FT overexpression induces precocious flowering and normal reproductive development in Eucalyptus.

PubMed

Klocko, Amy L; Ma, Cathleen; Robertson, Sarah; Esfandiari, Elahe; Nilsson, Ove; Strauss, Steven H

2016-02-01

Eucalyptus trees are among the most important species for industrial forestry worldwide. However, as with most forest trees, flowering does not begin for one to several years after planting which can limit the rate of conventional and molecular breeding. To speed flowering, we transformed a Eucalyptus grandis × urophylla hybrid (SP7) with a variety of constructs that enable overexpression of FLOWERING LOCUS T (FT). We found that FT expression led to very early flowering, with events showing floral buds within 1-5 months of transplanting to the glasshouse. The most rapid flowering was observed when the cauliflower mosaic virus 35S promoter was used to drive the Arabidopsis thaliana FT gene (AtFT). Early flowering was also observed with AtFT overexpression from a 409S ubiquitin promoter and under heat induction conditions with Populus trichocarpa FT1 (PtFT1) under control of a heat-shock promoter. Early flowering trees grew robustly, but exhibited a highly branched phenotype compared to the strong apical dominance of nonflowering transgenic and control trees. AtFT-induced flowers were morphologically normal and produced viable pollen grains and viable self- and cross-pollinated seeds. Many self-seedlings inherited AtFT and flowered early. FT overexpression-induced flowering in Eucalyptus may be a valuable means for accelerating breeding and genetic studies as the transgene can be easily segregated away in progeny, restoring normal growth and form. © 2015 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

EARLY FLOWERING3 Redundancy Fine-Tunes Photoperiod Sensitivity1[OPEN

PubMed Central

Rubenach, Andrew J.S.; Vander Schoor, Jacqueline K.; Aubert, Gregoire; Burstin, Judith

2017-01-01

Three pea (Pisum sativum) loci controlling photoperiod sensitivity, HIGH RESPONSE (HR), DIE NEUTRALIS (DNE), and STERILE NODES (SN), have recently been shown to correspond to orthologs of Arabidopsis (Arabidopsis thaliana) circadian clock genes EARLY FLOWERING3 (ELF3), ELF4, and LUX ARRHYTHMO, respectively. A fourth pea locus, PHOTOPERIOD (PPD), also contributes to the photoperiod response in a similar manner to SN and DNE, and recessive ppd mutants on a spring-flowering hr mutant background show early, photoperiod-insensitive flowering. However, the molecular identity of PPD has so far remained elusive. Here, we show that the PPD locus also has a role in maintenance of diurnal and circadian gene expression rhythms and identify PPD as an ELF3 co-ortholog, termed ELF3b. Genetic interactions between pea ELF3 genes suggest that loss of PPD function does not affect flowering time in the presence of functional HR, whereas PPD can compensate only partially for the lack of HR. These results provide an illustration of how gene duplication and divergence can generate potential for the emergence of more subtle variations in phenotype that may be adaptively significant. PMID:28202598

Early floral development of Heliconia latispatha (Heliconiaceae), a key taxon for understanding the evolution of flower development in the Zingiberales.

PubMed

Kirchoff, Bruce K; Lagomarsino, Laura P; Newman, Winnell H; Bartlett, Madelaine E; Specht, Chelsea D

2009-03-01

We present new comparative data on early floral development of Heliconia latispatha, an ecologically and horticulturally important tropical plant within the order Zingiberales. Modification of the six members of two androecial whorls is characteristic of Zingiberales, with a reduction in number of fertile stamen from five or six in the banana families (Musaceae, Strelitziaceae, Lowiaceae, and Heliconiaceae) to one in Costaceae and Zingiberaceae and one-half in Marantaceae and Cannaceae. The remaining five infertile stamens in these later four families (the ginger families) are petaloid, and in Costaceae and Zingiberaceae fuse together to form a novel structure, the labellum. Within this developmental sequence, Heliconiaceae share with the ginger families the possession of an antisepalous staminode, a synapomorphy that has been used to place Heliconiaceae as sister to the ginger family clade. Here, we use epi-illumination light microscopy and reconstruction of serial sections to investigate the ontogeny of the Heliconia flower with emphasis on the ontogeny of the staminode. We compare floral development in Heliconia with that previously described for other species of Zingiberales. A comparison of floral structure and development across Zingiberales is presented to better understand the evolution of the flower in this charismatic group of tropical plants.

Mineral and metabolic profiles in tea leaves and flowers during flower development.

PubMed

Jia, Sisi; Wang, Yu; Hu, Jianhui; Ding, Zhaotang; Liang, Qing; Zhang, Yinfei; Wang, Hui

2016-09-01

Tea [Camellia sinensis (L.) O. Kuntze] is one of the most popular non-alcoholic beverage crops in the world, and the physiological processes and gene regulations involved in development in tea plants have been well characterized. However, relatively little is known about the metabolic changes combined with mineral distributions that occur during flower development. Here we detected the contents of 11 elements in tea leaves and flowers and found that, some of them, especially phosphorus, sulfur and copper, showed significant changes during tea flowering. We also detected 122 metabolites in tea leaves and flowers and found that, 72 of them showed significant differences between flowers and leaves, of which sugars, organic acids, and flavonoids dominated. The sugars, such as trehalose and galactose, all accumulated in tea flowers, and the organic acids, such as malic acid, citric acid and fumaric acid involved in TCA cycle. The flavonoids, like epicatechin, catechin gallate and epigallocatechin, were more abundant in leaves. Furthermore, we found that the contents of 33 metabolites changed during the development of flowers. Especially, citric acid, phenylalanine and most flavonoids decreased while fructose and galactose increased during flowering stages in flowers. We also analyzed the correlations between the ions and metabolites and found that, some mineral nutrients including phosphorus, sulfur, manganese and zinc had close relations to organic acids, flavonoids, sugars and several amino acids during flowering. We mapped the metabolic pathway according to the KEGG database. This work will serve as the foundation for a systems biology approach to the understanding of mineral metabolism. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Involvement of ethylene in sex expression and female flower development in watermelon (Citrullus lanatus).

PubMed

Manzano, Susana; Martínez, Cecilia; García, Juan Manuel; Megías, Zoraida; Jamilena, Manuel

2014-12-01

Although it is known that ethylene has a masculinizing effect on watermelon, the specific role of this hormone in sex expression and flower development has not been analyzed in depth. By using different approaches the present work demonstrates that ethylene regulates differentially two sex-related developmental processes: sexual expression, i.e. the earliness and the number of female flowers per plant, and the development of individual floral buds. Ethylene production in the shoot apex as well as in male, female and bisexual flowers demonstrated that the female flower requires much more ethylene than the male one to develop, and that bisexual flowers result from a decrease in ethylene production in the female floral bud. The occurrence of bisexual flowers was found to be associated with elevated temperatures in the greenhouse, concomitantly with a reduction of ethylene production in the shoot apex. External treatments with ethephon and AVG, and the use of Cucurbita rootstocks with different ethylene production and sensitivity, confirmed that, as occurs in other cucurbit species, ethylene is required to arrest the development of stamens in the female flower. Nevertheless, in watermelon ethylene inhibits the transition from male to female flowering and reduces the number of pistillate flowers per plant, which runs contrary to findings in other cucurbit species. The use of Cucurbita rootstocks with elevated ethylene production delayed the production of female flowers but reduced the number of bisexual flowers, which is associated with a reduced fruit set and altered fruit shape.

Overexpression of the cucumber LEAFY homolog CFL and hormone treatments alter flower development in gloxinia (Sinningia speciosa).

PubMed

Zhang, Ming-Zhe; Ye, Dan; Wang, Li-Lin; Pang, Ji-Liang; Zhang, Yu-Hong; Zheng, Ke; Bian, Hong-Wu; Han, Ning; Pan, Jian-Wei; Wang, Jun-Hui; Zhu, Mu-Yuan

2008-07-01

Leafy (LFY) and LFY-like genes control the initiation of floral meristems and regulate MADS-box genes in higher plants. The Cucumber-FLO-LFY (CFL) gene, a LFY homolog in Cucumis sativus L. is expressed in the primordia, floral primordia, and each whirl of floral organs during the early stage of flower development. In this study, functions of CFL in flower development were investigated by overexpressing the CFL gene in gloxinia (Sinningia speciosa). Our results show that constitutive CFL overexpression significantly promote early flowering without gibberellin (GA(3)) supplement, suggesting that CFL can serve functionally as a LFY homolog in gloxinia. Moreover, GA(3) and abscisic acid (ABA) treatments could modulate the expression of MADS-box genes in opposite directions. GA(3) resembles the overexpression of CFL in the expression of MADS-box genes and the regeneration of floral buds, but ABA inhibits the expression of MADS-box genes and flower development. These results suggest that CFL and downstream MADS-box genes involved in flower development are regulated by GA(3) and ABA.

Early flowering and seed production in a yellow birch progeny test

Treesearch

Knud E. Clausen

1976-01-01

Trees in a yellow birch progeny test began to bear seed when 7 years old and the proportion of fruiting trees increased in the following 2 years. Male catkins were produced at age 8 and the number of trees with males increased greatly the following years. Although there is much variation between and within families in earliness of flowering and in number of flowers and...

Flower Development and Sex Determination between Male and Female Flowers in Vernicia fordii

PubMed Central

Mao, Yingji; Liu, Wenbo; Chen, Xue; Xu, Yang; Lu, Weili; Hou, Jinyan; Ni, Jun; Wang, Yuting; Wu, Lifang

2017-01-01

Vernicia fordii is a monoecious and diclinous species with male and female flowers on the same inflorescence. Low female to male flower ratio is one of the main reasons for low yield in this species. However, little is known of its floral development and sex determination. Here, according to the results of scanning electron microscopy and histological analysis, the floral development of V. fordii was divided into 12 stages and the first morphological divergence between the male and female flowers was found to occur at stage 7. The male flowers are always unisexual, but the female flowers present bisexual characteristics, with sterile stamen (staminode) restricted to pre-meiosis of mother sporogenous cells and cell death occurring at later development stages. To further elucidate the molecular mechanism underling sex determination at the divergence stage for male and female flowers, comparative transcriptome analysis was performed. In total, 56,065 unigenes were generated and 608 genes were differentially expressed between male and female flowers, among which 310 and 298 DEGs (differentially expressed genes) showed high expression levels in males and females, respectively. The transcriptome data showed that the sexual dimorphism of female flowers was affected by jasmonic acid, transcription factors, and some genes related to the floral meristem activity. Ten candidate genes showed consistent expression in the qRT-PCR validation and DEGs data. In this study, we provide developmental characterization and transcriptomic information for better understanding of the development of unisexual flowers and the regulatory networks underlying the mechanism of sex determination in V. fordii, which would be helpful in the molecular breeding of V. fordii to improve the yield output. PMID:28775735

Flower Development and Sex Determination between Male and Female Flowers in Vernicia fordii.

PubMed

Mao, Yingji; Liu, Wenbo; Chen, Xue; Xu, Yang; Lu, Weili; Hou, Jinyan; Ni, Jun; Wang, Yuting; Wu, Lifang

2017-01-01

Vernicia fordii is a monoecious and diclinous species with male and female flowers on the same inflorescence. Low female to male flower ratio is one of the main reasons for low yield in this species. However, little is known of its floral development and sex determination. Here, according to the results of scanning electron microscopy and histological analysis, the floral development of V. fordii was divided into 12 stages and the first morphological divergence between the male and female flowers was found to occur at stage 7. The male flowers are always unisexual, but the female flowers present bisexual characteristics, with sterile stamen (staminode) restricted to pre-meiosis of mother sporogenous cells and cell death occurring at later development stages. To further elucidate the molecular mechanism underling sex determination at the divergence stage for male and female flowers, comparative transcriptome analysis was performed. In total, 56,065 unigenes were generated and 608 genes were differentially expressed between male and female flowers, among which 310 and 298 DEGs (differentially expressed genes) showed high expression levels in males and females, respectively. The transcriptome data showed that the sexual dimorphism of female flowers was affected by jasmonic acid, transcription factors, and some genes related to the floral meristem activity. Ten candidate genes showed consistent expression in the qRT-PCR validation and DEGs data. In this study, we provide developmental characterization and transcriptomic information for better understanding of the development of unisexual flowers and the regulatory networks underlying the mechanism of sex determination in V. fordii , which would be helpful in the molecular breeding of V. fordii to improve the yield output.

Early histological, hormonal, and molecular changes during pineapple (Ananas comosus (L.) Merrill) artificial flowering induction.

PubMed

Espinosa, Maita Eulalia Ávila; Moreira, Rafael Oliveira; Lima, André Almeida; Ságio, Solange Aparecida; Barreto, Horllys Gomes; Luiz, Sara Lazara Pérez; Abreu, Carlos Eduardo Aragón; Yanes-Paz, Ermis; Ruíz, Yanelis Capdesuñer; González-Olmedo, Justo Lorenzo; Chalfun-Júnior, Antonio

2017-02-01

Natural flowering can cause serious scheduling problems in the pineapple (Ananas comosus) industry and increase harvest costs. Pineapple flowering is thought to be triggered by increased ethylene levels and artificial forcing of pineapple flowering is a common practice to promote flowering synchronisation. However, little is known about the early hormonal and molecular changes of pineapple flowering induction and development. Here, we aimed to analyse the molecular, hormonal, and histological changes during artificial pineapple flowering by Ethrel ® 48 treatment. Histological analyses of the shoot apical meristem, leaf gibberellic acid (GA 3 ), and ethylene quantification were carried out during the first 72h after Ethrel ® 48 treatment. Expression profiles from ethylene biosynthesis (AcACS2 and AcACO1), gibberellin metabolism (AcGA2-ox1 and AcDELLA1), and flower development (FT-like gene (AcFT), LFY-like gene (AcLFY), and a PISTILLATA-like gene (AcPI)) genes were analysed during the first 24h after Ethrel ® 48 treatment. Differentiation processes of the shoot apical meristem into flower buds were already present in the first 72h after Ethrel ® 48 treatment. Ethrel ® 48 lead to a reduction in GA 3 levels, probably triggered by elevated ethylene levels and the positive regulation AcGA2-ox1. AcLFY activation upon Ethrel ® 48 may also have contributed to the reduction of GA 3 levels and, along with the up-regulation of AcPI, are probably associated with the flower induction activation. AcFT and AcDELLA1 do not seem to be regulated by GA 3 and ethylene. Decreased GA 3 and increased ethylene levels suggest an accumulation of AcDELLA1, which may display an important role in pineapple flowering induction. Thus, this study shows that molecular, hormonal, and histological changes are present right after Ethrel ® 48 treatment, providing new insights into how pineapple flowering occurs under natural conditions. Copyright © 2016 Elsevier GmbH. All rights reserved.

Cyanogenic Glucosides and Derivatives in Almond and Sweet Cherry Flower Buds from Dormancy to Flowering

PubMed Central

Del Cueto, Jorge; Ionescu, Irina A.; Pičmanová, Martina; Gericke, Oliver; Motawia, Mohammed S.; Olsen, Carl E.; Campoy, José A.; Dicenta, Federico; Møller, Birger L.; Sánchez-Pérez, Raquel

2017-01-01

Almond and sweet cherry are two economically important species of the Prunus genus. They both produce the cyanogenic glucosides prunasin and amygdalin. As part of a two-component defense system, prunasin and amygdalin release toxic hydrogen cyanide upon cell disruption. In this study, we investigated the potential role within prunasin and amygdalin and some of its derivatives in endodormancy release of these two Prunus species. The content of prunasin and of endogenous prunasin turnover products in the course of flower development was examined in five almond cultivars – differing from very early to extra-late in flowering time – and in one sweet early cherry cultivar. In all cultivars, prunasin began to accumulate in the flower buds shortly after dormancy release and the levels dropped again just before flowering time. In almond and sweet cherry, the turnover of prunasin coincided with increased levels of prunasin amide whereas prunasin anitrile pentoside and β-D-glucose-1-benzoate were abundant in almond and cherry flower buds at certain developmental stages. These findings indicate a role for the turnover of cyanogenic glucosides in controlling flower development in Prunus species. PMID:28579996

Sepal phenolic profile during Helleborus niger flower development.

PubMed

Schmitzer, Valentina; Mikulic-Petkovsek, Maja; Stampar, Franci

2013-11-01

Morphological changes and phenolic patterns of developing hellebore sepals and the effects of pistil removal on these parameters were studied by comparing six flower stages of Helleborus niger. Color changes were evaluated colorimetrically, chlorophyll content was measured spectrophotometrically, and anthocyanins and flavonols were identified and quantified with HPLC-MS. Pistil removal not only altered the morphological development of hellebore flower resulting in smaller flower and significant color changes but also lead to several biochemical modifications. Five cyanidin glycosides have been identified from the group of anthocyanins in hellebore. Individual and total anthocyanin content increased from bud to subsequent developmental stages. Moreover, significantly higher content levels of individual and total anthocyanins have been measured in non-pollinated flower sepals compared to sepals of pollinated flowers. From the group of flavonols eight quercetin and kaempferol compounds have been quantified in hellebore sepals. Flavonol content significantly decreased during flower development with lowest levels recorded in sepals of non-pollinated and senescent pollinated hellebore flowers. Sepals of pollinated flowers contained highest levels of chlorophyll and significantly lower amounts of chlorophyll were measured in non-pollinated flowers and in sepals of senescent stage. Copyright © 2013 Elsevier GmbH. All rights reserved.

