植物的成花逆转

成花逆转是生长发发育过程中的特殊现象,与环境因素、成花决定的程度及遗传因素有关。逆转为我们从另一角度研究开花现象提供了一个枘地。文章主要介绍成花志的类型,研究成花的逆转的体系。引起成花逆转的因素以及逆转九一与成花决定之间的关系。     

植物成花转变基因的研究现状

介绍了拟南芥中与开花相关的一系列控制成花的基因,包括花分生组织特异性基因和COPS基因,这些基因相互作用,通过成花抑制路径、自发促进路径、光周期促进路径和春化促进路径来调节植物的成花转变。     

植物的成花决定

在成花诱导结束后,植物就具备了分化花的能力,即进入了成花决定态。文中着重介绍植物获得这一能力的过程及其特征,即植物成花决定过程及成花决定态的问题。     

植物成花调控的分子遗传学

对以拟南芥为主要对象进行的有关成花调控分子遗传学研究作了综述。该领域的研究已明确了对成花的调控没有单一的“成花万能基因”,而是有一群“成花时期基因”,并大致弄清了这些基因调控成花的模式。其结果是,成花调控途径具有多重性和冗长性,这些成花调控基因的参与量、基因之间的平衡都对成花起着重要的作用。     

植物成花转变及成花逆转的研究进展

本文主要讨论了植物成花转变及成花逆转等开花研究中应用分子生物学技术所取得的一些进展,描述了成花决定态的特性,5个从拟南芥中分离获得的成花转变的基因,有关光受体的分子生物学研究和造成成花逆转的原因等。     

龙眼的成花逆转与“冲梢”调控

龙眼的成花逆转以部分开花和／或花序逆转两种类型出现,其逆转是以“冲梢”形成而发生的,“冲梢”导致龙眼“大小年”结果。文章就60年代以来龙其是近10来年龙眼花芽分化和成花逆转,与成花逆转有关的因素,以及成花转调控等方面的研究进展作介绍。     

温度对植物成花的影响

温度对于植物成花的影响是多方面的,本文主要从低温、高温和昼夜温差三方面综述了温度影响成花之生理学方面的研究结果。认为温度处理的效果发生于成花启动之前和/或成花启动进程中的较早步骤,其作用可能是间接的。     

温度对植物成花的影响

温度对于植物成花的影响是多方面的 ,本文主要从低温、高温和昼夜温差三方面综述了温度影响成花之生理学方面的研究结果。认为温度处理的效果发生于成花启动之前和 /或成花启动进程中的较早步骤 ,其作用可能是间接的。     

光温外界信号、植株状态与成花决定

植物由营养生长状态转向生殖生长状态（成花转变）是发育过程中的重要一步。经过一段时期营养生长的植株,便自动进入成花感受态,在这种状态下植株才能够对外界信号产生应答反应而启动成花过程。本文主要讨论光周期和温度对成花的作用     

光温外界信号、植株状态与成花决定

植物由营养生长状态转向生殖生长状态(成花转变)是发育过程中的重要一步。经过一段时期营养生长的植株,便自动进入成花感受态,在这种状态下植株才能够对外界信号产生应答反应而启动成花过程。本文主要讨论光周期和温度对成花的作用。     

In vitro formation and development of floral buds on tobacco stem explants: effects of kinetin and other factors

Stem segments were excised from plants of Wisconsin 38 tobacco (Nicotiana tabacum L.) in three regions differing in their distance below the inflorescence. They were cultured in vitro in 8- or 16-hr days. After 8 weeks, floral and vegetative buds were counted, and extent of floral development was assessed. Kinetin at 10(-5)m inhibited formation and development of floral buds regardless of indoleacetic acid concentration. Supplied at this concentration with adequate auxin, kinetin stimulated vegetative bud formation and may have caused floral bud abortion. Indoleacetic acid (>/= 10(-6)m) inhibited vegetative and floral bud formation when supplied with low kinetin concentration (/= 10(-6)m), it inhibited floral bud formation and stimulated vegetative bud formation. More floral buds were formed in 16-hr days than in 8-hr days. Few formed on explants other than those derived from the region nearest the inflorescence regardless of other treatment.     

低营养条件下Paclobutrazol(PP333)对黄瓜去顶幼苗直接形成花芽的影响(简报)

植物开花机理是生物学中的一个基本问题,多年来人们进行过许多的研究,积累了大量的事实,然而对开花的机理仍然还不甚清楚。因而在利用原有实验系统的同时,有必要寻找更多简单,又便于分析的实验系统。Jullien等报告离体培养的大豆子叶节能直接产生花芽。我们在建立离体培养黄瓜子叶直接单独形成雄花或雌花的实验系统的过程中,发现黄瓜幼苗去除顶芽后在子叶节处也能直接形成花芽。这一现象有可能用于深入研究各营养器官和花启动间关系等问题,定将     

水稻花发育的分子生物学研究进展

水稻是世界上最重要的粮食作为之一,也是单子叶植物发育生物学研究较理想的模式植物。水稻花器官还是粮食赖以形成的基础。对水稻花发育的研究已开始成为植物分子遗传学的一个新的焦点。近年来有关水稻花发育基因调控的研究已取得了长足的进展,本文从水稻花的诱导、花分生组织的形成和花器官的发育三个方面综述近年来国内外的研究进展。 Abstract:Rice (Oryza sativa L.) is not only one of the most important food crops in the world,but also a model plant for study of molecular developmental biology in monocots.In addition,the rice floral organs provide the basis for grain formation.Study of rice floral development has become a new focus of plant molecular genetics.Recently,notable progress has been made in study of gene regulation in rice floral development.In the review,genetic and molecular mechanisms of floral induction,floral meristem formation,and floral organ development in rice are summarized.     

黄瓜离体子叶节花芽和营养芽分化中CFL基因的表达

CFL基因是从黄瓜中克隆到的拟南芥LEAFY(LFY)同源基因.以离体黄瓜子叶培养物成花为实验体系,利用mRNA原位杂交技术对CFL基因在花芽和营养芽分化过程中的时空表达进行了分析.结果如下:在花芽分化过程中,CFL基因在花原基形成、花器官原基分化及各轮花器官形成之初强表达,在花器官形成以后表达减弱或不表达;在营养芽分化过程中,CFL基因在分生组织、叶原基和幼叶中有明显表达,在成熟组织中不表达.结果说明CFL基因的表达在黄瓜子叶节花芽和营养芽分化中原基的分化形成是必需的.结果提示CFL基因可能参与细胞分裂调控和启动、营养性分生组织向花分生组织转变等过程.     

The Arabidopsis FILAMENTOUS FLOWER gene is required for flower formation.

A screen for mutations affecting flower formation was carried out and several filamentous flower (fil) alleles were identified. In fil mutants, floral primordia occasionally give rise to pedicels lacking flowers at their ends. This defect is dramatically enhanced in fil rev double mutants, in which every floral primordium produces a flowerless pedicel. These data suggest that the FIL and REV genes are required for an early step of flower formation, possibly for the establishment of a flower-forming domain within the floral primordium. The FIL gene is also required for establishment of floral meristem identity and for flower development. During flower development, the FIL gene is required for floral organ formation in terms of the correct numbers and positions; correct spatial activity of the AGAMOUS, APETALA3, PISTILLATA and SUPERMAN genes; and floral organ development.     

Arranging the bouquet of disease: floral traits and the transmission of plant and animal pathogens

Several floral microbes are known to be pathogenic to plants or floral visitors such as pollinators. Despite the ecological and economic importance of pathogens deposited in flowers, we often lack a basic understanding of how floral traits influence disease transmission. Here, we provide the first systematic review regarding how floral traits attract vectors (for plant pathogens) or hosts (for animal pathogens), mediate disease establishment and evolve under complex interactions with plant mutualists that can be vectors for microbial antagonists. Attraction of floral visitors is influenced by numerous phenological, morphological and chemical traits, and several plant pathogens manipulate floral traits to attract vectors. There is rapidly growing interest in how floral secondary compounds and antimicrobial enzymes influence disease establishment in plant hosts. Similarly, new research suggests that consumption of floral secondary compounds can reduce pathogen loads in animal pollinators. Given recent concerns about pollinator declines caused in part by pathogens, the role of floral traits in mediating pathogen transmission is a key area for further research. We conclude by discussing important implications of floral transmission of pathogens for agriculture, conservation and human health, suggesting promising avenues for future research in both basic and applied biology.     

Responsiveness to abscisic acid of embryos of dormant oat (Avena sativa) seeds. Involvement of ABA-inducible proteins

An in vitro bioassay system for floral bud formation has been established using Nicotiana tabacum L. cv. MC, explants excised from floral stalks cultured on modified Murashige-Skoog medium containing excess auxin and antiauxin. Three auxins. indolyl-3-acetic acid (IAA), 4-chloroindolyl-3-acetic acid and 5,6-dichloroindolyl-3-acetic acid, were tested for floral bud-forming activity; IAA was most efficient. Three antiauxins. 5,7-dichlorindolyl-3-isobutyric acid (5,7-Cl₂-HBA), p -chlorophenoxyiso butyric acid and 2,3,5-triiodobenzoic acid, were tested for the ability to reverse the inhibition of floral bud formation caused by excess IAA. Only 5,7-Cl₂-HBA was very effective. Leaf exudates from short day- and long day-treated tobacco plants were added to the bioassay system which contained 1 µ M 6-benzylaminopurine, 5 µ M IAA and 5 µ M 5, 7-Cl₂-HBA, Interestingly, only the leaf exudate from short day-treated plants stimulated floral bud formation. Moreover, the buds produced grew into large. well-developed ones with shapes similar to those of the natural floral buds of intact tobacco plants.     

低温和水分亏缺对常绿果树成花作用研究进展(综述)

本文综述了低温和水分亏缺对常绿果树成花作用的最新研究结果,包括不同果树成花对胁迫过程中树体发生的生理变化,以及可能的作用机理等,提出了低温和水分亏缺对成花作用的模式图,展望了研究方向.     

春兰×大花蕙兰杂种试管苗开花现象

以野生春兰(Cymbidiumgoeringii)为母本,大花蕙兰(C.hybridium)为父本进行杂交,由杂交种子获得800多个春兰×大花蕙兰杂种原球茎无性系。其中一个杂种株系的原球茎继代培养2个月后,形成肉眼可见的花蕾。诱导花芽形成的最适激素组合为6-BA1.0mg/L+NAA0.1mg/L,总花芽形成率达31%。诱导花芽形成的最适材料为1￣2cm幼苗,花芽形成率达19%。