture but low green plant production were used. Different gro-lux light and dark regimes during callus induction, and gro-lux light and fluorescent light regimes during plant regeneration were used. Callus induction decreased significantly at relatively high light intensity (315 μmol m⁻² s⁻¹) applied at any period of culture when compared to continuous dark. Light regimes used continuously and from the 15^th to the last day of callus induction also had a significant negative effect on plant regeneration compared to continuous dark and light application in the first half of callus induction. During plant regeneration, '15 day dark + 7 day gro-lux light' significantly increased plant regeneration compared to both 'gro-lux' and 'fluorescent light' regimes. Light regimes during both callus induction and plant regeneration and their interaction effects were found to be highly significant on green plant proportion and green plant yield. 'Continuous light' application during callus induction increased green plant proportion more than other applications in contrast to its negative effect on plant regeneration. During plant regeneration, '15 day dark + 7 day gro-lux light' had the higher green plant proportion compared to only 'fluorescent light' and only 'gro-lux light'. The highest green plant yields were obtained from '15 day dark + 7 day gro-lux light' during plant regeneration in combination with either 'continuous dark' or 'continuous light' regimes during callus induction. This revised version was published online in June 2006 with corrections to the Cover Date.     

Preventing photochemistry in culture media by long-pass light filters alters growth of cultured tissues

Exposure of plant tissue culture media to light from fluorescent bulbs changed the growth regulating properties of the media. The light caused nutrient medium-dependent photosensitized degradation of the phytohormone indole-3-acetic acid and other media components. Photochemical changes in culture media were caused by light from 290 to 450 nanometers and were prevented with a yellow long-pass filter. The use of appropriately filtered light when culturing plant material can eliminate unnecessary variability by stabilizing the culture media composition.     

Effect of Combined Changes in Culture Medium and Incubation Conditions on the Regeneration from Immature Embryos of Elite Varieties of Winter Wheat

In this study, tissue culture method for plant regeneration from immature embryos of elite Hungarian winter wheat varieties was established. The influence of the growth regulators and the concentration of macroelements in the regeneration medium and of the incubation temperature and light intensity on regeneration frequency were investigated. The most noticeable effect on regeneration frequency was achieved by simultaneously reducing both the incubation temperature to 23 °C and the concentration of macroelements in the regeneration medium to half-strength. This modification increased the average regeneration frequency from about 10–78%. Changes in the light intensity and temperature gave an average plant regeneration frequency of 83%.     

用于细胞及组织培养的高强度LED生物光源

本文研制出可用于细胞及组织培养的高强度发光二极管光源,介绍了此光源的光路原理和简要结构,测试了该光源的辐射照度及其强度分布,使用统计分析软件SPSS拟合得到该光源的辐射照度经验公式。     

Chloroplast avoidance movement is not functional in plants grown under strong sunlight

Chloroplast movement in nine climbing plant species was investigated. It is thought that chloroplasts generally escape from strong light to avoid photodamage but accumulate towards weak light to perform photosynthesis effectively. Unexpectedly, however, the leaves of climbing plants grown under strong sunlight showed very low or no chloroplast photorelocation responses to either weak or strong blue light when detected by red light transmittance through leaves. Direct observations of Cayratia japonica leaves, for example, revealed that the average number of chloroplasts in upper periclinal walls of palisade tissue cells was only 1.2 after weak blue‐light irradiation and almost all of the chloroplasts remained at the anticlinal wall, the state of chloroplast avoidance response. The leaves grown under strong light have thin and columnar palisade tissue cells comparing with the leaves grown under low light. Depending on our analyses and our schematic model, the thinner cells in a unit leaf area have a wider total plasma membrane area, such that more chloroplasts can exist on the plasma membrane in the thinner cells than in the thicker cells in a unit leaf‐area basis. The same strategy might be used in other plant leaves grown under direct sunlight.     

不同光强光质对艾草生长及挥发油成分积累的影响

为探究光照对艾(Artemisia argyi)的产量及主要挥发油成分积累的影响,以蕲艾组培苗为试材,采用高光强、红光、蓝光等进行不同光强光质处理实验。结果表明,高光强及蓝光处理可促进艾生物量积累,红光和蓝光处理可促进植株伸长。高光强、红光及蓝光均可提高艾叶挥发油中1,8-桉油素、β-萜品醇含量。高光强还能促进龙脑积累,而蓝光处理下可检测到较多在其他光照条件下未检测到的化合物,如萜烯和蓝桉醇等物质。对不同光强光质处理下光受体及光响应转录因子基因表达量进行分析,在高光强处理下,所有光受体的表达量均显著升高;而响应不同光质的对应光受体基因表达量增加。光受体基因表达与艾生物量及主要挥发油的相关性分析表明,光受体基因表达对艾草生物量的影响起重要作用,且不同光处理调控可通过光受体响应并级联调控相关基因表达,调控艾叶生长及挥发油的合成。高光强和蓝光处理下,艾草的生物量及有效挥发油代谢物增加,可在艾草栽培中加以应用。     

Influence of cultural and physiochemical factors on ascorbate stability in plant tissue culture media

Ascorbic acid rapidly decays in plant tissue culture media. Within 50 min to 3 h after preparing 100 mM solutions, ascorbic acid was destroyed. Autoclaving, shaking flasks, high light intensity and increasing pH over a range from 4.5–7 accelerated decay. Ascorbic acid was oxidized to dehydroascorbic acid which also underwent decay. Within 11 h and 15 min after adding ascorbic acid both ascorbic acid and its oxidation product, dehydroascorbic acid, disappeared from medium. Since ascorbic acid is rapidly destroyed in plant tissue culture media it may not exert its effect as an intact molecule. Instead its antioxidant/antibrowning role in plant cell, tissue and organ cultures may be mediated by some product of further oxidation.     

光照和温度对扇蕨孢子萌发的影响

用组织培养法和光学显微镜技术初步研究光照和温度影响扇蕨孢子萌发的结果表明,扇蕨孢子发芽是需光型,具有明显的光休眠现象。光照是孢子萌发的主要影响因子,25℃下,孢子萌发率达（85．1±5．1）％。相同温度下孢子即使在黑暗中培养50d也不能萌发,转入光照下后萌发率可达（82．4±6．6）％。孢子在光下的最适发芽温度为21．6-26．5℃,7d开始萌发,6-7周完全萌发,温度升高或下降均降低孢子萌发率。