Flower development in Arabidopsis: there is more to it than learning your ABCs.

PubMed

Prunet, Nathanaël; Jack, Thomas P

2014-01-01

The field of Arabidopsis flower development began in the early 1980s with the initial description of several mutants including apetala1, apetala2, and agamous that altered floral organ identity (Koornneef and van der Veen, Theor Appl Genet 58:257-263, 1980; Koornneef et al., J Hered 74:265-272, 1983). By the end of the 1980s, these mutants were receiving more focused attention to determine precisely how they affected flower development (Komaki et al., Development 104:195-203, 1988; Bowman et al., Plant Cell 1:37-52, 1989). In the last quarter century, impressive progress has been made in characterizing the gene products and molecular mechanisms that control the key events in flower development. In this review, we briefly summarize the highlights of work from the past 25 years but focus on advances in the field in the last several years.

Ectopic expression of Jatropha curcas APETALA1 (JcAP1) caused early flowering in Arabidopsis, but not in Jatropha

PubMed Central

Tang, Mingyong; Tao, Yan-Bin

2016-01-01

Jatropha curcas is a promising feedstock for biofuel production because Jatropha oil is highly suitable for the production of biodiesel and bio-jet fuels. However, Jatropha exhibits a low seed yield as a result of unreliable and poor flowering. APETALA1 (AP1) is a floral meristem and organ identity gene in higher plants. The flower meristem identity genes of Jatropha have not yet been identified or characterized. To better understand the genetic control of flowering in Jatropha, an AP1 homolog (JcAP1) was isolated from Jatropha. An amino acid sequence analysis of JcAP1 revealed a high similarity to the AP1 proteins of other perennial plants. JcAP1 was expressed in inflorescence buds, flower buds, sepals and petals. The highest expression level was observed during the early developmental stage of the flower buds. The overexpression of JcAP1 using the cauliflower mosaic virus (CaMV) 35S promoter resulted in extremely early flowering and abnormal flowers in transgenic Arabidopsis plants. Several flowering genes downstream of AP1 were up-regulated in the JcAP1-overexpressing transgenic plant lines. Furthermore, JcAP1 overexpression rescued the phenotype caused by the Arabidopsis AP1 loss-of-function mutant ap1-11. Therefore, JcAP1 is an ortholog of AtAP1, which plays a similar role in the regulation of flowering in Arabidopsis. However, the overexpression of JcAP1 in Jatropha using the same promoter resulted in little variation in the flowering time and floral organs, indicating that JcAP1 may be insufficient to regulate flowering by itself in Jatropha. This study helps to elucidate the function of JcAP1 and contributes to the understanding of the molecular mechanisms of flower development in Jatropha. PMID:27168978

Floral development at multiple spatial scales in Polygonum jucundum (Polygonaceae), a distylous species with broadly open flowers.

PubMed

Huang, Lan-Jie; Fu, Wen-Long; Wang, Xiao-Fan

2014-01-01

Distyly, a special polymorph, has evolved in many groups of angiosperms and has attracted attention since Darwin's time. Development studies on distylous taxa have helped us to understand the evolutionary process of this polymorph, but most of these studies focus on species with narrowly tubular corolla. Here, we studied the floral development of Polygonum jucundum, a distylous species with broadly open flowers, at multiple spatial scales. Results showed that the difference in stigma height between flowers of the two morphs was caused by differences in style growth throughout the entire floral development process. The observed difference in anther heights between the two morphs was because the filaments grew faster in short-styled (SS) than in long-styled (LS) flowers in the later stages of floral development. In addition, the longer styles in LS flowers than in SS flowers was because of faster cell division in the early stages of floral development. However, SS flowers had longer filaments than LS flowers primarily because of greater cell elongation. These results indicate that floral development in P. jucundum differs from that of distylous taxa with floral tubes shown in previous studies. Further, we conclude that the presence of distyly in species with open flowers is a result of convergent evolution.

DNA methylation/demethylation programming during peach flower bud dormancy release, development and blooming

USDA-ARS?s Scientific Manuscript database

Peach flower bud development undergoes a long, complex and temperature-dependent regulation process with cessation of growth in response to cool temperatures in late fall, a slow but gradual development during the chilling period in winter, and eventually blooming in early spring. It has been demon...

A genetic screen for modifiers of UFO meristem activity identifies three novel FUSED FLORAL ORGANS genes required for early flower development in Arabidopsis.

PubMed

Levin, J Z; Fletcher, J C; Chen, X; Meyerowitz, E M

1998-06-01

In a screen to identify novel genes required for early Arabidopsis flower development, we isolated four independent mutations that enhance the Ufo phenotype toward the production of filamentous structures in place of flowers. The mutants fall into three complementation groups, which we have termed FUSED FLORAL ORGANS (FFO) loci. ffo mutants have specific defects in floral organ separation and/or positioning; thus, the FFO genes identify components of a boundary formation mechanism(s) acting between developing floral organ primordia. FFO1 and FFO3 have specific functions in cauline leaf/stem separation and in first- and third-whorl floral organ separation, with FFO3 likely acting to establish and FFO1 to maintain floral organ boundaries. FFO2 acts at early floral stages to regulate floral organ number and positioning and to control organ separation within and between whorls. Plants doubly mutant for two ffo alleles display additive phenotypes, indicating that the FFO genes may act in separate pathways. Plants doubly mutant for an ffo gene and for ufo, lfy, or clv3 reveal that the FFO genes play roles related to those of UFO and LFY in floral meristem initiation and that FFO2 and FFO3 may act to control cell proliferation late in inflorescence development.

A genetic screen for modifiers of UFO meristem activity identifies three novel FUSED FLORAL ORGANS genes required for early flower development in Arabidopsis.

PubMed Central

Levin, J Z; Fletcher, J C; Chen, X; Meyerowitz, E M

1998-01-01

In a screen to identify novel genes required for early Arabidopsis flower development, we isolated four independent mutations that enhance the Ufo phenotype toward the production of filamentous structures in place of flowers. The mutants fall into three complementation groups, which we have termed FUSED FLORAL ORGANS (FFO) loci. ffo mutants have specific defects in floral organ separation and/or positioning; thus, the FFO genes identify components of a boundary formation mechanism(s) acting between developing floral organ primordia. FFO1 and FFO3 have specific functions in cauline leaf/stem separation and in first- and third-whorl floral organ separation, with FFO3 likely acting to establish and FFO1 to maintain floral organ boundaries. FFO2 acts at early floral stages to regulate floral organ number and positioning and to control organ separation within and between whorls. Plants doubly mutant for two ffo alleles display additive phenotypes, indicating that the FFO genes may act in separate pathways. Plants doubly mutant for an ffo gene and for ufo, lfy, or clv3 reveal that the FFO genes play roles related to those of UFO and LFY in floral meristem initiation and that FFO2 and FFO3 may act to control cell proliferation late in inflorescence development. PMID:9611175

Starch Turnover and Metabolism during Flower and Early Embryo Development1[CC-BY

PubMed Central

Pazmino, Diana; Gagliardini, Valeria

2016-01-01

The accumulation of starch within photosynthetic tissues and within dedicated storage organs has been characterized extensively in many species, and a function in buffering carbon availability or in fueling later growth phases, respectively, has been proposed. However, developmentally regulated starch turnover within heterotrophic tissues other than dedicated storage organs is poorly characterized, and its function is not well understood. Here, we report on the characterization of starch turnover during flower, early embryo, and silique development in Arabidopsis (Arabidopsis thaliana) using a combined clearing-staining technique on whole-mount tissue. Besides the two previously documented waves of transient starch accumulation in the stamen envelope, occurring during meiosis and pollen mitosis I, we identified a novel, third wave of starch amylogenesis/amylolysis during the last stages of stamen development. To gain insights into the underlying molecular mechanisms, we analyzed publicly available microarray data, which revealed a developmentally coordinated expression of carbohydrate transport and metabolism genes during these waves of transient starch accumulation. Based on this analysis, we characterized starch dynamics in mutants affecting hexose phosphate metabolism and translocation, and identified the Glc-6-phosphate/phosphate antiporter GPT1 as the putative translocator of Glc-6-phosphate for starch biosynthesis in reproductive tissues. Based on these results, we propose a model of starch synthesis within the pollen grain and discuss the nutrient transport route feeding the embryo within the developing seed. PMID:27794100

The role of WOX genes in flower development

PubMed Central

Costanzo, Enrico; Trehin, Christophe; Vandenbussche, Michiel

2014-01-01

Background WOX (Wuschel-like homeobOX) genes form a family of plant-specific HOMEODOMAIN transcription factors, the members of which play important developmental roles in a diverse range of processes. WOX genes were first identified as determining cell fate during embryo development, as well as playing important roles in maintaining stem cell niches in the plant. In recent years, new roles have been identified in plant architecture and organ development, particularly at the flower level. Scope In this review, the role of WOX genes in flower development and flower architecture is highlighted, as evidenced from data obtained in the last few years. The roles played by WOX genes in different species and different flower organs are compared, and differential functional recruitment of WOX genes during flower evolution is considered. Conclusions This review compares available data concerning the role of WOX genes in flower and organ architecture among different species of angiosperms, including representatives of monocots and eudicots (rosids and asterids). These comparative data highlight the usefulness of the WOX gene family for evo–devo studies of floral development. PMID:24973416

Flowering after disaster: Early Danian buckthorn (Rhamnaceae) flowers and leaves from Patagonia

PubMed Central

Gandolfo, Maria A.; Iglesias, Ari; Wilf, Peter

2017-01-01

Southern-Hemisphere terrestrial communities from the early Paleocene are poorly known, but recent work on Danian plant fossils from the Salamanca Formation in Chubut Province, Argentina are providing critical data on earliest Paleocene floras. The fossils described here come from a site in the Salamanca Formation dating to ca. 1 million years or less after the end-Cretaceous extinction event; they are the first fossil flowers reported from the Danian of South America, and possible the entire Southern Hemisphere. They are compressions and impressions in flat-laminated light gray shale, and they belong to the family Rhamnaceae (buckthorns). Flowers of Notiantha grandensis gen. et sp. nov. are pentamerous, with distinctly keeled calyx lobes projecting from the hypanthium, clawed and cucullate emarginate petals, antepetalous stamens, and a pentagonal floral disk that fills the hypanthium. Their phylogenetic position was evaluated using a molecular scaffold approach combined with morphological data. Results indicate that the flowers are most like those of extant ziziphoid Rhamnaceae. The associated leaves, assigned to Suessenia grandensis gen. et sp. nov. are simple and ovate, with serrate margins and three acrodromous basal veins. They conform to the distinctive leaves of some extant Rhamnaceae in the ziziphoid and ampelozizyphoid clades. These fossils provide the first unequivocal megafossil evidence of Rhamnaceae in the Southern Hemisphere, demonstrating that Rhamnaceae expanded beyond the tropics by the earliest Paleocene. Given previous reports of rhamnaceous pollen in the late Paleogene and Neogene of Antarctica and southern Australia, this new occurrence increases the possibility of high-latitude dispersal of this family between South America and Australia via Antarctica during the Cenozoic. PMID:28489895

Volatile Organic Compounds Emissions from Luculia pinceana Flower and Its Changes at Different Stages of Flower Development.

PubMed

Li, Yuying; Ma, Hong; Wan, Youming; Li, Taiqiang; Liu, Xiuxian; Sun, Zhenghai; Li, Zhenghong

2016-04-22

Luculia plants are famed ornamental plants with sweetly fragrant flowers, of which L. pinceana Hooker, found primarily in Yunnan Province, China, has the widest distribution. Solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) was employed to identify the volatile organic compounds (VOCs) emitted from different flower development stages of L. pinceana for the evaluation of floral volatile polymorphism. Peak areas were normalized as percentages and used to determine the relative amounts of the volatiles. The results showed that a total of 39 compounds were identified at four different stages of L. pinceana flower development, including 26 at the bud stage, 26 at the initial-flowering stage, 32 at the full-flowering stage, and 32 at the end-flowering stage. The most abundant compound was paeonol (51%-83%) followed by (E,E)-α-farnesene, cyclosativene, and δ-cadinene. All these volatile compounds create the unique fragrance of L. pinceana flower. Floral scent emission offered tendency of ascending first and descending in succession, meeting its peak level at the initial-flowering stage. The richest diversity of floral volatile was detected at the third and later periods of flower development. Principal component analysis (PCA) indicated that the composition and its relative content of floral scent differed throughout the whole flower development. The result has important implications for future floral fragrance breeding of Luculia. L. pinceana would be adequate for a beneficial houseplant and has a promising prospect for development as essential oil besides for a fragrant ornamental owing to the main compounds of floral scent with many medicinal properties.

[LEAFY, a master regulator of flower development].

PubMed

Vachon, Gilles; Tichtinsky, Gabrielle; Parcy, François

2012-01-01

Flowering plants or angiosperms constitute the vast majority of plant species. Their evolutionary success is largely due to the efficiency of the flower as reproductive structure. Work performed on model plant species in the last 20 years has identified the LEAFY gene as a key regulator of flower development. LEAFY is a unique plant transcription factor responsible for the formation of the earliest floral stage as well as for the induction of homeotic genes triggering floral organ determination. But LEAFY is also present in non-flowering plants such as mosses, ferns and gymnosperms. Recent studies suggest that LEAFY might play a role in cell division and meristem development in basal plants, a function that is probably more ancestral than the later acquired floral function. Analyzing the evolution of the role and the biochemical properties of this peculiar regulator starts to shade light on the mysterious origin of flowering plants. © Société de Biologie, 2012.

Overexpression of a flower-specific aerolysin-like protein from the dioecious plant Rumex acetosa alters flower development and induces male sterility in transgenic tobacco.

PubMed

Manzano, Susana; Megías, Zoraida; Martínez, Cecilia; García, Alicia; Aguado, Encarnación; Chileh, Tarik; López-Alonso, Diego; García-Maroto, Federico; Kejnovský, Eduard; Široký, Jiří; Kubát, Zdeněk; Králová, Tereza; Vyskot, Boris; Jamilena, Manuel

2017-01-01

Sex determination in Rumex acetosa, a dioecious plant with a complex XY 1 Y 2 sex chromosome system (females are XX and males are XY 1 Y 2 ), is not controlled by an active Y chromosome but depends on the ratio between the number of X chromosomes and autosomes. To gain insight into the molecular mechanisms of sex determination, we generated a subtracted cDNA library enriched in genes specifically or predominantly expressed in female floral buds in early stages of development, when sex determination mechanisms come into play. In the present paper, we report the molecular and functional characterization of FEM32, a gene encoding a protein that shares a common architecture with proteins in different plants, animals, bacteria and fungi of the aerolysin superfamily; many of these function as β pore-forming toxins. The expression analysis, assessed by northern blot, RT-PCR and in situ hybridization, demonstrates that this gene is specifically expressed in flowers in both early and late stages of development, although its transcripts accumulate much more in female flowers than in male flowers. The ectopic expression of FEM32 under both the constitutive promoter 35S and the flower-specific promoter AP3 in transgenic tobacco showed no obvious alteration in vegetative development but was able to alter floral organ growth and pollen fertility. The 35S::FEM32 and AP3::FEM32 transgenic lines showed a reduction in stamen development and pollen viability, as well as a diminution in fruit set, fruit development and seed production. Compared with other floral organs, pistil development was, however, enhanced in plants overexpressing FEM32. According to these effects, it is likely that FEM32 functions in Rumex by arresting stamen and pollen development during female flower development. The aerolysin-like pore-forming proteins of eukaryotes are mainly involved in defence mechanisms against bacteria, fungi and insects and are also involved in apoptosis and programmed cell death (PCD

Current trends and future directions in flower development research

PubMed Central

Scutt, Charlie P.; Vandenbussche, Michiel

2014-01-01

Flowers, the reproductive structures of the approximately 400 000 extant species of flowering plants, exist in a tremendous range of forms and sizes, mainly due to developmental differences involving the number, arrangement, size and form of the floral organs of which they consist. However, this tremendous diversity is underpinned by a surprisingly robust basic floral structure in which a central group of carpels forms on an axis of determinate growth, almost invariably surrounded by two successive zones containing stamens and perianth organs, respectively. Over the last 25 years, remarkable progress has been achieved in describing the molecular mechanisms that control almost all aspects of flower development, from the phase change that initiates flowering to the final production of fruits and seeds. However, this work has been performed almost exclusively in a small number of eudicot model species, chief among which is Arabidopsis thaliana. Studies of flower development must now be extended to a much wider phylogenetic range of flowering plants and, indeed, to their closest living relatives, the gymnosperms. Studies of further, more wide-ranging models should provide insights that, for various reasons, cannot be obtained by studying the major existing models alone. The use of further models should also help to explain how the first flowering plants evolved from an unknown, although presumably gymnosperm-like ancestor, and rapidly diversified to become the largest major plant group and to dominate the terrestrial flora. The benefits for society of a thorough understanding of flower development are self-evident, as human life depends to a large extent on flowering plants and on the fruits and seeds they produce. In this preface to the Special Issue, we introduce eleven articles on flower development, representing work in both established and further models, including gymnosperms. We also present some of our own views on current trends and future directions of the

The role of WOX genes in flower development.

