月季花瓣数量遗传分析

以‘窄叶藤本月季花’( Rosa chinensis ‘Zhaiye Tengben Yuejihua’)ב月月粉’( R. chinensis ‘Old Blush’)杂交群体为材料, 分析其花瓣数量的分离特点, 对单瓣花与重瓣花的花芽分化过程进行观察, 并对花瓣、雄蕊及瓣化雄蕊进行表皮细胞超微结构的观察.结果显示...     

Molecular analysis of hormone-regulated petal regeneration in Petunia

The petal is an important floral organ of higher plants. To study the mechanism of petal development, the in vitro regeneration system of petals was established in Petunia. High-frequency induction of petals occurred directly from explants on the media containing the combination of N6-benzyladenine (6-BA) and indole-3-acetic acid (IAA). Expression analysis of genes involved in flower development indicated that these genes were classified into three types. ABERRANT LEAF AND FLOWER (ALF) gene was induced during petal regeneration. Whereas, B-class and E-class genes, and genes involved in cell division were constitutively upregulated. In contrast, C-class and D-class genes were not expressed in explants and regenerated tissues. Further, in situ hybridization analysis showed that both ALF and GREEN PETAL (GP) expression were spatially regulated. The results suggest that differential regulation of gene expression occurs in the presence of hormones during petal regeneration, and hormone-regulated gene expression might be required for petal regeneration. This study provides the preliminary information to understand the mechanism of petal regeneration.     

The involvement of tonoplast proton pumps and Na+(K+)/H+ exchangers in the change of petal color during flower opening of Morning Glory, Ipomoea tricolor cv. Heavenly Blue

The petal color of morning glory, Ipomoea tricolor cv. Heavenly Blue, changes from purplish red to blue during flower opening. This color change is caused by an unusual increase in vacuolar pH from 6.6 to 7.7 in the colored adaxial and abaxial cells. To clarify the mechanism underlying the alkalization of epidermal vacuoles in the open petals, we focused on vacuolar H+-ATPase (V-ATPase), H+-pyrophosphatase (V-PPase) and an isoform of Na+/H+ exchanger (NHX1). We isolated red and blue protoplasts from the petals in bud and fully open flower, respectively, and purified vacuolar membranes. The membranes contained V-ATPase, V-PPase and NHX1, which were immunochemically detected, with relatively high transport activity. NHX1 could be detected only in the vacuolar membranes prepared from flower petals and its protein level was the highest in the colored petal epidermis of the open flower. These results suggest that the increase of vacuolar pH in the petals during flower opening is due to active transport of Na+ and/or K+ from the cytosol into vacuoles through a sodium- or potassium-driven Na+(K+)/H+ exchanger NXH1 and that V-PPase and V-ATPase may prevent the over-alkalization. This systematic ion transport maintains the weakly alkaline vacuolar pH, producing the sky-blue petals.     

PLANTLETS FROM PETAL SEGMENTS,PETAL EPIDERMIS,AND SHOOT TIPS OF THE PERICLINAL CHIMERA,CHRYSANTHEMUM MORIFOLIUM ‘INDIANAPOLIS'

Cultivated chrysanthemums, especially the greenhouse series of ‘Indianapolis’ cultivars, are probably periclinal chimeras for flower color. Therefore, in vitro propagation of chrysanthemum, which has recently been described, might produce plants not true to type. To test this, plantlets were generated from cultures of petal segments, petal epidermis, and shoot tips; these plantlets were grown to flowering to determine whether chrysanthemums with two genetically different chimeral layers in the petals are stable in tissue culture. Layer I displaced layer II in the formation of new meristematic areas in shoot tip and petal culture, showing that such chimeras are unstable in culture. Many more abnormal morphological types were exhibited by the plants which were regenerated from petal cultures rather than those from shoot tip cultures. Abnormalities included quilled and incised petal forms, as well as lack of anthocyanin pigmentation, characteristics which may not be attributable to the rearrangement of chimeral layers. Paramutation, true mutation, and environmenal effects are offered as possible explanations for this phenomenon.     

Petal Development in Lotus japonicus

Previous studies have demonstrated that petal shape and size in legume flowers are determined by two separate mechanisms, dorsoventral (DV) and organ internal (IN) asymmetric mechanisms, respectively. However, little is known about the molecular mechanisms controlling petal development in legumes. To address this question, we investigated petal development along the floral DV axis in Lotus japonicus with respect to cell and developmental biology by comparing wild‐type legumes to mutants. Based on morphological markers, the entire course of petal development, from initiation to maturity, was grouped to define 3 phases or 13 stages. In terms of epidermal micromorphology from adaxial surface, mature petals were divided into several distinct domains, and characteristic epidermal cells of each petal differentiated at stage 9, while epidermal cells of all domains were observed until stage 12. TCP and MIXTA‐like genes were found to be differentially expressed in various domains of petals at stages 9 and 12. Our results suggest that DV and IN mechanisms interplay at different stages of petal development, and their interaction at the cellular and molecular level guides the elaboration of domains within petals to achieve their ideal shape, and further suggest that TCP genes determine petal identity along the DV axis by regulating MIXTA‐like gene expression.     

