高等植物春化作用研究进展

环境因子(低温诱导或称春化作用)在高等植物的生长发育调控中起着重要作用。本文就近年来春化作用诱导的开花启动研究领域中的进展从春化过程中的多步骤性、成花决定过程控制的多途径性、接受春化刺激的位置与分化启动的关系、以及春化作用的分子机理等几个方面进行了简要综述。并对春化相关基因克隆方面的进展进行了分析和综述。     

植物春化特性及春化作用机理

春化作用是某些高等植物成花转变的重要环节,被认为是植物在低温诱导下促使其相关基因的表达,从而导致生理状态转变的一种受遗传控制的生理过程。本文对植物春化反应特性、春化作用的生理生化特性及春化作用的分子生物学等方面的研究进展进行了概述,并对春化研究中的问题进行了分析和展望。     

植物春化特性及春化作用机理

春化作用是某些高等植物成花转变的重要环节,被认为是植物在低温诱导下促使其相关基因的表达,从而导致生理状态转变的一种受遗传控制的生理过程.本文对植物春化反应特性、春化作用的生理生化特性及春化作用的分子生物学等方面的研究进展进行了概述,并对春化研究中的问题进行了分析和展望.     

植物春化用的分子机理

春化作用在控制高等植物开花中起着重要的作用。本文综述了近年来以拟南芥(Arabidopsis thaliana)和冬小麦(Triticum aestivum)为主要研究对象进行的有关春化作用分子机制的研究; 概括和分析了已经分离得到的与春化有关的基因的功能及其调控方式以及各基因间的相互作用。     

植物春化作用的分子机理

春化作用在控制高等植物开花中起着重要的作用。本文综述了近年来以拟南芥（Arabidopsis thaliana）和冬小麦（Triticum aestivum）为主要研究对象进行的有关春化作用分子机制的研究;概括和分析了已经分离得到的与春化有关的基因的功能及其调控方式以及各基因间的相互作用。     

冬小麦春化相关基因cDNA(verc203)片段序列的分析

春化作用是高等植物发育的重要环节之一,它是受遗传控制的生理过程,人们对此现象已作了生态、生理和生化方面的研究（谭克辉1983）。认为植物茎尖生长点接受低温诱导后,会引起体内许多代谢途径和方式的顺序改变（种康和谭克辉1993）,可能导致春化相关基因启动表达。有人（Burn等1993）提出春化相关基因启动表达可能是基因脱甲基化结果的观点。但这一假说尚缺乏直接的强有力证据。违斌和谭克辉（199）系统地研究了冬小麦春化过程中核酸、蛋白质代谢与春化作用的直接相关关系和春化特异蛋白质代谢与特异性rnRNA出现的重要意义,确信春化…     

植物春化作用的分子机制及应用

植物能响应环境中的低温信号实现开花调控，这种经历低温促使植物开花的作用即为春化作用。本文结合国内外春化作用的研究进展，概述春化作用的发现和特点，阐述模式植物拟南芥及单子叶作物的春化作用分子机制，并举例说明春化作用在农业、园艺等方面的应用。     

冬小麦春化过程中低温诱导的与花芽分化相关的mRNA和蛋白质的合成

应用SDS电泳及高分辨双向电泳技术,分析了冬小麦经春化、脱春化及超期春化处理后茎类蛋白质组分的变化。发现52.5,38kD和16.2kD蛋白质与冬小麦开花诱导密切相关。mRNA体外翻译结果表明,春化作用中低温诱导与开花紧密相关的mRNA的出现有一定的顺序性。因此推测:春化诱导开花是低温导致某些特定基因表达的结果,而表达的调节主要发生在转录水平上。     

春化处理控制冬小麦的小穗发育

春化作用是决定冬性及二年草本植物成花和穗化的一个关键生理过程,通过用不同时间的前期低温处理,观察对冬小麦（Triticum aestivum L.)后期形态建成中穗分化启动,小花发育及结实率的影响,发现前期低温处理对穗启动分化的早晚具有决定作用,春化时间越长,穗分化启动越早,较长时间低温有利于促进穗分化,在实验室低温处理条件下,促进小花分化和提高结实率的最佳春化处理时间是45d左右,实验观察表明,春化处理促进小麦生长锥分化启动时间和分化速率,减少小穗退化,这一结果表明了春化处理不仅是冬小麦开花启动过程所必需的,而且是花序正常发育过程和顶部与基部小穗完全结实所不可缺少的。     

小麦春化发育的分子调控机理研究进展

春化发育特性是小麦品种的重要性状,直接影响着小麦品种的种植范围和利用效率.本文就小麦春化相关基因的发现,以及对春化相关基因VRN1、VRN2和VRN3的克隆、表达特性以及春化发育分子调控机理方面的研究进展进行了综述.     