PubMed

Costanzo, Enrico; Trehin, Christophe; Vandenbussche, Michiel

2014-11-01

WOX (Wuschel-like homeobOX) genes form a family of plant-specific HOMEODOMAIN transcription factors, the members of which play important developmental roles in a diverse range of processes. WOX genes were first identified as determining cell fate during embryo development, as well as playing important roles in maintaining stem cell niches in the plant. In recent years, new roles have been identified in plant architecture and organ development, particularly at the flower level. In this review, the role of WOX genes in flower development and flower architecture is highlighted, as evidenced from data obtained in the last few years. The roles played by WOX genes in different species and different flower organs are compared, and differential functional recruitment of WOX genes during flower evolution is considered. This review compares available data concerning the role of WOX genes in flower and organ architecture among different species of angiosperms, including representatives of monocots and eudicots (rosids and asterids). These comparative data highlight the usefulness of the WOX gene family for evo-devo studies of floral development. © The Author 2014. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Current trends and future directions in flower development research.

PubMed

Scutt, Charlie P; Vandenbussche, Michiel

2014-11-01

Flowers, the reproductive structures of the approximately 400 000 extant species of flowering plants, exist in a tremendous range of forms and sizes, mainly due to developmental differences involving the number, arrangement, size and form of the floral organs of which they consist. However, this tremendous diversity is underpinned by a surprisingly robust basic floral structure in which a central group of carpels forms on an axis of determinate growth, almost invariably surrounded by two successive zones containing stamens and perianth organs, respectively. Over the last 25 years, remarkable progress has been achieved in describing the molecular mechanisms that control almost all aspects of flower development, from the phase change that initiates flowering to the final production of fruits and seeds. However, this work has been performed almost exclusively in a small number of eudicot model species, chief among which is Arabidopsis thaliana. Studies of flower development must now be extended to a much wider phylogenetic range of flowering plants and, indeed, to their closest living relatives, the gymnosperms. Studies of further, more wide-ranging models should provide insights that, for various reasons, cannot be obtained by studying the major existing models alone. The use of further models should also help to explain how the first flowering plants evolved from an unknown, although presumably gymnosperm-like ancestor, and rapidly diversified to become the largest major plant group and to dominate the terrestrial flora. The benefits for society of a thorough understanding of flower development are self-evident, as human life depends to a large extent on flowering plants and on the fruits and seeds they produce. In this preface to the Special Issue, we introduce eleven articles on flower development, representing work in both established and further models, including gymnosperms. We also present some of our own views on current trends and future directions of the

Over-Expression of GmGIa-Regulated Soybean miR172a Confers Early Flowering in Transgenic Arabidopsis thaliana.

PubMed

Wang, Tao; Sun, Ming-Yang; Wang, Xue-Song; Li, Wen-Bin; Li, Yong-Guang

2016-04-29

Flowering is a pivotal event in the life cycle of plants. miR172 has been widely confirmed to play critical roles in flowering time control by regulating its target gene expression in Arabidopsis. However, the role of its counterpart in soybean remains largely unclear. In the present study, we found that the gma-miR172a was regulated by a GIGANTEA ortholog, GmGIa, in soybean through miRNA metabolism. The expression analysis revealed that gma-miR172a has a pattern of diurnal rhythm expression and its abundance increased rapidly as plants grew until the initiation of flowering phase in soybean. One target gene of gma-miR172a, Glyma03g33470, was predicted and verified using a modified RLM 5'-RACE (RNA ligase-mediated rapid amplification of 5' cDNA ends) assay. Overexpression of gma-miR172a exhibited an early flowering phenotype and the expression of FT, AP1 and LFY were simultaneously increased in gma-miR172a-transgenic Arabidopsis plants, suggesting that the early flowering phenotype was associated with up-regulation of these genes. The overexpression of the gma-miR172a-resistant version of Glyma03g33470 weakened early flowering phenotype in the toe1 mutant of Arabidopsis. Taken together, our results suggested that gma-miR172a played an important role in GmGIa-mediated flowering by repressing Glyma03g33470, which in turn increased the expression of FT, AP1 and LFY to promote flowering in soybean.

Flower development: open questions and future directions.

PubMed

Wellmer, Frank; Bowman, John L; Davies, Brendan; Ferrándiz, Cristina; Fletcher, Jennifer C; Franks, Robert G; Graciet, Emmanuelle; Gregis, Veronica; Ito, Toshiro; Jack, Thomas P; Jiao, Yuling; Kater, Martin M; Ma, Hong; Meyerowitz, Elliot M; Prunet, Nathanaël; Riechmann, José Luis

2014-01-01

Almost three decades of genetic and molecular analyses have resulted in detailed insights into many of the processes that take place during flower development and in the identification of a large number of key regulatory genes that control these processes. Despite this impressive progress, many questions about how flower development is controlled in different angiosperm species remain unanswered. In this chapter, we discuss some of these open questions and the experimental strategies with which they could be addressed. Specifically, we focus on the areas of floral meristem development and patterning, floral organ specification and differentiation, as well as on the molecular mechanisms underlying the evolutionary changes that have led to the astounding variations in flower size and architecture among extant and extinct angiosperms.

Differential contribution of two Ppd-1 homoeoalleles to early-flowering phenotype in Nepalese and Japanese varieties of common wheat.

PubMed

Nguyen, Anh T; Iehisa, Julio C M; Mizuno, Nobuyuki; Nitta, Miyuki; Nasuda, Shuhei; Takumi, Shigeo

2013-12-01

Wheat landraces carry abundant genetic variation in heading and flowering times. Here, we studied flowering-related traits of two Nepalese varieties, KU-4770 and KU-180 and a Japanese wheat cultivar, Shiroganekomugi (SGK). These three wheat varieties showed similar flowering time in a common garden experiment. In total, five significant quantitative trait loci (QTLs) for three examined traits, the heading, flowering and maturation times, were detected using an F2 population of SGK/KU-4770. The QTLs were found at the Ppd-1 loci on chromosomes 2B and 2D and the 2B QTL was also confirmed in another F2 population of SGK/KU-180. The Ppd-D1 allele from SGK and the Ppd-B1 alleles from the two Nepalese varieties might be causal for early-flowering phenotype. The SGK Ppd-D1 allele contained a 2-kb deletion in the 5' upstream region, indicating a photoperiod-insensitive Ppd-D1a allele. Real-time PCR analysis estimating the Ppd-B1 copy number revealed that the two Nepalese varieties included two intact Ppd-B1 copies, putatively resulting in photoperiod insensitivity and an early-flowering phenotype. The two photoperiod-insensitive Ppd-1 homoeoalleles could independently contribute to segregation of early-flowering individuals in the two F2 populations. Therefore, wheat landraces are genetic resources for discovery of alleles useful for improving wheat heading or flowering times.

Differential contribution of two Ppd-1 homoeoalleles to early-flowering phenotype in Nepalese and Japanese varieties of common wheat

PubMed Central

Nguyen, Anh T.; Iehisa, Julio C. M.; Mizuno, Nobuyuki; Nitta, Miyuki; Nasuda, Shuhei; Takumi, Shigeo

2013-01-01

Wheat landraces carry abundant genetic variation in heading and flowering times. Here, we studied flowering-related traits of two Nepalese varieties, KU-4770 and KU-180 and a Japanese wheat cultivar, Shiroganekomugi (SGK). These three wheat varieties showed similar flowering time in a common garden experiment. In total, five significant quantitative trait loci (QTLs) for three examined traits, the heading, flowering and maturation times, were detected using an F2 population of SGK/KU-4770. The QTLs were found at the Ppd-1 loci on chromosomes 2B and 2D and the 2B QTL was also confirmed in another F2 population of SGK/KU-180. The Ppd-D1 allele from SGK and the Ppd-B1 alleles from the two Nepalese varieties might be causal for early-flowering phenotype. The SGK Ppd-D1 allele contained a 2-kb deletion in the 5′ upstream region, indicating a photoperiod-insensitive Ppd-D1a allele. Real-time PCR analysis estimating the Ppd-B1 copy number revealed that the two Nepalese varieties included two intact Ppd-B1 copies, putatively resulting in photoperiod insensitivity and an early-flowering phenotype. The two photoperiod-insensitive Ppd-1 homoeoalleles could independently contribute to segregation of early-flowering individuals in the two F2 populations. Therefore, wheat landraces are genetic resources for discovery of alleles useful for improving wheat heading or flowering times. PMID:24399909

qEMF3, a novel QTL for the early-morning flowering trait from wild rice, Oryza officinalis, to mitigate heat stress damage at flowering in rice, O. sativa

PubMed Central

Hirabayashi, Hideyuki; Sasaki, Kazuhiro; Kambe, Takashi; Gannaban, Ritchel B.; Miras, Monaliza A.; Mendioro, Merlyn S.; Simon, Eliza V.; Lumanglas, Patrick D.; Fujita, Daisuke; Takemoto-Kuno, Yoko; Takeuchi, Yoshinobu; Kaji, Ryota; Kondo, Motohiko; Kobayashi, Nobuya; Ogawa, Tsugufumi; Ando, Ikuo; Jagadish, Krishna S. V.; Ishimaru, Tsutomu

2015-01-01

A decline in rice (Oryza sativa L.) production caused by heat stress is one of the biggest concerns resulting from future climate change. Rice spikelets are most susceptible to heat stress at flowering. The early-morning flowering (EMF) trait mitigates heat-induced spikelet sterility at the flowering stage by escaping heat stress during the daytime. We attempted to develop near-isogenic lines (NILs) for EMF in the indica-type genetic background by exploiting the EMF locus from wild rice, O. officinalis (CC genome). A stable quantitative trait locus (QTL) for flower opening time (FOT) was detected on chromosome 3. A QTL was designated as qEMF3 and it shifted FOT by 1.5–2.0h earlier for cv. Nanjing 11 in temperate Japan and cv. IR64 in the Philippine tropics. NILs for EMF mitigated heat-induced spikelet sterility under elevated temperature conditions completing flower opening before reaching 35°C, a general threshold value leading to spikelet sterility. Quantification of FOT of cultivars popular in the tropics and subtropics did not reveal the EMF trait in any of the cultivars tested, suggesting that qEMF3 has the potential to advance FOT of currently popular cultivars to escape heat stress at flowering under future hotter climates. This is the first report to examine rice with the EMF trait through marker-assisted breeding using wild rice as a genetic resource. PMID:25534925

Overexpression of BpAP1 induces early flowering and produces dwarfism in Betula platyphylla × Betula pendula.

PubMed

Huang, Haijiao; Wang, Shan; Jiang, Jing; Liu, Guifeng; Li, Huiyu; Chen, Su; Xu, Huanwen

2014-08-01

The involvement of APETALA1 (AP1) in the flowering transition has been the focus of much research. Here, we produced Betula platyphylla × Betula pendula (birch) lines that overexpressed BpAP1 using Agrobacterium-mediated transformation; we obtained five independent 35S::BpAP1 transgenic lines. Polymerase chain reaction (PCR), Southern, northern and western analyses were used to identify the transformants. As determined by quantitative real-time PCR (qRT-PCR), BpAP1 expression in roots, shoots, leaves and terminal buds of 35S::BpAP1 transgenic lines was significantly higher than that in the wild type (WT, P < 0.01). The average height of 2-year-old 35S::BpAP1 plants was significantly lower (41.17%) than that of non-transgenic plants. In the 35S::BpAP1 lines, inflorescences emerged successively beginning 2 months after transplanting. In addition, the length-diameter ratio of fully developed male and female inflorescences were both significantly less than those of the WT (P < 0.05), i.e. the morphological characteristic was stubby. The male inflorescences emerged early, with empty, draped anthers, and pollen was rarely produced, whereas the female floret structure was not different from WT. The pistils developed normally and could accept pollen, leading to the production of hybrid progeny (F1 ). F1 plants completed flowering within only 1 year after sowing. We demonstrate that BpAP1 can be inherited through sexual reproduction. Overexpression of BpAP1 caused early flowering and dwarfism; these lines had an obviously shortened juvenile phase. These results greatly increase our understanding of the mechanisms underlying the flowering transition and enhance genetic studies of birch traits, and they open up new possibilities for the breeding of birch and other woody plants. © 2013 Scandinavian Plant Physiology Society.

Short-term effects of burn season on flowering phenology of savanna plants

USGS Publications Warehouse

Pavlovic, N.B.; Leicht-Young, S. A.; Grundel, R.

2011-01-01

We examined the effect of season of burn on flowering phenology of groundlayer species, in the year following burns, in a mesic-sand Midwestern oak savanna. Burn treatments were fall, early-season, growing-season, late-season, and 1 or 5 years after a prior early-season wildfire. For these treatments, we compared the number of flowering stems and of flowers for species overall, for the 20 most prolifically flowering species, as well as for species grouped by flowering phenoperiods, and by growth form. Growing-season burn had a significant negative effect on number of flowering stems and total number of flowers. This effect occurred when either the burn occurred during the flowering season or during the season prior to the flowering phenoperiod. Tradescantia ohiensis showed expedited flowering and Phlox pilosa showed delayed flowering in response to early-season burning. Flowering of early shrubs was reduced by the previous fall and early-spring fires, while flowering of mid-season blooming shrubs was reduced by the early- and growing-season burns. Vaccinium and Gaylussacia, early-flowering shrubs, produced fewer flowers 1 year after than 5 years after an early-season burn. Arabis lyrata showed reduced flowering from the early-season burn. We also found four instances where the early-spring burn effect on flowering was more severe than the fall burn effect, suggesting that many frequent early-season burns may be deleterious to flowering and reproduction of some species. Burns occurring too frequently in the same season could negatively affect future flowering and reproduction of these plant species.

S-LOCUS EARLY FLOWERING 3 Is Exclusively Present in the Genomes of Short-Styled Buckwheat Plants that Exhibit Heteromorphic Self-Incompatibility

PubMed Central

Aii, Jotaro; Abe, Tomoko; Matsumoto, Daiki; Sato, Shingo; Hayashi, Yoriko; Ohnishi, Ohmi; Ota, Tatsuya

2012-01-01

The different forms of flowers in a species have attracted the attention of many evolutionary biologists, including Charles Darwin. In Fagopyrum esculentum (common buckwheat), the occurrence of dimorphic flowers, namely short-styled and long-styled flowers, is associated with a type of self-incompatibility (SI) called heteromorphic SI. The floral morphology and intra-morph incompatibility are both determined by a single genetic locus named the S-locus. Plants with short-styled flowers are heterozygous (S/s) and plants with long-styled flowers are homozygous recessive (s/s) at the S-locus. Despite recent progress in our understanding of the molecular basis of flower development and plant SI systems, the molecular mechanisms underlying heteromorphic SI remain unresolved. By examining differentially expressed genes from the styles of the two floral morphs, we identified a gene that is expressed only in short-styled plants. The novel gene identified was completely linked to the S-locus in a linkage analysis of 1,373 plants and had homology to EARLY FLOWERING 3. We named this gene S-LOCUS EARLY FLOWERING 3 (S-ELF3). In an ion-beam-induced mutant that harbored a deletion in the genomic region spanning S-ELF3, a phenotype shift from short-styled flowers to long-styled flowers was observed. Furthermore, S-ELF3 was present in the genome of short-styled plants and absent from that of long-styled plants both in world-wide landraces of buckwheat and in two distantly related Fagopyrum species that exhibit heteromorphic SI. Moreover, independent disruptions of S-ELF3 were detected in a recently emerged self-compatible Fagopyrum species and a self-compatible line of buckwheat. The nonessential role of S-ELF3 in the survival of individuals and the prolonged evolutionary presence only in the genomes of short-styled plants exhibiting heteromorphic SI suggests that S-ELF3 is a suitable candidate gene for the control of the short-styled phenotype of buckwheat plants. PMID:22312442

Goethe and the ABC model of flower development.

PubMed

Coen, E

2001-06-01

About 10 years ago, the ABC model for the genetic control of flower development was proposed. This model was initially based on the analysis of mutant flowers but has subsequently been confirmed by molecular analysis. This paper describes the 200-year history behind this model, from the late 18th century when Goethe arrived at his idea of plant metamorphosis, to the genetic studies on flower mutants carried out on Arabidopsis and Antirrhinum in the late 20th century.

Record-Breaking Early Flowering in the Eastern United States

PubMed Central

Ellwood, Elizabeth R.; Temple, Stanley A.; Primack, Richard B.; Davis, Charles C.

2013-01-01

Flowering times are well-documented indicators of the ecological effects of climate change and are linked to numerous ecosystem processes and trophic interactions. Dozens of studies have shown that flowering times for many spring-flowering plants have become earlier as a result of recent climate change, but it is uncertain if flowering times will continue to advance as temperatures rise. Here, we used long-term flowering records initiated by Henry David Thoreau in 1852 and Aldo Leopold in 1935 to investigate this question. Our analyses demonstrate that record-breaking spring temperatures in 2010 and 2012 in Massachusetts, USA, and 2012 in Wisconsin, USA, resulted in the earliest flowering times in recorded history for dozens of spring-flowering plants of the eastern United States. These dramatic advances in spring flowering were successfully predicted by historical relationships between flowering and spring temperature spanning up to 161 years of ecological change. These results demonstrate that numerous temperate plant species have yet to show obvious signs of physiological constraints on phenological advancement in the face of climate change. PMID:23342001

Perigone Lobe Transcriptome Analysis Provides Insights into Rafflesia cantleyi Flower Development.

PubMed

Lee, Xin-Wei; Mat-Isa, Mohd-Noor; Mohd-Elias, Nur-Atiqah; Aizat-Juhari, Mohd Afiq; Goh, Hoe-Han; Dear, Paul H; Chow, Keng-See; Haji Adam, Jumaat; Mohamed, Rahmah; Firdaus-Raih, Mohd; Wan, Kiew-Lian

2016-01-01

Rafflesia is a biologically enigmatic species that is very rare in occurrence and possesses an extraordinary morphology. This parasitic plant produces a gigantic flower up to one metre in diameter with no leaves, stem or roots. However, little is known about the floral biology of this species especially at the molecular level. In an effort to address this issue, we have generated and characterised the transcriptome of the Rafflesia cantleyi flower, and performed a comparison with the transcriptome of its floral bud to predict genes that are expressed and regulated during flower development. Approximately 40 million sequencing reads were generated and assembled de novo into 18,053 transcripts with an average length of 641 bp. Of these, more than 79% of the transcripts had significant matches to annotated sequences in the public protein database. A total of 11,756 and 7,891 transcripts were assigned to Gene Ontology categories and clusters of orthologous groups respectively. In addition, 6,019 transcripts could be mapped to 129 pathways in Kyoto Encyclopaedia of Genes and Genomes Pathway database. Digital abundance analysis identified 52 transcripts with very high expression in the flower transcriptome of R. cantleyi. Subsequently, analysis of differential expression between developing flower and the floral bud revealed a set of 105 transcripts with potential role in flower development. Our work presents a deep transcriptome resource analysis for the developing flower of R. cantleyi. Genes potentially involved in the growth and development of the R. cantleyi flower were identified and provide insights into biological processes that occur during flower development.

Transcriptomic analysis of flower development in wintersweet (Chimonanthus praecox).

PubMed

Liu, Daofeng; Sui, Shunzhao; Ma, Jing; Li, Zhineng; Guo, Yulong; Luo, Dengpan; Yang, Jianfeng; Li, Mingyang

2014-01-01

Wintersweet (Chimonanthus praecox) is familiar as a garden plant and woody ornamental flower. On account of its unique flowering time and strong fragrance, it has a high ornamental and economic value. Despite a long history of human cultivation, our understanding of wintersweet genetics and molecular biology remains scant, reflecting a lack of basic genomic and transcriptomic data. In this study, we assembled three cDNA libraries, from three successive stages in flower development, designated as the flower bud with displayed petal, open flower and senescing flower stages. Using the Illumina RNA-Seq method, we obtained 21,412,928, 26,950,404, 24,912,954 qualified Illumina reads, respectively, for the three successive stages. The pooled reads from all three libraries were then assembled into 106,995 transcripts, 51,793 of which were annotated in the NCBI non-redundant protein database. Of these annotated sequences, 32,649 and 21,893 transcripts were assigned to gene ontology categories and clusters of orthologous groups, respectively. We could map 15,587 transcripts onto 312 pathways using the Kyoto Encyclopedia of Genes and Genomes pathway database. Based on these transcriptomic data, we obtained a large number of candidate genes that were differentially expressed at the open flower and senescing flower stages. An analysis of differentially expressed genes involved in plant hormone signal transduction pathways indicated that although flower opening and senescence may be independent of the ethylene signaling pathway in wintersweet, salicylic acid may be involved in the regulation of flower senescence. We also succeeded in isolating key genes of floral scent biosynthesis and proposed a biosynthetic pathway for monoterpenes and sesquiterpenes in wintersweet flowers, based on the annotated sequences. This comprehensive transcriptomic analysis presents fundamental information on the genes and pathways which are involved in flower development in wintersweet. And our data

Transcriptomic Analysis of Flower Development in Wintersweet (Chimonanthus praecox)

PubMed Central

Liu, Daofeng; Sui, Shunzhao; Ma, Jing; Li, Zhineng; Guo, Yulong; Luo, Dengpan; Yang, Jianfeng; Li, Mingyang

2014-01-01

Wintersweet (Chimonanthus praecox) is familiar as a garden plant and woody ornamental flower. On account of its unique flowering time and strong fragrance, it has a high ornamental and economic value. Despite a long history of human cultivation, our understanding of wintersweet genetics and molecular biology remains scant, reflecting a lack of basic genomic and transcriptomic data. In this study, we assembled three cDNA libraries, from three successive stages in flower development, designated as the flower bud with displayed petal, open flower and senescing flower stages. Using the Illumina RNA-Seq method, we obtained 21,412,928, 26,950,404, 24,912,954 qualified Illumina reads, respectively, for the three successive stages. The pooled reads from all three libraries were then assembled into 106,995 transcripts, 51,793 of which were annotated in the NCBI non-redundant protein database. Of these annotated sequences, 32,649 and 21,893 transcripts were assigned to gene ontology categories and clusters of orthologous groups, respectively. We could map 15,587 transcripts onto 312 pathways using the Kyoto Encyclopedia of Genes and Genomes pathway database. Based on these transcriptomic data, we obtained a large number of candidate genes that were differentially expressed at the open flower and senescing flower stages. An analysis of differentially expressed genes involved in plant hormone signal transduction pathways indicated that although flower opening and senescence may be independent of the ethylene signaling pathway in wintersweet, salicylic acid may be involved in the regulation of flower senescence. We also succeeded in isolating key genes of floral scent biosynthesis and proposed a biosynthetic pathway for monoterpenes and sesquiterpenes in wintersweet flowers, based on the annotated sequences. This comprehensive transcriptomic analysis presents fundamental information on the genes and pathways which are involved in flower development in wintersweet. And our data

qEMF3, a novel QTL for the early-morning flowering trait from wild rice, Oryza officinalis, to mitigate heat stress damage at flowering in rice, O. sativa.

PubMed

Hirabayashi, Hideyuki; Sasaki, Kazuhiro; Kambe, Takashi; Gannaban, Ritchel B; Miras, Monaliza A; Mendioro, Merlyn S; Simon, Eliza V; Lumanglas, Patrick D; Fujita, Daisuke; Takemoto-Kuno, Yoko; Takeuchi, Yoshinobu; Kaji, Ryota; Kondo, Motohiko; Kobayashi, Nobuya; Ogawa, Tsugufumi; Ando, Ikuo; Jagadish, Krishna S V; Ishimaru, Tsutomu

2015-03-01

A decline in rice (Oryza sativa L.) production caused by heat stress is one of the biggest concerns resulting from future climate change. Rice spikelets are most susceptible to heat stress at flowering. The early-morning flowering (EMF) trait mitigates heat-induced spikelet sterility at the flowering stage by escaping heat stress during the daytime. We attempted to develop near-isogenic lines (NILs) for EMF in the indica-type genetic background by exploiting the EMF locus from wild rice, O. officinalis (CC genome). A stable quantitative trait locus (QTL) for flower opening time (FOT) was detected on chromosome 3. A QTL was designated as qEMF3 and it shifted FOT by 1.5-2.0 h earlier for cv. Nanjing 11 in temperate Japan and cv. IR64 in the Philippine tropics. NILs for EMF mitigated heat-induced spikelet sterility under elevated temperature conditions completing flower opening before reaching 35°C, a general threshold value leading to spikelet sterility. Quantification of FOT of cultivars popular in the tropics and subtropics did not reveal the EMF trait in any of the cultivars tested, suggesting that qEMF3 has the potential to advance FOT of currently popular cultivars to escape heat stress at flowering under future hotter climates. This is the first report to examine rice with the EMF trait through marker-assisted breeding using wild rice as a genetic resource. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Photosynthate partitioning during flowering in relation to senescence of spinach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sklensky, D.; Davies, P.J.

1990-05-01

Male spinach plants are frequently cited as a counter-example to the nutrient drain hypothesis. Photosynthate partitioning in both male and female plants was examined. Leaves just below the inflorescences in plants at various stages of flowering were labelled with {sup 14}CO{sub 2} and the photosynthate allowed to partition for three hours. The leaves, flowers and stems of the inflorescence, and the other above ground vegetative tissue were harvested. These parts were combusted in a sample oxidizer for the collection of the {sup 14}CO{sub 2}. Allocation to the male and female flowers at very early stages are similar. As the flowersmore » develop further, male flowers receive more photosynthate than do female flowers in early fruit production. Thus it is possible that nutrient drain to the flowers in male spinach plants is sufficient to account for senescence.« less

Domestication-driven Gossypium profilin 1 (GhPRF1) gene transduces early flowering phenotype in tobacco by spatial alteration of apical/floral-meristem related gene expression.

PubMed

Pandey, Dhananjay K; Chaudhary, Bhupendra

2016-05-13

Plant profilin genes encode core cell-wall structural proteins and are evidenced for their up-regulation under cotton domestication. Notwithstanding striking discoveries in the genetics of cell-wall organization in plants, little is explicit about the manner in which profilin-mediated molecular interplay and corresponding networks are altered, especially during cellular signalling of apical meristem determinacy and flower development. Here we show that the ectopic expression of GhPRF1 gene in tobacco resulted in the hyperactivation of apical meristem and early flowering phenotype with increased flower number in comparison to the control plants. Spatial expression alteration in CLV1, a key meristem-determinacy gene, is induced by the GhPRF1 overexpression in a WUS-dependent manner and mediates cell signalling to promote flowering. But no such expression alterations are recorded in the GhPRF1-RNAi lines. The GhPRF1 transduces key positive flowering regulator AP1 gene via coordinated expression of FT4, SOC1, FLC1 and FT1 genes involved in the apical-to-floral meristem signalling cascade which is consistent with our in silico profilin interaction data. Remarkably, these positive and negative flowering regulators are spatially controlled by the Actin-Related Protein (ARP) genes, specifically ARP4 and ARP6 in proximate association with profilins. This study provides a novel and systematic link between GhPRF1 gene expression and the flower primordium initiation via up-regulation of the ARP genes, and an insight into the functional characterization of GhPRF1 gene acting upstream to the flowering mechanism. Also, the transgenic plants expressing GhPRF1 gene show an increase in the plant height, internode length, leaf size and plant vigor. Overexpression of GhPRF1 gene induced early and increased flowering in tobacco with enhanced plant vigor. During apical meristem determinacy and flower development, the GhPRF1 gene directly influences key flowering regulators through ARP

Recent advances in the research and development of blue flowers.

PubMed

Noda, Naonobu

2018-01-01

Flower color is the most important trait in the breeding of ornamental plants. In the floriculture industry, however, bluish colored flowers of desirable plants have proved difficult to breed. Many ornamental plants with a high production volume, such as rose and chrysanthemum, lack the key genes for producing the blue delphinidin pigment or do not have an intracellular environment suitable for developing blue color. Recently, it has become possible to incorporate a blue flower color trait through progress in molecular biological analysis of pigment biosynthesis genes and genetic engineering. For example, introduction of the F3 ' 5 ' H gene encoding flavonoid 3',5'-hydroxylase can produce delphinidin in various flowers such as roses and carnations, turning the flower color purple or violet. Furthermore, the world's first blue chrysanthemum was recently produced by introducing the A3 ' 5 ' GT gene encoding anthocyanin 3',5'- O -glucosyltransferase, in addition to F3 ' 5 ' H , into the host plant. The B-ring glucosylated delphinidin-based anthocyanin that is synthesized by the two transgenes develops blue coloration by co-pigmentation with colorless flavone glycosides naturally present in the ray floret of chrysanthemum. This review focuses on the biotechnological efforts to develop blue flowers, and describes future prospects for blue flower breeding and commercialization.

The Quest for Molecular Regulation Underlying Unisexual Flower Development

PubMed Central

Sobral, Rómulo; Silva, Helena G.; Morais-Cecílio, Leonor; Costa, Maria M. R.

2016-01-01

The understanding of the molecular mechanisms responsible for the making of a unisexual flower has been a long-standing quest in plant biology. Plants with male and female flowers can be divided mainly into two categories: dioecious and monoecious, and both sexual systems co-exist in nature in ca of 10% of the angiosperms. The establishment of male and female traits has been extensively described in a hermaphroditic flower and requires the interplay of networks, directly and indirectly related to the floral organ identity genes including hormonal regulators, transcription factors, microRNAs, and chromatin-modifying proteins. Recent transcriptomic studies have been uncovering the molecular processes underlying the establishment of unisexual flowers and there are many parallelisms between monoecious, dioecious, and hermaphroditic individuals. Here, we review the paper entitled “Comparative transcriptomic analysis of male and female flowers of monoecious Quercus suber” published in 2014 in the Frontiers of Plant Science (volume 5 |Article 599) and discussed it in the context of recent studies with other dioecious and monoecious plants that utilized high-throughput platforms to obtain transcriptomic profiles of male and female unisexual flowers. In some unisexual flowers, the developmental programs that control organ initiation fail and male or female organs do not form, whereas in other species, organ initiation and development occur but they abort or arrest during different species-specific stages of differentiation. Therefore, a direct comparison of the pathways responsible for the establishment of unisexual flowers in different species are likely to reveal conserved modules of gene regulatory hubs involved in stamen or carpel development, as well as differences that reflect the different stages of development in which male and/or female organ arrest or loss-of-function occurs. PMID:26925078

Recent advances in the research and development of blue flowers

PubMed Central

Noda, Naonobu

2018-01-01

Flower color is the most important trait in the breeding of ornamental plants. In the floriculture industry, however, bluish colored flowers of desirable plants have proved difficult to breed. Many ornamental plants with a high production volume, such as rose and chrysanthemum, lack the key genes for producing the blue delphinidin pigment or do not have an intracellular environment suitable for developing blue color. Recently, it has become possible to incorporate a blue flower color trait through progress in molecular biological analysis of pigment biosynthesis genes and genetic engineering. For example, introduction of the F3′5′H gene encoding flavonoid 3′,5′-hydroxylase can produce delphinidin in various flowers such as roses and carnations, turning the flower color purple or violet. Furthermore, the world’s first blue chrysanthemum was recently produced by introducing the A3′5′GT gene encoding anthocyanin 3′,5′-O-glucosyltransferase, in addition to F3′5′H, into the host plant. The B-ring glucosylated delphinidin-based anthocyanin that is synthesized by the two transgenes develops blue coloration by co-pigmentation with colorless flavone glycosides naturally present in the ray floret of chrysanthemum. This review focuses on the biotechnological efforts to develop blue flowers, and describes future prospects for blue flower breeding and commercialization. PMID:29681750

Transcriptional Analysis of Flowering Time in Switchgrass

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tornqvist, Carl-Erik; Vaillancourt, Brieanne; Kim, Jeongwoon

Over the past two decades, switchgrass (Panicum virgatum) has emerged as a priority biofuel feedstock. The bulk of switchgrass biomass is in the vegetative portion of the plant; therefore, increasing the length of vegetative growth will lead to an increase in overall biomass yield. The goal of this study was to gain insight into the control of flowering time in switchgrass that would assist in development of cultivars with longer vegetative phases through delayed flowering. RNA sequencing was used to assess genome-wide expression profiles across a developmental series between switchgrass genotypes belonging to the two main ecotypes: upland, typically earlymore » flowering, and lowland, typically late flowering. Leaf blades and tissues enriched for the shoot apical meristem (SAM) were collected in a developmental series from emergence through anthesis for RNA extraction. RNA from samples that flanked the SAM transition stage was sequenced for expression analyses. The analyses revealed differential expression patterns between early- and late-flowering genotypes for known flowering time orthologs. Namely, genes shown to play roles in photoperiod response and the circadian clock in other species were identified as potential candidates for regulating flowering time in the switchgrass genotypes analyzed. Based on their expression patterns, many of the differentially expressed genes could also be classified as putative promoters or repressors of flowering. The candidate genes presented here may be used to guide switchgrass improvement through marker-assisted breeding and/or transgenic or gene editing approaches.Over the past two decades, switchgrass (Panicum virgatum) has emerged as a priority biofuel feedstock. The bulk of switchgrass biomass is in the vegetative portion of the plant; therefore, increasing the length of vegetative growth will lead to an increase in overall biomass yield. The goal of this study was to gain insight into the control of flowering time in

Transcriptional Analysis of Flowering Time in Switchgrass

DOE PAGES

Tornqvist, Carl-Erik; Vaillancourt, Brieanne; Kim, Jeongwoon; ...