大花铁线莲单重被花的转录组差异分析

以即可开单被花又可开重被花的大花铁线莲重被品种"薇安"为研究对象,对"薇安"同一时期同一植株上的3种不同花瓣类型（单被、半重被、重被）采用高通量测序技术进行拼接及功能注释,筛选不同花被类型下表达量高度差异的关键基因后进行实时荧光定量PCR验证。结果显示：转录组测序共产生13.8GB原始数据,3个转录本文库两两比较共获得3 075条差异表达基因（DEG）,其中单被花与半重被样本对比（A vs B）包括649条上调DEG,605条下调DEG;半重被花与重被花对比（B vs C）包括上调DEG 1 046条和下调DEG 721条;单被花与重被花对比（A vs C）有上调DEG 1 129条和下调DEG 859条。3个不同花被下共存的差异表达基因有134条。根据基因功能注释从总DEG中筛选出26条可能与重瓣化性状相关的基因进行聚类分析,并随机挑选10个目的基因进行荧光定量PCR验证。PCR结果显示这些基因的表达量在铁线莲"薇安"同一时期同一植株的3种花被类型中均存在显著差异。最终筛选出与铁线莲重瓣化相关的关键基因有MADS-BOX类基因PMADS1、AP3、FRUITFULL、FLC;生长素反应蛋白IAA9、生长素输入载体、脱落酸8'羟化酶、吲哚乙酸诱导蛋白ARG7等。本研究为探究铁线莲重瓣花分子机制提供了基础数据和理论依据。     

The Roles of Colour and Shape in Pollinator Deception in the Orchid Mantis Hymenopus coronatus

The orchid mantis Hymenopus coronatus (Insecta: Mantodea) is a deceptive predator that attracts pollinators as prey. Their resemblance to a flower has given rise to the hypothesis that they are flower mimics. However, floral mimicry as a predatory strategy, and in particular, how predatory floral mimicry functions at a mechanistic level is poorly understood. Two main morphological characteristics are thought to make orchid mantises appear similar to flowers and thus attractive to pollinators: (1) their ‘flower‐like’ white colouration and (2) their ‘petal‐shaped’ expansions of exoskeleton on their mid‐femur and hind femur (femoral lobes). I investigated the contribution of these colour and shape characteristics to pollinator attraction using artificial orchid mantis models. Models with the ‘flower‐like’ white colouration of the orchid mantis had higher rates of pollinator inspection than brown models. Manipulating overall body shape by removing or changing the orientation of the ‘petal‐shaped’ femoral lobes did not affect the attractiveness of models. As certain flower‐like characteristics (symmetry and petals) did not affect the attractiveness of models, pollinators may not necessarily cognitively misclassify orchid mantises as flowers. Rather, mantises may be exploiting sensory biases of their pollinator prey, and their UV‐absorbing white colouration may be sufficient to lure pollinators. The effectiveness of using artificial models established here provides a basis for future research into orchid mantis morphology and the fine‐scale interactions between orchid mantises and pollinators.     

梅花‘南京红须’、‘南京红’花色的呈现特征(英文)

梅花‘南京红须’、‘南京红’的花色主要存在着花发育阶段导致的时间变化,反映其花色受花发育控制。二者的花色都在蕾期最浓艳,在初花期略淡,在盛花期又稍浓,在末花期最淡,尽管花瓣在花开放时便开始衰老;在整个花发育时期,同一朵花不同层次花瓣的颜色浓淡均为:外层花瓣>中层花瓣>内层花瓣,即花瓣在花冠中的具体排列位置决定着该片花瓣的特定颜色深浅;但不同层次花瓣颜色的变化趋势不完全一致。同时,两个品种外层花瓣的总黄酮含量变化与外层花瓣的色度变化成正相关。而花朵在树冠的着生部位导致的花色差异极不显著,表明‘南京红须’、‘南京红’的花色的空间变化极微。本文可为梅花红色花色的机理探索和花色色素生物合成关键酶基因cDNA克隆中的花朵选择提供参考。     

中国六个城市大菊品种资源现状调查研究

对中国6个代表城市的大菊品种资源计2732份材料进行了调查、拍照及性状记录.通过比对分析,共整理出大菊品种1429个,现有品种可分为8个色系、5个瓣型和43个花型.其中黄色系居多,有500个品种,超过1/3,少见绿色、间色和双色品种.瓣型以平瓣为主,总计626个品种,占总数的44％,管瓣、匙瓣类次之,分别为414个和3...     

Gene trap lines define domains of gene regulation in Arabidopsis petals and stamens

To identify genes involved in Arabidopsis thaliana petal and stamen organogenesis, we used a gene trap approach to examine the patterns of reporter expression at each stage of flower development of 1765 gene trap lines. In 80 lines, the reporter gene showed petal- and/or stamen-specific expression or lack of expression, or expression in distinct patterns within the petals and/or the stamens, including distinct suborgan domains of expression, such as tissue-specific lines marking epidermis and vasculature, as well as lines demarcating the proximodistal or abaxial/adaxial axes of the organs. Interestingly, reporter gene expression was typically restricted along the proximodistal axis of petals and stamens, indicating the importance of this developmental axis in patterning of gene expression domains in these organs. We identified novel domains of gene expression along the axis marking the midregion of the petals and apical and basal parts of the anthers. Most of the genes tagged in these 80 lines were identified, and their possible functions in petal and/or stamen differentiation are discussed. We also scored the floral phenotypes of the 1765 gene trap lines and recovered two mutants affecting previously uncharacterized genes. In addition to revealing common domains of gene expression, the gene trap lines reported here provide both useful markers and valuable starting points for reverse genetic analyses of the differentiation pathways in petal and stamen development.     

荷花“重瓣化”的花器官形态发育比较观察

荷花（Nelumbo nucifera）的花型可分5种,最原始为单瓣型,然后由单瓣演化出半重瓣、重瓣、重台和千瓣型。为了揭示荷花重瓣化的分子机理,有必要从花器官的形态发育特征探究荷花花型成因及“重瓣化”的形态发育特征。实验分别选取5种荷花花型的代表品种：‘单洒锦’（单瓣型）、‘大洒锦’（重瓣型）、‘中山红台’（重台型）、‘至尊千瓣’（全重瓣型）、‘千瓣莲’（千瓣型）为材料,进行花芽分化过程形态的石蜡切片比较观察。结果发现：花芽分化过程中5个品种的萼片原基分化期和花瓣原基分化期相似,而雄蕊和雌蕊原基发育存在明显差异：单瓣、重瓣和重台品种均有正常的雄蕊和雌蕊原基分化;全重瓣品种发育初期有雄蕊及雌蕊原基分化,但后期全部瓣化;‘千瓣莲’品种不形成雄蕊和雌蕊原基,而是直接形成2至多个“花瓣增殖中心”,并由此不断分化出细小花瓣。研究认为重瓣型荷花品种的“重瓣化”花瓣主要来源于雄蕊的向心式瓣化,其次是雌蕊瓣化,属于雌雄蕊起源。而对于‘千瓣莲’型品种,花瓣的具体来源方式、花托是否直接参与瓣化及其在重瓣化过程中的作用有待于结合分子生物学手段开展进一步研究。     

Patterns of cell division and expansion in developing petals of Petunia hybrida

The definition of the patterns of cell division and expansion in plant development is of fundamental importance in understanding the mechanics of morphogenesis. By studying cell division and expansion patterns, we have assembled a developmental map of Petunia hybrida petals. Cycling cells were labelled with in situ markers of the cell cycle, whereas cell expansion was followed by assessing cell size in representative regions of developing petals. The outlined cell division and expansion patterns were related to organ asymmetry. Initially, cell divisions are uniformly distributed throughout the petal and decline gradually, starting from the basal part, to form a striking gradient of acropetal polarity. Cell areas, in contrast, increased first in the basal portion and then gradually towards the petal tip. This growth strategy highlighted a cell size control model based on cell-cycle departure time. The dorso-ventral asymmetry can be explained in terms of differential regulation of cell expansion. Cells of the abaxial epidermis enlarged earlier to a higher final extent than those of the adaxial epidermis. Epidermal appendage differentiation contributed to the remaining asymmetry. On the whole our study provides a sound basis for mutant analyses and to investigate the impact of specific (environmental) factors on petal growth.     

Organ boundary NAC‐domain transcription factors are implicated in the evolution of petal fusion

• Research rationale: Evolution of fused petals (sympetaly) is considered to be an important innovation that has repeatedly led to increased pollination efficiency, resulting in accelerated rates of plant diversification. Although little is known about the underlying regulation of sympetaly, genetic pathways ancestrally involved in organ boundary establishment (e.g. CUP SHAPED COTYLEDON [CUC] 1–3 genes) are strong candidates. In sympetalous petunia, mutations in the CUC1/2‐like orthologue NO APICAL MERISTEM (NAM) inhibit shoot apical meristem formation. Despite this, occasional ‘escape shoots’ develop flowers with extra petals and fused inter‐floral whorl organs.
• Central methods: To To determine if petunia CUC‐like genes regulate additional floral patterning, we used virus‐induced silencing (VIGS) following establishment of healthy shoot apices to re‐examine the role of NAM in petunia petal development, and uniquely characterise the CUC3 orthologue NH16.
• Key results: Confirming previous results, we found that reduced floral NAM/NH16 expression caused increased petal–stamen and stamen–carpel fusion, and often produced extra petals. However, further to previous results, all VIGS plants infected with NAM or NH16 constructs exhibited reduced fusion in the petal whorl compared to control plants.
• Main conclusions: Together with previous data, our results demonstrate conservation of petunia CUC‐like genes in establishing inter‐floral whorl organ boundaries, as well as functional evolution to affect the fusion of petunia petals.