FLC基因表达在植物春化过程中的作用

在对以往有关不同开花途径研究简要总结的基础上综述了FLC基因在春化过程中的作用。近期以拟南芥不同生态型和突变体为模式的研究结果表明基因FLC可能是春化反应的关键基因。研究发现 ,FLC的表达水平与植株低温处理的时间呈数量关系 ,低温处理时间越长 ,FLC的表达越弱 ,去甲基化也可能对FLC起负调控的作用。同时FLC也存在于自主开花途径中 ,与其他基因共同作用以调节植株开花时间。而FLC的表达对开花起抑制作用。一系列研究表明 ,春化的低温作用可能在于相关基因的去甲基化 ,消除了FLC对开花的抑制作用 ,从而解除赤霉素合成途径的封锁最终导致植株在一定时期开花。     

冬小麦低温春化过程中茎尖细胞超微结构的变化与玉米赤霉烯酮的关系

玉米赤霉烯酮(zearalenone, ZEN)是Stob等于1962年首先从玉米赤霉菌培养物中分离出的次生代谢产物,它具有动物雌性激素的作用,也能促进某些真菌形成子实体,被认为是真菌的一种性激素,80年代初发现亦存在于高等植物体内。多年的研究结果表明,ZEN与植物的许多发育过程,包括春化作用、光周期诱导以及授粉受精过程均有密切的关系,可能ZEN参与了小麦成花诱导过程的调控,但其调控机制不明。为进一步研究小麦春化过程中茎尖细胞超微结构的变化与ZEN的相关性,我们以春化过程中的冬小麦幼芽为材料,对茎尖细胞超微结构以及与之相应的ZEN含量变化进行了分析。     

Heading date QTL in a spring × winter barley cross evaluated in Mediterranean environments

Heading date is a key trait for the adaptation of barley to Mediterranean environments. We studied the genetic control of flowering time under Northern Spanish (Mediterranean) conditions using a new population derived from the spring/winter cross Beka/Mogador. A set of 120 doubled haploid lines was evaluated in the field, and under controlled temperature and photoperiod conditions. Genotyping was carried out with 215 markers (RFLP, STS, RAPD, AFLP, SSR), including markers for vernalization candidate genes, HvBM5 (Vrn-H1), HvZCCT (Vrn-H2), and HvT SNP22 (Ppd-H1). Four major QTL, and the interactions between them, accounted for most of the variation in both field (71–92%) and greenhouse trials (55–86%). These were coincident with the location of the major genes for response to vernalization and short photoperiod (Ppd-H2 on chromosome 1H). A major QTL, near the centromere of chromosome 2H was the most important under autumn sowing conditions. Although it is detected under all conditions, its action seems not independent from environmental cues. An epistatic interaction involving the two vernalization genes was detected when the plants were grown without vernalization and under long photoperiod. The simultaneous presence of the winter Mogador allele at the two loci produced a marked delay in heading date, beyond a mere additive effect. This interaction, combined with the effect of the gene responsive to short photoperiod, Ppd-H2, was found responsible of the phenomenon known as short-day vernalization, present in some of the lines of the population. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Thermoinduction of genes encoding the enzymes of gibberellin biosynthesis and a putative negative regulator of gibberellin signal transduction in<Emphasis Type="Italic"> Eustoma grandiflorum</Emphasis>

Eustoma grandiflorum Shinn requires vernalization for the induction of stem elongation and flowering. To investigate the role of gibberellins (GAs) in vernalization, the expression levels of genes encoding enzymes of GA biosynthesis, copalyl diphosphate synthetase, GA 20-oxidase and GA 3-hydroxylase, were examined using two culitvars that show different responses to vernalization. The three genes were induced in a vernalization- and a cultivar-dependent manner. EgSPY, a putative negative regulator of GA signal transduction, was also induced during the vernalization period. The results suggest that the expression of the genes encoding GAs biosynthesis is regulated by vernalization. We postulate that EgSPY functions as a negative regulator of GA signal transduction during vernalization, inhibiting adventitious shoot elongation during vernalization.Communicated by K.K. Kamo     

Identification of genes expressed in the shoot apex ofBrassica campestris during floral transition

The vegetative-to-floral transition ofBrassica campestris cv. Osome was induced by vernalization. Poly(A)+RNA was isolated from the transition shoot apex after 6 weeks of vernalization, the floral apex after 12 weeks of vernalization and the expanded leaves just before vernalization, and cDNAs were synthesized. These cDNAs were used for subtraction and differential screening to select cDNA preferentially present in the transition and floral apices. Nucleotide sequences of the resulting 14 cDNA clones were determined, and northern blot analysis was carried out on six cDNAs. Two cDNA clones which did not show significant similarity to known genes were shown to be preferentially expressed in the floral apex.     

小麦品种耐寒性与春化VRN-1等位基因的关系研究

以来自11个省份的134个小麦品种为试验材料,于2009-2010年在石家庄种植,调查冻害情况;并利用分子标记鉴定VRN-1等位基因组成,以明确小麦品种春化VRN-1等位基因组成与耐寒性的关系。结果表明:小麦品种的耐寒性与其VRN-1等位基因组成、地理来源和耐旱性等因素有密切关系。当地理来源相同时,品种的耐寒性一般随着VRN-1等位基因控制的春化效应的增强而减弱;当VRN-1等位基因组成相同时,品种的耐寒性一般随着地理来源的纬度降低而减弱。本研究结果为小麦品种的耐寒性改良提供了重要参考。     

Mapping loci controlling vernalization requirement and flowering time in Brassica napus

Rapeseed cultivars (Brassica napus L.) can be classified into annual and biennial groups according to their requirement for vernalization in order to induce flowering. The genetic control of these phenotypic differences is not well understood, but this information could be valuable for the design of breeding approaches to accelerate rapeseed improvement. In order to map loci controlling this variation, a doubled haploid population, derived from a cross between annual and biennial cultivars, was evaluated for vernalization requirement and days-to-flowering in a replicated field experiment using three treatments: no vernalization, 4 weeks of vernalization and 8 weeks of vernalization. A linkage map of 132 RFLP loci was used to locate loci controlling these traits. Marker segregation in one region of linkage group 9 was strongly associated with the annual/biennial growth habit in the unvernalized treatment and with days-to-flowering in all three treatments. Two other regions with smaller effects on days-to-flowering were also identified.