2017-04-27

Over the past two decades, switchgrass (Panicum virgatum) has emerged as a priority biofuel feedstock. The bulk of switchgrass biomass is in the vegetative portion of the plant; therefore, increasing the length of vegetative growth will lead to an increase in overall biomass yield. The goal of this study was to gain insight into the control of flowering time in switchgrass that would assist in development of cultivars with longer vegetative phases through delayed flowering. RNA sequencing was used to assess genome-wide expression profiles across a developmental series between switchgrass genotypes belonging to the two main ecotypes: upland, typically earlymore » flowering, and lowland, typically late flowering. Leaf blades and tissues enriched for the shoot apical meristem (SAM) were collected in a developmental series from emergence through anthesis for RNA extraction. RNA from samples that flanked the SAM transition stage was sequenced for expression analyses. The analyses revealed differential expression patterns between early- and late-flowering genotypes for known flowering time orthologs. Namely, genes shown to play roles in photoperiod response and the circadian clock in other species were identified as potential candidates for regulating flowering time in the switchgrass genotypes analyzed. Based on their expression patterns, many of the differentially expressed genes could also be classified as putative promoters or repressors of flowering. The candidate genes presented here may be used to guide switchgrass improvement through marker-assisted breeding and/or transgenic or gene editing approaches.Over the past two decades, switchgrass (Panicum virgatum) has emerged as a priority biofuel feedstock. The bulk of switchgrass biomass is in the vegetative portion of the plant; therefore, increasing the length of vegetative growth will lead to an increase in overall biomass yield. The goal of this study was to gain insight into the control of flowering time in

Overexpression of two PsnAP1 genes from Populus simonii × P. nigra causes early flowering in transgenic tobacco and Arabidopsis.

PubMed

Zheng, Tangchun; Li, Shuang; Zang, Lina; Dai, Lijuan; Yang, Chuanping; Qu, Guan-Zheng

2014-01-01

In Arabidopsis, AP1 is a floral meristem identity gene and plays an important role in floral organ development. In this study, PsnAP1-1 and PsnAP1-2 were isolated from the male reproductive buds of poplar (Populus simonii × P. nigra), which are the orthologs of AP1 in Arabidopsis, by sequence analysis. Northern blot and qRT-PCR analysis showed that PsnAP1-1 and PsnAP1-2 exhibited high expression level in early inflorescence development of poplar. Subcellular localization showed the PsnAP1-1 and PsnAP1-2 proteins are localized in the nucleus. Overexpression of PsnAP1-1 and PsnAP1-2 in tobacco under the control of a CaMV 35S promoter significantly enhanced early flowering. These transgenic plants also showed much earlier stem initiation and higher rates of photosynthesis than did wild-type tobacco. qRT-PCR analysis further indicated that overexpression of PsnAP1-1 and PsnAP1-2 resulted in up-regulation of genes related to flowering, such as NtMADS4, NtMADS5 and NtMADS11. Overexpression of PsnAP1-1 and PsnAP1-2 in Arabidopsis also induced early flowering, but did not complement the ap1-10 floral morphology to any noticeable extent. This study indicates that PsnAP1-1 and PsnAP1-2 play a role in floral transition of poplar.

Overexpression of Two PsnAP1 Genes from Populus simonii × P. nigra Causes Early Flowering in Transgenic Tobacco and Arabidopsis

PubMed Central

Zheng, Tangchun; Li, Shuang; Zang, Lina; Dai, Lijuan; Yang, Chuanping; Qu, Guan-Zheng

2014-01-01

In Arabidopsis, AP1 is a floral meristem identity gene and plays an important role in floral organ development. In this study, PsnAP1-1 and PsnAP1-2 were isolated from the male reproductive buds of poplar (Populus simonii × P. nigra), which are the orthologs of AP1 in Arabidopsis, by sequence analysis. Northern blot and qRT-PCR analysis showed that PsnAP1-1 and PsnAP1-2 exhibited high expression level in early inflorescence development of poplar. Subcellular localization showed the PsnAP1-1 and PsnAP1-2 proteins are localized in the nucleus. Overexpression of PsnAP1-1 and PsnAP1-2 in tobacco under the control of a CaMV 35S promoter significantly enhanced early flowering. These transgenic plants also showed much earlier stem initiation and higher rates of photosynthesis than did wild-type tobacco. qRT-PCR analysis further indicated that overexpression of PsnAP1-1 and PsnAP1-2 resulted in up-regulation of genes related to flowering, such as NtMADS4, NtMADS5 and NtMADS11. Overexpression of PsnAP1-1 and PsnAP1-2 in Arabidopsis also induced early flowering, but did not complement the ap1-10 floral morphology to any noticeable extent. This study indicates that PsnAP1-1 and PsnAP1-2 play a role in floral transition of poplar. PMID:25360739

Variations in Hormones and Antioxidant Status in Relation to Flowering in Early, Mid, and Late Varieties of Date Palm (Phoenix dactylifera) of United Arab Emirates.

PubMed

Cheruth, Abdul J; Kurup, Shyam S; Subramaniam, Sreeramanan

2015-01-01

The present study was carried out to assess the status of various hormones responsible for the flower induction of Nagal, Lulu, and Khalas date palm varieties in UAE. The nonenzymatic antioxidant compounds and the antioxidant enzymatic activities at preflowering, flowering, and postflowering stages of the date palm varieties were quantified. The ABA and zeatin concentrations were found to be significantly higher during the preflowering stage but gradually decreased during the flowering period and then increased after the flowering stage. Gibberellic acid (GA) concentrations were significantly higher in the early flowering varieties and higher levels of ABA may contribute to the delayed flowering in mid and late varieties. The results on hormone profiling displayed a significant variation between seasons (preflowering, flowering, and postflowering) and also between the three date palms (early, mid, and late flowering varieties). Ascorbic acid (AA) concentration was low at the preflowering stage in the early flowering Nagal (0.694 mg/g dw), which is similar with the late flowering Lulu variety (0.862 mg/g dw). However, Khalas variety showed significantly higher amount of AA content (7.494 mg/g dw) at the preflowering stage when compared to other varieties. In flowering stage, Nagal (0.814 mg/g dw) and Lulu (0.963 mg/g dw) were similar with respect to the production of AA, while the mid flowering variety showed significantly higher amount of AA (9.358 mg/g dw). The Khalas variety produced the highest tocopherol at 4.78 mg/g dw compared to Nagal and Lulu, at 1.997 and 1.908 mg/g dw, respectively, during the preflowering stage. In Nagal variety, the content of reduced glutathione (GSH) at the preflowering stage was 0.507 mg/g dw, which was not significantly different from the flowering and postflowering stages at 0.4 and 0.45 mg/g dw, respectively. The GSH was significantly higher in Khalas compared to Nagal and Lulu varieties, at 1.321 mg/g w in the preflowering phase

Urbanisation induces early flowering: evidence from Platanus acerifolia and Prunus cerasus

NASA Astrophysics Data System (ADS)

Mimet, A.; Pellissier, V.; Quénol, H.; Aguejdad, R.; Dubreuil, V.; Rozé, F.

2009-05-01

The effect of towns on plant phenology, i.e. advancement of spring development compared with a rural environment, via the urban heat island (UHI) phenomenon, has been shown for many towns in many countries. This work combines experimental and observational methodology to provide a better and deeper view of climatic habitat in an urban context with a view to understanding the relationship between plant development and urban climate on the intra-urban scale (by taking into account town structure). A dense network of 17 meteorological stations was set up in Rennes, France, enabling us to identify and quantify climatic changes associated with the UHI. Meanwhile, phenological observations were made during early spring (March and April) in 2005 on Platanus acerifolia and Prunus cerasus to study the relationship between climatic and phenological data. The results show that there is both a climatic gradient and a developmental gradient corresponding to the type of urbanisation in the town of Rennes. The town influences plant phenology by reducing the diurnal temperature range and by increasing the minimum temperature as one approaches the town centre. The influence of ground cover type (plants or buildings) on development is also shown. The developmental phases of preflowering and flowering are influenced to differing extents by climatic variables. The period during which climatic variables are effective before a given developmental phase varies considerably. The preflowering phases are best correlated with the mean of the minimum air temperature for the 15-day period before the observation, whereas flowering appears to be more dependent on the mean of the daily diurnal temperature range for the 8 days preceding the observation.

Urbanisation induces early flowering: evidence from Platanus acerifolia and Prunus cerasus.

PubMed

Mimet, A; Pellissier, V; Quénol, H; Aguejdad, R; Dubreuil, V; Rozé, F

2009-05-01

The effect of towns on plant phenology, i.e. advancement of spring development compared with a rural environment, via the urban heat island (UHI) phenomenon, has been shown for many towns in many countries. This work combines experimental and observational methodology to provide a better and deeper view of climatic habitat in an urban context with a view to understanding the relationship between plant development and urban climate on the intra-urban scale (by taking into account town structure). A dense network of 17 meteorological stations was set up in Rennes, France, enabling us to identify and quantify climatic changes associated with the UHI. Meanwhile, phenological observations were made during early spring (March and April) in 2005 on Platanus acerifolia and Prunus cerasus to study the relationship between climatic and phenological data. The results show that there is both a climatic gradient and a developmental gradient corresponding to the type of urbanisation in the town of Rennes. The town influences plant phenology by reducing the diurnal temperature range and by increasing the minimum temperature as one approaches the town centre. The influence of ground cover type (plants or buildings) on development is also shown. The developmental phases of preflowering and flowering are influenced to differing extents by climatic variables. The period during which climatic variables are effective before a given developmental phase varies considerably. The preflowering phases are best correlated with the mean of the minimum air temperature for the 15-day period before the observation, whereas flowering appears to be more dependent on the mean of the daily diurnal temperature range for the 8 days preceding the observation.

Earlier flowering did not alter pollen limitation in an early flowering shrub under short-term experimental warming.

PubMed

Pan, Cheng-Chen; Feng, Qi; Zhao, Ha-Lin; Liu, Lin-De; Li, Yu-Lin; Li, Yu-Qiang; Zhang, Tong-Hui; Yu, Xiao-Ya

2017-06-05

In animal pollinated plants, phenological shifts caused by climate change may have important ecological consequences. However, no empirical evidence exists at present on the consequences that flowering phenology shifts have on the strength of pollen limitation under experimental warming. Here, we investigated the effects of experimental warming on flowering phenology, flower density, reproductive success, and pollen limitation intensity in Caragana microphylla and evaluated whether earlier flowering phenology affected plant reproduction and the level of pollen limitation using warmed and unwarmed open top chambers in the Horqin Sandy Land of Inner Mongolia, northern China. The results of this study indicated that artificial warming markedly advanced flower phenology rather than extending the duration of the flowering. Additionally, warming was found to significantly reduce flower density which led to seed production reduction, since there were insignificant effects observed on fruit set and seed number per fruit. Experimental floral manipulations showed that warming did not affect pollen limitation. These results revealed the negative effects of advanced phenology induced by warming on flower density and reproductive output, as well as the neutral effects on reproductive success and pollen limitation intensity of long surviving plants.

De novo sequencing and comparative transcriptome analysis of the male and hermaphroditic flowers provide insights into the regulation of flower formation in andromonoecious taihangia rupestris.

PubMed

Li, Weiguo; Zhang, Lihui; Ding, Zhan; Wang, Guodong; Zhang, Yandi; Gong, Hongmei; Chang, Tianjun; Zhang, Yanwen

2017-02-28

Taihangia rupestris, an andromonoecious plant species, bears both male and hermaphroditic flowers within the same individual. However, the establishment and development of male and hermaphroditic flowers in andromonoecious Taihangia remain poorly understood, due to the limited genetic and sequence information. To investigate the potential molecular mechanism in the regulation of Taihangia flower formation, we used de novo RNA sequencing to compare the transcriptome profiles of male and hermaphroditic flowers at early and late developmental stages. Four cDNA libraries, including male floral bud, hermaphroditic floral bud, male flower, and hermaphroditic flower, were constructed and sequenced by using the Illumina RNA-Seq method. Totally, 84,596,426 qualified Illumina reads were obtained and then assembled into 59,064 unigenes, of which 24,753 unigenes were annotated in the NCBI non-redundant protein database. In addition, 12,214, 7,153, and 8,115 unigenes were assigned into 53 Gene Ontology (GO) functional groups, 25 Clusters of Orthologous Group (COG) categories, and 126 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, respectively. By pairwise comparison of unigene abundance between the samples, we identified 1,668 differential expressed genes (DEGs), including 176 transcription factors (TFs) between the male and hermaphroditic flowers. At the early developmental stage, we found 263 up-regulated genes and 436 down-regulated genes expressed in hermaphroditic floral buds, while 844 up-regulated genes and 314 down-regulated genes were detected in hermaphroditic flowers at the late developmental stage. GO and KEGG enrichment analyses showed that a large number of DEGs were associated with a wide range of functions, including cell cycle, epigenetic processes, flower development, and biosynthesis of unsaturated fatty acid pathway. Finally, real-time quantitative PCR was conducted to validate the DEGs identified in the present study. In this study, transcriptome

Shielding Flowers Developing under Stress: Translating Theory to Field Application

PubMed Central

Chayut, Noam; Sobol, Shiri; Nave, Nahum; Samach, Alon

2014-01-01

Developing reproductive organs within a flower are sensitive to environmental stress. A higher incidence of environmental stress during this stage of a crop plants’ developmental cycle will lead to major breaches in food security. Clearly, we need to understand this sensitivity and try and overcome it, by agricultural practices and/or the breeding of more tolerant cultivars. Although passion fruit vines initiate flowers all year round, flower primordia abort during warm summers. This restricts the season of fruit production in regions with warm summers. Previously, using controlled chambers, stages in flower development that are sensitive to heat were identified. Based on genetic analysis and physiological experiments in controlled environments, gibberellin activity appeared to be a possible point of horticultural intervention. Here, we aimed to shield flowers of a commercial cultivar from end of summer conditions, thus allowing fruit production in new seasons. We conducted experiments over three years in different settings, and our findings consistently show that a single application of an inhibitor of gibberellin biosynthesis to vines in mid-August can cause precocious flowering of ~2–4 weeks, leading to earlier fruit production of ~1 month. In this case, knowledge obtained on phenology, environmental constraints and genetic variation, allowed us to reach a practical solution. PMID:27135506

Stamen-derived bioactive gibberellin is essential for male flower development of Cucurbita maxima L.

PubMed Central

Pimenta Lange, Maria João; Knop, Nicole; Lange, Theo

2012-01-01

Gibberellin (GA) signalling during pumpkin male flower development is highly regulated, including biosynthetic, perception, and transduction pathways. GA 20-oxidases, 3-oxidases, and 2-oxidases catalyse the final part of GA synthesis. Additionally, 7-oxidase initiates this part of the pathway in some cucurbits including Cucurbita maxima L. (pumpkin). Expression patterns for these GA-oxidase-encoding genes were examined by competitive reverse transcription-PCR (RT-PCR) and endogenous GA levels were determined during pumpkin male flower development. In young flowers, GA20ox3 transcript levels are high in stamens, followed by high levels of the GA precursor GA9. Later, just before flower opening, transcript levels for GA3ox3 and GA3ox4 increase in the hypanthium and stamens, respectively. In the stamen, following GA3ox4 expression, bioactive GA4 levels rise dramatically. Accordingly, catabolic GA2ox2 and GA2ox3 transcript levels are low in developing flowers, and increase in mature flowers. Putative GA receptor GID1b and DELLA repressor GAIPb transcript levels do not change in developing flowers, but increase sharply in mature flowers. Emasculation arrests floral development completely and leads to abscission of premature flowers. Application of GA4 (but not of its precursors GA12-aldehyde or GA9) restores normal growth of emasculated flowers. These results indicate that de novo GA4 synthesis in the stamen is under control of GA20ox3 and GA3ox4 genes just before the rapid flower growth phase. Stamen-derived bioactive GA is essential and sufficient for male flower development, including the petal and the pedicel growth. PMID:22268154

Overexpression of AtAP1M3 regulates flowering time and floral development in Arabidopsis and effects key flowering-related genes in poplar.

PubMed

Chen, Zhong; Ye, Meixia; Su, Xiaoxing; Liao, Weihua; Ma, Huandi; Gao, Kai; Lei, Bingqi; An, Xinmin

2015-08-01

APETALA1 plays a crucial role in the transition from vegetative to reproductive phase and in floral development. In this study, to determine the effect of AP1 expression on flowering time and floral organ development, transgenic Arabidopsis and poplar overexpressing of AtAP1M3 (Arabidopsis AP1 mutant by dominant negative mutation) were generated. Transgenic Arabidopsis with e35Spro::AtAP1M3 displayed phenotypes with delayed-flowering compared to wild-type and flowers with abnormal sepals, petals and stamens. In addition, transgenic Arabidopsis plants exhibited reduced growth vigor compared to the wild-type plants. Ectopic expression of AtAP1M3 in poplar resulted in up- or down-regulation of some endogenous key flowering-related genes, including floral meristems identity gene LFY, B-class floral organ identity genes AP3 and PI, flowering pathway integrator FT1 and flower repressors TFL1 and SVP. These results suggest that AtAP1M3 regulates flowering time and floral development in plants.

Proteomic Identification of Differentially Expressed Proteins during Alfalfa (Medicago sativa L.) Flower Development.

PubMed

Chen, Lingling; Chen, Quanzhu; Zhu, Yanqiao; Hou, Longyu; Mao, Peisheng

2016-01-01

Flower development, pollination, and fertilization are important stages in the sexual reproduction process of plants; they are also critical steps in the control of seed formation and development. During alfalfa ( Medicago sativa L.) seed production, some distinct phenomena such as a low seed setting ratio, serious flower falling, and seed abortion commonly occur. However, the causes of these phenomena are complicated and largely unknown. An understanding of the mechanisms that regulate alfalfa flowering is important in order to increase seed yield. Hence, proteomic technology was used to analyze changes in protein expression during the stages of alfalfa flower development. Flower samples were collected at pre-pollination (S1), pollination (S2), and the post-pollination senescence period (S3). Twenty-four differentially expressed proteins were successfully identified, including 17 down-regulated in pollinated flowers, one up-regulated in pollinated and senesced flowers, and six up-regulated in senesced flowers. The largest proportions of the identified proteins were involved in metabolism, signal transduction, defense response, oxidation reduction, cell death, and programmed cell death (PCD). Their expression profiles demonstrated that energy metabolism, carbohydrate metabolism, and amino acid metabolism provided the nutrient foundation for pollination in alfalfa. Furthermore, there were three proteins involved in multiple metabolic pathways: dual specificity kinase splA-like protein (kinase splALs), carbonic anhydrase, and NADPH: quinone oxidoreductase-like protein. Expression patterns of these proteins indicated that MAPK cascades regulated multiple processes, such as signal transduction, stress response, and cell death. PCD also played an important role in the alfalfa flower developmental process, and regulated both pollination and flower senescence. The current study sheds some light on protein expression profiles during alfalfa flower development and

Proteomic Identification of Differentially Expressed Proteins during Alfalfa (Medicago sativa L.) Flower Development

PubMed Central

Chen, Lingling; Chen, Quanzhu; Zhu, Yanqiao; Hou, Longyu; Mao, Peisheng

2016-01-01

Flower development, pollination, and fertilization are important stages in the sexual reproduction process of plants; they are also critical steps in the control of seed formation and development. During alfalfa (Medicago sativa L.) seed production, some distinct phenomena such as a low seed setting ratio, serious flower falling, and seed abortion commonly occur. However, the causes of these phenomena are complicated and largely unknown. An understanding of the mechanisms that regulate alfalfa flowering is important in order to increase seed yield. Hence, proteomic technology was used to analyze changes in protein expression during the stages of alfalfa flower development. Flower samples were collected at pre-pollination (S1), pollination (S2), and the post-pollination senescence period (S3). Twenty-four differentially expressed proteins were successfully identified, including 17 down-regulated in pollinated flowers, one up-regulated in pollinated and senesced flowers, and six up-regulated in senesced flowers. The largest proportions of the identified proteins were involved in metabolism, signal transduction, defense response, oxidation reduction, cell death, and programmed cell death (PCD). Their expression profiles demonstrated that energy metabolism, carbohydrate metabolism, and amino acid metabolism provided the nutrient foundation for pollination in alfalfa. Furthermore, there were three proteins involved in multiple metabolic pathways: dual specificity kinase splA-like protein (kinase splALs), carbonic anhydrase, and NADPH: quinone oxidoreductase-like protein. Expression patterns of these proteins indicated that MAPK cascades regulated multiple processes, such as signal transduction, stress response, and cell death. PCD also played an important role in the alfalfa flower developmental process, and regulated both pollination and flower senescence. The current study sheds some light on protein expression profiles during alfalfa flower development and

Variation in the flowering gene SELF PRUNING 5G promotes day-neutrality and early yield in tomato.

PubMed

Soyk, Sebastian; Müller, Niels A; Park, Soon Ju; Schmalenbach, Inga; Jiang, Ke; Hayama, Ryosuke; Zhang, Lei; Van Eck, Joyce; Jiménez-Gómez, José M; Lippman, Zachary B

2017-01-01

Plants evolved so that their flowering is triggered by seasonal changes in day length. However, day-length sensitivity in crops limits their geographical range of cultivation, and thus modification of the photoperiod response was critical for their domestication. Here we show that loss of day-length-sensitive flowering in tomato was driven by the florigen paralog and flowering repressor SELF-PRUNING 5G (SP5G). SP5G expression is induced to high levels during long days in wild species, but not in cultivated tomato because of cis-regulatory variation. CRISPR/Cas9-engineered mutations in SP5G cause rapid flowering and enhance the compact determinate growth habit of field tomatoes, resulting in a quick burst of flower production that translates to an early yield. Our findings suggest that pre-existing variation in SP5G facilitated the expansion of cultivated tomato beyond its origin near the equator in South America, and they provide a compelling demonstration of the power of gene editing to rapidly improve yield traits in crop breeding.

Roles of jasmonate signalling in plant inflorescence and flower development.

PubMed

Yuan, Zheng; Zhang, Dabing

2015-10-01

Development of inflorescences and flowers in plants is controlled by the combined action of environmental and genetic signals. Investigations reveal that the phytohormone jasmonate (JA) plays a critical function in plant reproduction such as male fertility, sex determination and seed maturation. Here, we review recent progress on JA synthesis, signalling, the interplay between JAs and other hormones, and regulatory network of JA in controlling the development of inflorescence, flower and the male organ. The conserved and diversified roles of JAs in meristem transition and specification of flower organ identity and number, and multiple regulatory networks of JAs in stamen development are highlighted. Further, this review provides perspectives on future research endeavors to elucidate mechanisms underlying JAs homeostasis and transport during plant reproductive development. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Vaccinium corymbosum FLOWERING LOCUS T-like gene (VcFT): a flowering activator reverses photoperiodic and chilling requirements in blueberry.

PubMed

Song, Guo-qing; Walworth, Aaron; Zhao, Dongyan; Jiang, Ning; Hancock, James F

2013-11-01

The blueberry FLOWERING LOCUS T ( FT )-like gene ( VcFT ) cloned from the cDNA of a tetraploid, northern highbush blueberry ( Vaccinium corymbosum L.) is able to reverse the photoperiodic and chilling requirements and drive early and continuous flowering. Blueberry is a woody perennial bush with a longer juvenile period than annual crops, requiring vernalization to flower normally. Few studies have been reported on the molecular mechanism of flowering in blueberry or other woody plants. Because FLOWERING LOCUS T (FT) from Arabidopsis thaliana plays a multifaceted role in generating mobile molecular signals to regulate plant flowering time, isolation and functional analysis of the blueberry (Vaccinium corymbosum L.) FT-like gene (VcFT) will facilitate the elucidation of molecular mechanisms of flowering in woody plants. Based on EST sequences, a 525-bpVcFT was identified and cloned from the cDNA of a tetraploid, northern highbush blueberry cultivar, Bluecrop. Ectopic expression of 35S:VcFT in tobacco induced flowering an average of 28 days earlier than wild-type plants. Expression of the 35S:VcFT in the blueberry cultivar Aurora resulted in an extremely early flowering phenotype, which flowered not only during in vitro culture, a growth stage when nontransgenic shoots had not yet flowered, but also in 6-10-week old, soil-grown transgenic plants, in contrast to the fact that at least 1 year and 800 chilling hours are required for the appearance of the first flower of both nontransgenic 'Aurora' and transgenic controls with the gusA. These results demonstrate that the VcFT is a functional floral activator and overexpression of the VcFT is able to reverse the photoperiodic and chilling requirements and drive early and continuous flowering.

Transcriptomic analysis of flower development in tea (Camellia sinensis (L.)).

PubMed

Liu, Feng; Wang, Yu; Ding, Zhaotang; Zhao, Lei; Xiao, Jun; Wang, Linjun; Ding, Shibo

2017-10-05

Flowering is a critical and complicated process in plant development, involving interactions of numerous endogenous and environmental factors, but little is known about the complex network regulating flower development in tea plants. In this study, de novo transcriptome assembly and gene expression analysis using Illumina sequencing technology were performed. Transcriptomic analysis assembles gene-related information involved in reproductive growth of C. sinensis. Gene Ontology (GO) analysis of the annotated unigenes revealed that the majority of sequenced genes were associated with metabolic and cellular processes, cell and cell parts, catalytic activity and binding. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated that metabolic pathways, biosynthesis of secondary metabolites, and plant hormone signal transduction were enriched among the DEGs. Furthermore, 207 flowering-associated unigenes were identified from our database. Some transcription factors, such as WRKY, ERF, bHLH, MYB and MADS-box were shown to be up-regulated in floral transition, which might play the role of progression of flowering. Furthermore, 14 genes were selected for confirmation of expression levels using quantitative real-time PCR (qRT-PCR). The comprehensive transcriptomic analysis presents fundamental information on the genes and pathways which are involved in flower development in C. sinensis. Our data also provided a useful database for further research of tea and other species of plants. Copyright © 2017 Elsevier B.V. All rights reserved.

Epigenetic processes in flowering plant reproduction.

PubMed

Wang, Guifeng; Köhler, Claudia

2017-02-01

Seeds provide up to 70% of the energy intake of the human population, emphasizing the relevance of understanding the genetic and epigenetic mechanisms controlling seed formation. In flowering plants, seeds are the product of a double fertilization event, leading to the formation of the embryo and the endosperm surrounded by maternal tissues. Analogous to mammals, plants undergo extensive epigenetic reprogramming during both gamete formation and early seed development, a process that is supposed to be required to enforce silencing of transposable elements and thus to maintain genome stability. Global changes of DNA methylation, histone modifications, and small RNAs are closely associated with epigenome programming during plant reproduction. Here, we review current knowledge on chromatin changes occurring during sporogenesis and gametogenesis, as well as early seed development in major flowering plant models. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Identification of microRNAs differentially expressed involved in male flower development.

PubMed

Wang, Zhengjia; Huang, Jianqin; Sun, Zhichao; Zheng, Bingsong

2015-03-01

Hickory (Carya cathayensis Sarg.) is one of the most economically important woody trees in eastern China, but its long flowering phase delays yield. Our understanding of the regulatory roles of microRNAs (miRNAs) in male flower development in hickory remains poor. Using high-throughput sequencing technology, we have pyrosequenced two small RNA libraries from two male flower differentiation stages in hickory. Analysis of the sequencing data identified 114 conserved miRNAs that belonged to 23 miRNA families, five novel miRNAs including their corresponding miRNA*s, and 22 plausible miRNA candidates. Differential expression analysis revealed 12 miRNA sequences that were upregulated in the later (reproductive) stage of male flower development. Quantitative real-time PCR showed similar expression trends as that of the deep sequencing. Novel miRNAs and plausible miRNA candidates were predicted using bioinformatic analysis methods. The miRNAs newly identified in this study have increased the number of known miRNAs in hickory, and the identification of differentially expressed miRNAs will provide new avenues for studies into miRNAs involved in the process of male flower development in hickory and other related trees.

FlowerMorphology: fully automatic flower morphometry software.

PubMed

Rozov, Sergey M; Deineko, Elena V; Deyneko, Igor V

2018-05-01

The software FlowerMorphology is designed for automatic morphometry of actinomorphic flowers. The novel complex parameters of flowers calculated by FlowerMorphology allowed us to quantitatively characterize a polyploid series of tobacco. Morphological differences of plants representing closely related lineages or mutants are mostly quantitative. Very often, there are only very fine variations in plant morphology. Therefore, accurate and high-throughput methods are needed for their quantification. In addition, new characteristics are necessary for reliable detection of subtle changes in morphology. FlowerMorphology is an all-in-one software package to automatically image and analyze five-petal actinomorphic flowers of the dicotyledonous plants. Sixteen directly measured parameters and ten calculated complex parameters of a flower allow us to characterize variations with high accuracy. The program was developed for the needs of automatic characterization of Nicotiana tabacum flowers, but is applicable to many other plants with five-petal actinomorphic flowers and can be adopted for flowers of other merosity. A genetically similar polyploid series of N. tabacum plants was used to investigate differences in flower morphology. For the first time, we could quantify the dependence between ploidy and size and form of the tobacco flowers. We found that the radius of inner petal incisions shows a persistent positive correlation with the chromosome number. In contrast, a commonly used parameter-radius of outer corolla-does not discriminate 2n and 4n plants. Other parameters show that polyploidy leads to significant aberrations in flower symmetry and are also positively correlated with chromosome number. Executables of FlowerMorphology, source code, documentation, and examples are available at the program website: https://github.com/Deyneko/FlowerMorphology .

Regulation of flower development in Arabidopsis by SCF complexes.

PubMed

Ni, Weimin; Xie, Daoxin; Hobbie, Lawrence; Feng, Baomin; Zhao, Dazhong; Akkara, Joseph; Ma, Hong

2004-04-01

SCF complexes are the largest and best studied family of E3 ubiquitin protein ligases that facilitate the ubiquitylation of proteins targeted for degradation. The SCF core components Skp1, Cul1, and Rbx1 serve in multiple SCF complexes involving different substrate-specific F-box proteins that are involved in diverse processes including cell cycle and development. In Arabidopsis, mutations in the F-box gene UNUSUAL FLORAL ORGANS (UFO) result in a number of defects in flower development. However, functions of the core components Cul1 and Rbx1 in flower development are poorly understood. In this study we analyzed floral phenotypes caused by altering function of Cul1 or Rbx1, as well as the effects of mutations in ASK1 and ASK2. Plants homozygous for a point mutation in the AtCUL1 gene showed reduced floral organ number and several defects in each of the four whorls. Similarly, plants with reduced AtRbx1 expression due to RNA interference also exhibited floral morphological defects. In addition, compared to the ask1 mutant, plants homozygous for ask1 and heterozygous for ask2 displayed enhanced reduction of B function, as well as other novel defects of flower development, including carpelloid sepals and an inhibition of petal development. Genetic analyses demonstrate that AGAMOUS (AG) is required for the novel phenotypes observed in the first and second whorls. Furthermore, the genetic interaction between UFO and AtCUL1 supports the idea that UFO regulates multiple aspects of flower development as a part of SCF complexes. These results suggest that SCF complexes regulate several aspects of floral development in Arabidopsis.

Central cell-derived peptides regulate early embryo patterning in flowering plants.

PubMed

Costa, Liliana M; Marshall, Eleanor; Tesfaye, Mesfin; Silverstein, Kevin A T; Mori, Masashi; Umetsu, Yoshitaka; Otterbach, Sophie L; Papareddy, Ranjith; Dickinson, Hugh G; Boutiller, Kim; VandenBosch, Kathryn A; Ohki, Shinya; Gutierrez-Marcos, José F

2014-04-11

Plant embryogenesis initiates with the establishment of an apical-basal axis; however, the molecular mechanisms accompanying this early event remain unclear. Here, we show that a small cysteine-rich peptide family is required for formation of the zygotic basal cell lineage and proembryo patterning in Arabidopsis. EMBRYO SURROUNDING FACTOR 1 (ESF1) peptides accumulate before fertilization in central cell gametes and thereafter in embryo-surrounding endosperm cells. Biochemical and structural analyses revealed cleavage of ESF1 propeptides to form biologically active mature peptides. Further, these peptides act in a non-cell-autonomous manner and synergistically with the receptor-like kinase SHORT SUSPENSOR to promote suspensor elongation through the YODA mitogen-activated protein kinase pathway. Our findings demonstrate that the second female gamete and its sexually derived endosperm regulate early embryonic patterning in flowering plants.

Flower development and sex specification in wild grapevine.

PubMed

Ramos, Miguel Jesus Nunes; Coito, João Lucas; Silva, Helena Gomes; Cunha, Jorge; Costa, Maria Manuela Ribeiro; Rocheta, Margarida

2014-12-12

Wild plants of Vitis closely related to the cultivated grapevine (V. v. vinifera) are believed to have been first domesticated 10,000 years BC around the Caspian Sea. V. v. vinifera is hermaphrodite whereas V. v. sylvestris is a dioecious species. Male flowers show a reduced pistil without style or stigma and female flowers present reflexed stamens with infertile pollen. V. vinifera produce perfect flowers with all functional structures. The mechanism for flower sex determination and specification in grapevine is still unknown. To understand which genes are involved during the establishment of male, female and complete flowers, we analysed and compared the transcription profiles of four developmental stages of the three genders. We showed that sex determination is a late event during flower development and that the expression of genes from the ABCDE model is not directly correlated with the establishment of sexual dimorphism. We propose a temporal comprehensive model in which two mutations in two linked genes could be players in sex determination and indirectly establish the Vitis domestication process. Additionally, we also found clusters of genes differentially expressed between genders and between developmental stages that suggest a role involved in sex differentiation. Also, the detection of differentially transcribed regions that extended existing gene models (intergenic regions) between sexes suggests that they may account for some of the variation between the subspecies. There is no evidence of differences of expression levels in genes from the ABCDE model that could explain the shift from hermaphroditism to dioecy. We propose that sex specification occurs after floral organ identity has been established and therefore, sex determination genes might be having an effect downstream of the ABCDE model genes.For the first time a full transcriptomic analysis was performed in different flower developmental stages in the same individual. Our experimental approach

Recent advances on the development and regulation of flower color in ornamental plants

PubMed Central

Zhao, Daqiu; Tao, Jun

2015-01-01

Flower color is one of the most important features of ornamental plants. Its development and regulation are influenced by many internal and external factors. Therefore, understanding the mechanism of color development and its regulation provides an important theoretical basis and premise for the cultivation and improvement of new color varieties of ornamental plants. This paper outlines the functions of petal tissue structure, as well as the distribution and type of pigments, especially anthocyanins, in color development. The progress of research on flower color regulation with a focus on physical factors, chemical factors, and genetic engineering is introduced. The shortcomings of flower color research and the potential directions for future development are explored to provide a broad background for flower color improvements in ornamental plants. PMID:25964787

Southern Monarchs do not Develop Learned Preferences for Flowers With Pyrrolizidine Alkaloids.

PubMed

de Oliveira, Marina Vasconcelos; Trigo, José Roberto; Rodrigues, Daniela

2015-07-01

Danaus butterflies sequester pyrrolizidine alkaloids (PAs) from nectar and leaves of various plant species for defense and reproduction. We tested the hypothesis that the southern monarch butterfly Danaus erippus shows innate preferences for certain flower colors and has the capacity to develop learned preferences for artificial flowers presenting advantageous floral rewards such as PAs. We predicted that orange and yellow flowers would be innately preferred by southern monarchs. Another prediction is that flowers with both sucrose and PAs would be preferred over those having sucrose only, regardless of flower color. In nature, males of Danaus generally visit PA sources more often than females, so we expected that males of D. erippus would exhibit a stronger learned preference for PA sources than the females. In the innate preference tests, adults were offered artificial non-rewarding yellow, orange, blue, red, green, and violet flowers. Orange and yellow artificial flowers were most visited by southern monarchs, followed by blue and red ones. No individual visited either green or violet flowers. For assessing learned preferences for PA flowers over flowers with no PAs, southern monarchs were trained to associate orange flowers with sucrose plus the PA monocrotaline vs. yellow flowers with sucrose only; the opposite combination was used to train another set of butterflies. In the tests, empty flowers were offered to trained butterflies. Neither males nor females showed learned preferences for flower colors associated with PAs in the training set. Thus, southern monarchs resemble the sister species Danaus plexippus in their innate preferences for orange and yellow flowers. Southern monarchs, similarly to temperate monarchs, might not be as PA-demanding as are other danaine species.

New development with cultural management related to flowering

USDA-ARS?s Scientific Manuscript database

Control of flowering is important in strawberry (Fragaria x ananassa Duch.) production. Plants have evolved mechanisms to alter their growth and development in response to environmental signals. The transition from vegetative to reproductive development in strawberries is regulated by a number of ...

Coordination of flower development by homeotic master regulators.

PubMed

Ito, Toshiro

2011-02-01

Floral homeotic genes encode transcription factors and act as master regulators of flower development. The homeotic protein complex is expressed in a specific whorl of the floral primordium and determines floral organ identity by the combinatorial action. Homeotic proteins continue to be expressed until late in flower development to coordinate growth and organogenesis. Recent genomic studies have shown that homeotic proteins bind thousands of target sites in the genome and regulate the expression of transcription factors, chromatin components and various proteins involved in hormone biosynthesis and signaling and other physiological activities. Further, homeotic proteins program chromatin to direct the developmental coordination of stem cell maintenance and differentiation in shaping floral organs. Copyright © 2010 Elsevier Ltd. All rights reserved.

Comparative transcriptomic analysis of the evolution and development of flower size in Saltugilia (Polemoniaceae).

PubMed

Landis, Jacob B; Soltis, Douglas E; Soltis, Pamela S

2017-06-23

Flower size varies dramatically across angiosperms, representing innovations over the course of >130 million years of evolution and contributing substantially to relationships with pollinators. However, the genetic underpinning of flower size is not well understood. Saltugilia (Polemoniaceae) provides an excellent non-model system for extending the genetic study of flower size to interspecific differences that coincide with variation in pollinators. Using targeted gene capture methods, we infer phylogenetic relationships among all members of Saltugilia to provide a framework for investigating the genetic control of flower size differences via RNA-Seq de novo assembly. Nuclear concatenation and species tree inference methods provide congruent topologies. The inferred evolutionary trajectory of flower size is from small flowers to larger flowers. We identified 4 to 10,368 transcripts that are differentially expressed during flower development, with many unigenes associated with cell wall modification and components of the auxin and gibberellin pathways. Saltugilia is an excellent model for investigating covarying floral and pollinator evolution. Four candidate genes from model systems (BIG BROTHER, BIG PETAL, GASA, and LONGIFOLIA) show differential expression during development of flowers in Saltugilia, and four other genes (FLOWERING-PROMOTING FACTOR 1, PECTINESTERASE, POLYGALACTURONASE, and SUCROSE SYNTHASE) fit into hypothesized organ size pathways. Together, these gene sets provide a strong foundation for future functional studies to determine their roles in specifying interspecific differences in flower size.

The Antioxidants Changes in Ornamental Flowers during Development and Senescence

PubMed Central

Cavaiuolo, Marina; Cocetta, Giacomo; Ferrante, Antonio

2013-01-01

The concentration of antioxidant compounds is constitutive and variable from species to species and is also variable considering the development of the plant tissue. In this review, we take into consideration the antioxidant changes and the physiological, biochemical and molecular factors that are able to modulate the accumulation of antioxidant compounds in ornamental flowers during the whole development process until the senescence. Many ornamental flowers are natural sources of very important bioactive compounds with benefit to the human health and their possible role as dietary components has been reported. The most part of antioxidants are flower pigments such as carotenoids and polyphenols, often present in higher concentration compared with the most common fruits and vegetables. The antioxidants content changes during development and during senescence many biochemical systems and molecular mechanisms are activated to counteract the increase of reactive oxygen species and free radicals. There is a tight correlation between antioxidants and senescence processes and this aspect is detailed and appropriately discussed. PMID:26784342

Ovary-derived precursor gibberellin A9 is essential for female flower development in cucumber.

PubMed

Pimenta Lange, Maria João; Lange, Theo

2016-12-01

Gibberellins (GAs) are hormones that control many aspects of plant development, including flowering. It is well known that stamen is the source of GAs that regulate male and bisexual flower development. However, little is known about the role of GAs in female flower development. In cucumber, high levels of GA precursors are present in ovaries and high levels of bioactive GA 4 are identified in sepals/petals, reflecting the expression of GA 20-oxidase and 3-oxidase in these organs, respectively. Here, we show that the biologically inactive precursor GA 9 moves from ovaries to sepal/petal tissues where it is converted to the bioactive GA 4 necessary for female flower development. Transient expression of a catabolic GA 2-oxidase from pumpkin in cucumber ovaries decreases GA 9 and GA 4 levels and arrests the development of female flowers, and this can be restored by application of GA 9 to petals thus confirming its function. Given that bioactive GAs can promote sex reversion of female flowers, movement of biologically inactive precursors, instead of the hormone itself, might help to maintain floral organ identity, ensuring fruit and seed production. © 2016. Published by The Company of Biologists Ltd.

Comparative transcriptome analyses of flower development in four species of Achimenes (Gesneriaceae).

PubMed

Roberts, Wade R; Roalson, Eric H

2017-03-20

Flowers have an amazingly diverse display of colors and shapes, and these characteristics often vary significantly among closely related species. The evolution of diverse floral form can be thought of as an adaptive response to pollination and reproduction, but it can also be seen through the lens of morphological and developmental constraints. To explore these interactions, we use RNA-seq across species and development to investigate gene expression and sequence evolution as they relate to the evolution of the diverse flowers in a group of Neotropical plants native to Mexico-magic flowers (Achimenes, Gesneriaceae). The assembled transcriptomes contain between 29,000 and 42,000 genes expressed during development. We combine sequence orthology and coexpression clustering with analyses of protein evolution to identify candidate genes for roles in floral form evolution. Over 25% of transcripts captured were distinctive to Achimenes and overrepresented by genes involved in transcription factor activity. Using a model-based clustering approach we find dynamic, temporal patterns of gene expression among species. Selection tests provide evidence of positive selection in several genes with roles in pigment production, flowering time, and morphology. Combining these approaches to explore genes related to flower color and flower shape, we find distinct patterns that correspond to transitions of floral form among Achimenes species. The floral transcriptomes developed from four species of Achimenes provide insight into the mechanisms involved in the evolution of diverse floral form among closely related species with different pollinators. We identified several candidate genes that will serve as an important and useful resource for future research. High conservation of sequence structure, patterns of gene coexpression, and detection of positive selection acting on few genes suggests that large phenotypic differences in floral form may be caused by genetic differences in a small

Genetic regulation of maize flower development and sex determination.

PubMed

Li, Qinglin; Liu, Baoshen

2017-01-01

The determining process of pistil fate are central to maize sex determination, mainly regulated by a genetic network in which the sex-determining genes SILKLESS 1 , TASSEL SEED 1 , TASSEL SEED 2 and the paramutagenic locus Required to maintain repression 6 play pivotal roles. Maize silks, which emerge from the ear shoot and derived from the pistil, are the functional stigmas of female flowers and play a pivotal role in pollination. Previous studies on sex-related mutants have revealed that sex-determining genes and phytohormones play an important role in the regulation of flower organogenesis. The processes determining pistil fate are central to flower development, where a silk identified gene SILKLESS 1 (SK1) is required to protect pistil primordia from a cell death signal produced by two commonly known genes, TASSEL SEED 1 (TS1) and TASSEL SEED 2 (TS2). In this review, maize flower developmental process is presented together with a focus on important sex-determining mutants and hormonal signaling affecting pistil development. The role of sex-determining genes, microRNAs, phytohormones, and the paramutagenic locus Required to maintain repression 6 (Rmr6), in forming a regulatory network that determines pistil fate, is discussed. Cloning SK1 and clarifying its function were crucial in understanding the regulation network of sex determination. The signaling mechanisms of phytohormones in sex determination are also an important research focus.

Fossil flowers from the early Palaeocene of Patagonia, Argentina, with affinity to Schizomerieae (Cunoniaceae)

PubMed Central

Jud, Nathan A; Gandolfo, Maria A; Iglesias, Ari; Wilf, Peter

2018-01-01

Abstract Background and Aims Early Palaeocene (Danian) plant fossils from Patagonia provide information on the recovery from the end-Cretaceous extinction and Cenozoic floristic change in South America. Actinomorphic flowers with eight to ten perianth parts are described and evaluated in a phylogenetic framework. The goal of this study is to determine the identity of these fossil flowers and to discuss their evolutionary, palaeoecological and biogeographical significance Methods More than 100 fossilized flowers were collected from three localities in the Danian Salamanca and Peñas Coloradas Formations in southern Chubut. They were prepared, photographed and compared with similar extant and fossil flowers using published literature and herbarium specimens. Phylogenetic analysis was performed using morphological and molecular data. Key results The fossil flowers share some but not all the synapomorphies that characterize the Schizomerieae, a tribe within Cunoniaceae. These features include the shallow floral cup, variable number of perianth parts arranged in two whorls, laciniate petals, anthers with a connective extension, and a superior ovary with free styles. The number of perianth parts is doubled and the in situ pollen is tricolporate, with a surface more like that of other Cunoniaceae outside Schizomerieae, such as Davidsonia or Weinmannia. Conclusions An extinct genus of crown-group Cunoniaceae is recognized and placed along the stem lineage leading to Schizomerieae. Extant relatives are typical of tropical to southern-temperate rainforests, and these fossils likely indicate a similarly warm and wet temperate palaeoclimate. The oldest reliable occurrences of the family are fossil pollen and wood from the Upper Cretaceous of the Antarctica and Argentina, whereas in Australia the family first occurs in upper Palaeocene deposits. This discovery demonstrates that the family survived the Cretaceous–Palaeogene boundary event in Patagonia and that diversification

Flowers regulate the growth and vascular development of the inflorescence rachis in Vitis vinifera L.

PubMed

Gourieroux, Aude M; McCully, Margaret E; Holzapfel, Bruno P; Scollary, Geoffrey R; Rogiers, Suzy Y

2016-11-01

The rachis, the structural framework of the grapevine (Vitis vinifera L.) inflorescence (and subsequent bunch), consists of a main axis and one or more orders of lateral branches with the flower-bearing pedicels at their fine tips. The rachis is crucial both for support, and transport from the shoot. Earlier suggestions that the flowers per se affect normal rachis development are investigated further in this study. Different percentages (0, 25, 50, 75 or 100) of flowers were removed manually one week before anthesis on field-grown vines. Treatment effects on subsequent rachis development (curvature, vitality, anatomy, starch deposit) were assessed. Sections, both fixed and embedded, and fresh hand-cut were observed by fluorescence and bright-field optics after appropriate staining. Emphasis was on measurement of changes in cross-sectional area of secondary xylem and phloem, and on maturation of fibres and periderm. Specific defects in rachis development were dependent on the percent and location of flower removal one week prior to anthesis. The rachises curved inwards where most of the flowers were removed. When fully de-flowered, they became progressively necrotic from the laterals back to the primary axes and from the distal to the proximal end of those axes, with a concurrent disorganisation of their anatomy. A few remaining groups of flowers prevented desiccation and abscission of the rachis axes proximal to the group, but not distally. Flower removal (50%) reduced rachis elongation, while 75% removal reduced xylem and phloem area and delayed phloem fibre and periderm development. 75% flower removal did not affect starch present in the rachis during berry development. Developing flowers affect the growth and vitality of the rachis and the development of its vascular and support structures. The extent of these effects depends on the cultivar and the number and position of flowers remaining after some are removed one week before anthesis. Copyright © 2016

Garlic (Allium sativum L.) fertility: transcriptome and proteome analyses provide insight into flower and pollen development

PubMed Central

Shemesh-Mayer, Einat; Ben-Michael, Tomer; Rotem, Neta; Rabinowitch, Haim D.; Doron-Faigenboim, Adi; Kosmala, Arkadiusz; Perlikowski, Dawid; Sherman, Amir; Kamenetsky, Rina

2015-01-01

Commercial cultivars of garlic, a popular condiment, are sterile, making genetic studies and breeding of this plant challenging. However, recent fertility restoration has enabled advanced physiological and genetic research and hybridization in this important crop. Morphophysiological studies, combined with transcriptome and proteome analyses and quantitative PCR validation, enabled the identification of genes and specific processes involved in gametogenesis in fertile and male-sterile garlic genotypes. Both genotypes exhibit normal meiosis at early stages of anther development, but in the male-sterile plants, tapetal hypertrophy after microspore release leads to pollen degeneration. Transcriptome analysis and global gene-expression profiling showed that >16,000 genes are differentially expressed in the fertile vs. male-sterile developing flowers. Proteome analysis and quantitative comparison of 2D-gel protein maps revealed 36 significantly different protein spots, 9 of which were present only in the male-sterile genotype. Bioinformatic and quantitative PCR validation of 10 candidate genes exhibited significant expression differences between male-sterile and fertile flowers. A comparison of morphophysiological and molecular traits of fertile and male-sterile garlic flowers suggests that respiratory restrictions and/or non-regulated programmed cell death of the tapetum can lead to energy deficiency and consequent pollen abortion. Potential molecular markers for male fertility and sterility in garlic are proposed. PMID:25972879

Genetic control of flowering and biomass in switchgrass

USDA-ARS?s Scientific Manuscript database

Early flowering can negatively affect biomass yield of switchgrass. In temperate regions of the USA, flowering occurs in switchgrass around the time of peak biomass yield (about 5 to 8 weeks prior to killing frost), effectively reducing the length of the growing season. The use of late-flowering swi...

Fast-Flowering Mini-Maize: Seed to Seed in 60 Days

PubMed Central

McCaw, Morgan E.; Wallace, Jason G.; Albert, Patrice S.; Buckler, Edward S.; Birchler, James A.

2016-01-01

Two lines of Zea mays were developed as a short-generation model for maize. The Fast-Flowering Mini-Maize (FFMM) lines A and B are robust inbred lines with a significantly shorter generation time, much smaller stature, and better greenhouse adaptation than traditional maize varieties. Five generations a year are typical. FFMM is the result of a modified double-cross hybrid between four fast-flowering lines: Neuffer’s Early ACR (full color), Alexander’s Early Early Synthetic, Tom Thumb Popcorn, and Gaspe Flint, followed by selection for early flowering and desirable morphology throughout an 11-generation selfing regime. Lines A and B were derived from different progeny of the initial hybrid, and crosses between Mini-Maize A and B exhibit heterosis. The ancestry of each genomic region of Mini-Maize A and B was inferred from the four founder populations using genotyping by sequencing. Other genetic and genomic tools for these lines include karyotypes for both lines A and B, kernel genetic markers y1 (white endosperm) and R1-scm2 (purple endosperm and embryo) introgressed into Mini-Maize A, and ∼24× whole-genome resequencing data for Mini-Maize A. PMID:27440866

Exon skipping of AGAMOUS homolog PrseAG in developing double flowers of Prunus lannesiana (Rosaceae).

PubMed

Liu, Zhixiong; Zhang, Dandan; Liu, Di; Li, Fenglan; Lu, Hai

2013-02-01

KEY MESSAGE : Two transcript isoforms of AGAMOUS homologs, from single and double flower Prunus lannesiana, respectively, showed different functions. The Arabidopsis floral homeotic C function gene AGAMOUS (AG) confers stamen and carpel identity. Loss of AG function results in homeotic conversions of stamens into petals and formation of double flowers. In order to present a molecular dissection of a double-flower cultivar in Prunus lannesiana (Rosaceae), we isolated and identified a single-copy gene, AG homolog from two genetically cognate P. lannesiana bearing single and double flowers, respectively. Sequence analysis revealed that the AG homolog, prseag-1, from double flowers showed a 170-bp exon skipping as compared to PrseAG (Prunus serrulata AGAMOUS) from the single flowers. Genomic DNA sequence revealed that abnormal splicing resulted in mutant prseag-1 protein with the C-terminal AG motifs I and II deletions. In addition, protein sequence alignment and phylogenetic analyses revealed that the PrseAG was grouped into the euAG lineage. A semi-quantitative PCR analysis showed that the expression of PrseAG was restricted to reproductive organs of stamens and carpels in single flowers of P. lannesiana 'speciosa', while the prseag-1 mRNA was highly transcribed throughout the petals, stamens, and carpels in double flowers from 'Albo-rosea'. The transgenic Arabidopsis containing 35S::PrseAG displayed extremely early flowering, bigger stamens and carpels and homeotic conversion of petals into staminoid organs, but ectopic expression of prseag-1 could not mimic the phenotypic ectopic expression of PrseAG in Arabidopsis. In general, this study provides evidences to show that double flower 'Albo-rosea' is a putative C functional ag mutant in P. lannesiana.

Switching on Flowers: Transient LEAFY Induction Reveals Novel Aspects of the Regulation of Reproductive Development in Arabidopsis

PubMed Central

Wagner, Doris; Meyerowitz, Elliot M.

2011-01-01

Developmental fate decisions in cell populations fundamentally depend on at least two parameters: a signal that is perceived by the cell and the intrinsic ability of the cell to respond to the signal. The same regulatory logic holds for phase transitions in the life cycle of an organism, for example the switch to reproductive development in flowering plants. Here we have tested the response of the monocarpic plant species Arabidopsis thaliana to a signal that directs flower formation, the plant-specific transcription factor LEAFY (LFY). Using transient steroid-dependent LEAFY (LFY) activation in lfy null mutant Arabidopsis plants, we show that the plant’s competence to respond to the LFY signal changes during development. Very early in the life cycle, the plant is not competent to respond to the signal. Subsequently, transient LFY activation can direct primordia at the flanks of the shoot apical meristem to adopt a floral fate. Finally, the plants acquire competence to initiate the flower-patterning program in response to transient LFY activation. Similar to a perennial life strategy, we did not observe reprogramming of all primordia after perception of the transient signal, instead only a small number of meristems responded, followed by reversion to the prior developmental program. The ability to initiate flower formation and to direct flower patterning in response to transient LFY upregulation was dependent on the known direct LFY target APETALA1 (AP1). Prolonged LFY or activation could alter the developmental gradient and bypass the requirement for AP1. Prolonged high AP1 levels, in turn, can also alter the plants’ competence. Our findings shed light on how plants can fine-tune important phase transitions and developmental responses. PMID:22639600

Phenological behaviour of early spring flowering trees in Spain in response to recent climate changes

NASA Astrophysics Data System (ADS)

Hidalgo-Galvez, M. D.; García-Mozo, H.; Oteros, J.; Mestre, A.; Botey, R.; Galán, C.

2018-04-01

This research reports the phenological trends of four early spring and late winter flowering trees in Spain (south Europe) from a recent period (1986-2012). The studied species were deciduous trees growing in different climatic areas: hazel ( Corylus avellana L.), willow ( Salix alba L.), ash ( Fraxinus angustifolia Vahl.) and white mulberry ( Morus alba L.). We analysed the response to climate and the trends of the following phenophases observed at the field: budburst, leaf unfolding, flowering, fruit ripening, fruit harvesting, leaf colour change and leaf-fall. The study was carried out in 17 sampling sites in the country with the aim of detecting the recent phenological response to the climate of these species, and the possible effect of climate change. We have observed differences in the phenological response to climate depending on each species. Sixty-one percent of studied sites suffered an advance of early spring phenophases, especially budburst on average by -0.67 days and flowering on average by -0.15 days during the studied period, and also in the subsequent fruit ripening and harvesting phases on average by -1.06 days. By contrast, it has been detected that 63% of sampling sites showed a delay in autumn vegetative phases, especially leaf-fall events on average by +1.15 days. The statistic correlation analysis shows in the 55% of the studied localities that phenological advances are the consequence of the increasing trend detected for temperature—being minimum temperature the most influential factor—and in the 52% of them, phenological advances occurred by rainfall variations. In general, leaf unfolding and flowering from these species showed negative correlations in relation to temperature and rainfall, whereas that leaf colour change and leaf-fall presented positive correlations. The results obtained have a great relevance due to the fact that they can be considered as reliable bio-indicators of the impact of the recent climate changes in southern

Fragaria vesca CONSTANS controls photoperiodic flowering and vegetative development.

PubMed

Kurokura, Takeshi; Samad, Samia; Koskela, Elli; Mouhu, Katriina; Hytönen, Timo

2017-10-13

According to the external coincidence model, photoperiodic flowering occurs when CONSTANS (CO) mRNA expression coincides with light in the afternoon of long days (LDs), leading to the activation of FLOWERING LOCUS T (FT). CO has evolved in Brassicaceae from other Group Ia CO-like (COL) proteins which do not control photoperiodic flowering in Arabidopsis. COLs in other species have evolved different functions as floral activators or even as repressors. To understand photoperiodic development in the perennial rosaceous model species woodland strawberry, we functionally characterized FvCO, the only Group Ia COL in its genome. We demonstrate that FvCO has a major role in the photoperiodic control of flowering and vegetative reproduction through runners. FvCO is needed to generate a bimodal rhythm of FvFT1 which encodes a floral activator in the LD accession Hawaii-4: a sharp FvCO expression peak at dawn is followed by the FvFT1 morning peak in LDs indicating possible direct regulation, but additional factors that may include FvGI and FvFKF1 are probably needed to schedule the second FvFT1 peak around dusk. These results demonstrate that although FvCO and FvFT1 play major roles in photoperiodic development, the CO-based external coincidence around dusk is not fully applicable to the woodland strawberry. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Deep analysis of wild Vitis flower transcriptome reveals unexplored genome regions associated with sex specification.

PubMed

Ramos, Miguel Jesus Nunes; Coito, João Lucas; Fino, Joana; Cunha, Jorge; Silva, Helena; de Almeida, Patrícia Gomes; Costa, Maria Manuela Ribeiro; Amâncio, Sara; Paulo, Octávio S; Rocheta, Margarida

2017-01-01

RNA-seq of Vitis during early stages of bud development, in male, female and hermaphrodite flowers, identified new loci outside of annotated gene models, suggesting their involvement in sex establishment. The molecular mechanisms responsible for flower sex specification remain unclear for most plant species. In the case of V. vinifera ssp. vinifera, it is not fully understood what determines hermaphroditism in the domesticated subspecies and male or female flowers in wild dioecious relatives (Vitis vinifera ssp. sylvestris). Here, we describe a de novo assembly of the transcriptome of three flower developmental stages from the three Vitis vinifera flower types. The validation of de novo assembly showed a correlation of 0.825. The main goals of this work were the identification of V. v. sylvestris exclusive transcripts and the characterization of differential gene expression during flower development. RNA from several flower developmental stages was used previously to generate Illumina sequence reads. Through a sequential de novo assembly strategy one comprehensive transcriptome comprising 95,516 non-redundant transcripts was assembled. From this dataset 81,064 transcripts were annotated to V. v. vinifera reference transcriptome and 11,084 were annotated against V. v. vinifera reference genome. Moreover, we found 3368 transcripts that could not be mapped to Vitis reference genome. From all the non-redundant transcripts that were assembled, bioinformatics analysis identified 133 specific of V. v. sylvestris and 516 transcripts differentially expressed among the three flower types. The detection of transcription from areas of the genome not currently annotated suggests active transcription of previously unannotated genomic loci during early stages of bud development.

Molecular analysis of FRIGIDA, a major determinant of natural variation in Arabidopsis flowering time.

PubMed

Johanson, U; West, J; Lister, C; Michaels, S; Amasino, R; Dean, C

2000-10-13

Vernalization, the acceleration of flowering by a long period of cold temperature, ensures that many plants overwinter vegetatively and flower in spring. In Arabidopsis, allelic variation at the FRIGIDA (FRI) locus is a major determinant of natural variation in flowering time. Dominant alleles of FRI confer late flowering, which is reversed to earliness by vernalization. We cloned FRI and analyzed the molecular basis of the allelic variation. Most of the early-flowering ecotypes analyzed carry FRI alleles containing one of two different deletions that disrupt the open reading frame. Loss-of-function mutations at FRI have thus provided the basis for the evolution of many early-flowering ecotypes.

A cucurbit androecy gene reveals how unisexual flowers develop and dioecy emerges.

PubMed

Boualem, Adnane; Troadec, Christelle; Camps, Céline; Lemhemdi, Afef; Morin, Halima; Sari, Marie-Agnes; Fraenkel-Zagouri, Rina; Kovalski, Irina; Dogimont, Catherine; Perl-Treves, Rafael; Bendahmane, Abdelhafid

2015-11-06

Understanding the evolution of sex determination in plants requires identifying the mechanisms underlying the transition from monoecious plants, where male and female flowers coexist, to unisexual individuals found in dioecious species. We show that in melon and cucumber, the androecy gene controls female flower development and encodes a limiting enzyme of ethylene biosynthesis, ACS11. ACS11 is expressed in phloem cells connected to flowers programmed to become female, and ACS11 loss-of-function mutants lead to male plants (androecy). CmACS11 represses the expression of the male promoting gene CmWIP1 to control the development and the coexistence of male and female flowers in monoecious species. Because monoecy can lead to dioecy, we show how a combination of alleles of CmACS11 and CmWIP1 can create artificial dioecy. Copyright © 2015, American Association for the Advancement of Science.

Temporal and intraclonal variation of flowering and pseudovivipary in Poa bulbosa

PubMed Central

Ofir, Micha; Kigel, Jaime

2014-01-01

Background and Aims Versatility in the reproductive development of pseudoviviparous grasses in response to growth conditions is an intriguing reproduction strategy. To better understand this strategy, this study examined variation in flowering and pseudovivipary among populations, co-occurring clones within populations, and among tillers in individual clones of Poa bulbosa, a summer-dormant geophytic grass that reproduces sexually by seed, and asexually by basal tiller bulbs and bulbils formed in proliferated panicles. Methods Clones were collected from 17 populations across a rainfall gradient. Patterns of reproduction were monitored for 11 years in a common garden experiment and related to interannual differences in climatic conditions. Intraclonal variation in flowering and pseudovivipary was studied in a phytotron, under daylengths marginal for flowering induction. Key Results Clones showed large temporal variability in their reproductive behaviour. They flowered in some years but not in others, produced normal or proliferated panicles in different years, or became dormant without flowering. Proliferating clones did not show a distinct time sequence of flowering and proliferation across years. Populations differed in incidence of flowering and proliferation. The proportion of flowering clones increased with decreasing rainfall at the site of population origin, but no consistent relationship was found between flowering and precipitation in the common garden experiment across years. In contrast, flowering decreased at higher temperatures during early growth stages after bulb sprouting. Pulses of soil fertilization greatly increased the proportion of flowering clones and panicle production. High intraclonal tiller heterogeneity was observed, as shown by the divergent developmental fates of daughter plants arising from bulbs from the same parent clone and grown under similar conditions. Panicle proliferation was enhanced by non-inductive 8 h short days, while

Transcript Analysis and Regulative Events during Flower Development in Olive (Olea europaea L.).

PubMed

Alagna, Fiammetta; Cirilli, Marco; Galla, Giulio; Carbone, Fabrizio; Daddiego, Loretta; Facella, Paolo; Lopez, Loredana; Colao, Chiara; Mariotti, Roberto; Cultrera, Nicolò; Rossi, Martina; Barcaccia, Gianni; Baldoni, Luciana; Muleo, Rosario; Perrotta, Gaetano

2016-01-01

The identification and characterization of transcripts involved in flower organ development, plant reproduction and metabolism represent key steps in plant phenotypic and physiological pathways, and may generate high-quality transcript variants useful for the development of functional markers. This study was aimed at obtaining an extensive characterization of the olive flower transcripts, by providing sound information on the candidate MADS-box genes related to the ABC model of flower development and on the putative genetic and molecular determinants of ovary abortion and pollen-pistil interaction. The overall sequence data, obtained by pyrosequencing of four cDNA libraries from flowers at different developmental stages of three olive varieties with distinct reproductive features (Leccino, Frantoio and Dolce Agogia), included approximately 465,000 ESTs, which gave rise to more than 14,600 contigs and approximately 92,000 singletons. As many as 56,700 unigenes were successfully annotated and provided gene ontology insights into the structural organization and putative molecular function of sequenced transcripts and deduced proteins in the context of their corresponding biological processes. Differentially expressed genes with potential regulatory roles in biosynthetic pathways and metabolic networks during flower development were identified. The gene expression studies allowed us to select the candidate genes that play well-known molecular functions in a number of biosynthetic pathways and specific biological processes that affect olive reproduction. A sound understanding of gene functions and regulatory networks that characterize the olive flower is provided.

Transcript Analysis and Regulative Events during Flower Development in Olive (Olea europaea L.)

PubMed Central

Alagna, Fiammetta; Cirilli, Marco; Galla, Giulio; Carbone, Fabrizio; Daddiego, Loretta; Facella, Paolo; Lopez, Loredana; Colao, Chiara; Mariotti, Roberto; Cultrera, Nicolò; Rossi, Martina; Barcaccia, Gianni; Baldoni, Luciana; Muleo, Rosario; Perrotta, Gaetano

2016-01-01

The identification and characterization of transcripts involved in flower organ development, plant reproduction and metabolism represent key steps in plant phenotypic and physiological pathways, and may generate high-quality transcript variants useful for the development of functional markers. This study was aimed at obtaining an extensive characterization of the olive flower transcripts, by providing sound information on the candidate MADS-box genes related to the ABC model of flower development and on the putative genetic and molecular determinants of ovary abortion and pollen-pistil interaction. The overall sequence data, obtained by pyrosequencing of four cDNA libraries from flowers at different developmental stages of three olive varieties with distinct reproductive features (Leccino, Frantoio and Dolce Agogia), included approximately 465,000 ESTs, which gave rise to more than 14,600 contigs and approximately 92,000 singletons. As many as 56,700 unigenes were successfully annotated and provided gene ontology insights into the structural organization and putative molecular function of sequenced transcripts and deduced proteins in the context of their corresponding biological processes. Differentially expressed genes with potential regulatory roles in biosynthetic pathways and metabolic networks during flower development were identified. The gene expression studies allowed us to select the candidate genes that play well-known molecular functions in a number of biosynthetic pathways and specific biological processes that affect olive reproduction. A sound understanding of gene functions and regulatory networks that characterize the olive flower is provided. PMID:27077738

Transcriptomic Analysis Reveals Mechanisms of Sterile and Fertile Flower Differentiation and Development in Viburnum macrocephalum f. keteleeri

PubMed Central

Lu, Zhaogeng; