共查询到20条相似文献,搜索用时 78 毫秒
1.
Molecular aspects of flower development in grasses 总被引:1,自引:0,他引:1
2.
Inflorescences and flowers in the grass species have characteristic structures that are distinct from those in eudicots. Owing to the availability of genetic tools and their genome sequences, rice and maize have become model plants for the grasses and for the monocots in general. Recent studies have provided much insight into the genetic control of inflorescence and flower development in grasses, especially in rice and maize. Progress in elucidating the developmental mechanisms in each of these plants may contribute greatly to our understanding of the evolution of development in higher plants. 相似文献
3.
Flowering and determinacy in maize 总被引:2,自引:0,他引:2
All plant organs are produced by meristems, groups of stem cells located in the tips of roots and shoots. Indeterminate meristems make an indefinite number of organs, whereas determinate meristems are consumed after making a specific number of organs. Maize is an ideal system to study the genetic control of meristem fate because of the contribution from determinate and indeterminate meristems to the overall inflorescence. Here, the latest work on meristem maintenance and organ specification in maize is reviewed. Genetic networks, such as the CLAVATA components of meristem maintenance and the ABC programme of flower development, are conserved between grasses and eudicots. Maize and rice appear to have conserved mechanisms of meristem maintenance and organ identity. Other pathways, such as sex determination, are likely to be found only in maize with its separate male and female flowers. A rich genetic history has resulted in a large collection of maize mutants. The advent of genomic tools and synteny across the grasses now permits the isolation of the genes behind inflorescence architecture and the ability to compare function across the Angiosperms. 相似文献
4.
Ikeda-Kawakatsu K Maekawa M Izawa T Itoh J Nagato Y 《The Plant journal : for cell and molecular biology》2012,69(1):168-180
The temporal and spatial control of meristem identity is a key element in plant development. To better understand the molecular mechanisms that regulate inflorescence and flower architecture, we characterized the rice aberrant panicle organization 2 (apo2) mutant which exhibits small panicles with reduced number of primary branches due to the precocious formation of spikelet meristems. The apo2 mutants also display a shortened plastochron in the vegetative phase, late flowering, aberrant floral organ identities and loss of floral meristem determinacy. Map-based cloning revealed that APO2 is identical to previously reported RFL gene, the rice ortholog of the Arabidopsis LEAFY (LFY) gene. Further analysis indicated that APO2/RFL and APO1, the rice ortholog of Arabidopsis UNUSUAL FLORAL ORGANS, act cooperatively to control inflorescence and flower development. The present study revealed functional differences between APO2/RFL and LFY. In particular, APO2/RFL and LFY act oppositely on inflorescence development. Therefore, the genetic mechanisms for controlling inflorescence architecture have evolutionarily diverged between rice (monocots) and Arabidopsis (eudicots). 相似文献
5.
6.
Usha Vijayraghavan 《Journal of biosciences》1996,21(3):379-395
Flower development provides a model system to study mechanisms that govern pattern formation in plants. Most flowers consist
of four organ types that are present in a specific order from the periphery to the centre of the flower. Reviewed here are
studies on flower development in two model species:Arabidopsis thaliana andAntirrhinum majus that focus on the molecular genetic analysis of homeotic mutations affecting pattern formation in the flower. Based on these
studies a model was proposed that explains how three classes of regulatory genes can together control the development of the
correct pattern of organs in the flower. The universality of the basic tenets of the model is apparent from the analysis of
the homologues of theArabidopsis genes from other plant species 相似文献
7.
8.
9.
Di Stilio VS Kramer EM Baum DA 《The Plant journal : for cell and molecular biology》2005,41(5):755-766
In most dioecious angiosperm species, flowers are initially perfect but abort either stamens or carpels during their development, indicating that sex determination occurs after floral organ identity has been established. Dioecious members of the genus Thalictrum (meadow-rue), however, produce flowers that lack aborted organs. Examination of early flower development of T. dioicum confirms that flowers are male or female from inception, raising the possibility that genetic mechanisms working at or above the level of organ identity promote sex determination through a homeotic-like mechanism. In order to investigate this possibility, we identified homologs of the organ identity genes PISTILLATA (PI), APETALA3 (AP3) and AGAMOUS (AG) from T. dioicum and the hermaphroditic species T. thalictroides. A combination of early and late duplication events was uncovered in these gene lineages and expression analyses indicate that these events are generally associated with divergence in gene regulation. In light of these findings, we discuss the potential of T. dioicum as a new model for the study of sex determination in the basal eudicots. 相似文献
10.
Turning floral organs into leaves, leaves into floral organs. 总被引:14,自引:0,他引:14
11.
12.
Evolutionary conservation of angiosperm flower development at the molecular and genetic levels 总被引:7,自引:0,他引:7
John L. Bowman 《Journal of biosciences》1997,22(4):515-527
Flowers consist primarily of four basic organ types whose relative positions are universally conserved within the angiosperms.
A model has been proposed to explain how a small number of regulatory genes, acting alone and in combination, specify floral
organ identity. This model, known widely as the ABC model of flower development, is based on molecular generic experiments
in two model organisms,Arabidopsis thaliana
and
Antirrhinum majus.Both of these species are considered to be eudicots, a clade within the angiosperms with a relatively conserved floral architecture.
In this review, the application of the ABC model derived from studies of these typical eudicot species is considered with
respect to angiosperms whose floral structure deviates from that of the eudicots. It is concluded that the model is universally
applicable to the angiosperms as a whole, and the enormous diversity seen among angiosperms flowers is due to genetic pathways
that are downstream, or independent, of the genetic programme that specifies floral organ identity. 相似文献
13.
Conversion of leaves into petals in Arabidopsis 总被引:22,自引:0,他引:22
More than 200 years ago, Goethe proposed that each of the distinct flower organs represents a modified leaf [1]. Support for this hypothesis has come from genetic studies, which have identified genes required for flower organ identity. These genes have been incorporated into the widely accepted ABC model of flower organ identity, a model that appears generally applicable to distantly related eudicots as well as monocot plants. Strikingly, triple mutants lacking the ABC activities produce leaves in place of flower organs, and this finding demonstrates that these genes are required for floral organ identity [2]. However, the ABC genes are not sufficient for floral organ identity since ectopic expression of these genes failed to convert vegetative leaves into flower organs. This finding suggests that one or more additional factors are required [3, 4]. We have recently shown that SEPALLATA (SEP) represents a new class of floral organ identity genes since the loss of SEP activity results in all flower organs developing as sepals [5]. Here we show that the combined action of the SEP genes, together with the A and B genes, is sufficient to convert leaves into petals. 相似文献
14.
Whipple CJ Ciceri P Padilla CM Ambrose BA Bandong SL Schmidt RJ 《Development (Cambridge, England)》2004,131(24):6083-6091
The ABC model of flower development, established through studies in eudicot model species, proposes that petal and stamen identity are under the control of B-class genes. Analysis of B- and C-class genes in the grass species rice and maize suggests that the C- and B-class functions are conserved between monocots and eudicots, with B-class genes controlling stamen and lodicule development. We have undertaken a further analysis of the maize B-class genes Silky1, the putative AP3 ortholog, and Zmm16, a putative PI ortholog, in order to compare their function with the Arabidopsis B-class genes. Our results show that maize B-class proteins interact in vitro to bind DNA as an obligate heterodimer, as do Arabidopsis B-class proteins. The maize proteins also interact with the appropriate Arabidopsis B-class partner proteins to bind DNA. Furthermore, we show that maize B-class genes are capable of rescuing the corresponding Arabidopsis B-class mutant phenotypes. This demonstrates B-class activity of the maize gene Zmm16, and provides compelling evidence that B-class gene function is conserved between monocots and eudicots. 相似文献
15.
Lee JY Baum SF Oh SH Jiang CZ Chen JC Bowman JL 《Development (Cambridge, England)》2005,132(22):5021-5032
Nectaries are secretory organs that are widely present in flowering plants that function to attract floral pollinators. Owing to diversity in nectary positions and structures, they are thought to have originated multiple times during angiosperm evolution, with their potential contribution to the diversification of flowering plants and pollinating animals being considerable. We investigated the genetic basis of diverse nectary forms in eudicot angiosperm species using CRABS CLAW (CRC), a gene required for nectaries in Arabidopsis. CRC expression is conserved in morphologically different nectaries from several core eudicot species and is required for nectary development in both rosids and asterids, two major phylogenetic lineages of eudicots. However, in a basal eudicot species, no evidence of CRC expression in nectaries was found. Considering the phylogenetic distribution of nectary positions and CRC expression analyses in eudicots, we propose that diverse nectaries in core eudicots share conserved CRC gene regulation, and that derived nectary positions in eudicots have altered regulation of CRC. As the ancestral function of CRC lies in the regulation of carpel development, it may have been co-opted as a regulator of nectary development within the eudicots, concomitant with the association of nectaries with reproductive organs in derived lineages. 相似文献
16.
Lilan Hong a Qian Qian b Keming Zhu c Ding Tang a Zejun Huang a Ling Gao a Ming Li a Minghong Gu c Zhukuan Cheng a a State Key Laboratory of Plant Genomics National Center for Plant Gene Research 《Acta Genetica Sinica》2010,(2)
17.
水稻花发育的分子生物学研究进展 总被引:8,自引:0,他引:8
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. 相似文献
18.
19.
Flower and fruit development in Arabidopsis thaliana 总被引:2,自引:0,他引:2
20.
Conservation and diversity in flower land 总被引:1,自引:0,他引:1
During the past decade, enormous progress has been made in understanding the molecular regulation of flower development. In particular, homeotic genes that determine the identity of the floral organs have been characterised from different flowering plants, revealing considerable conservation among angiosperm species. On the other hand, evolutionary diversification has led to enormous variation in flower morphology. Increasing numbers of reports have described differences in the regulation, redundancy and function of homeotic genes from various species. These fundamentals of floral organ specification are therefore an ideal subject for comparative analyses of flower development, which will lead to a better understanding of plant evolution, plant development and the complexity of molecular mechanisms that control flower development and morphology. 相似文献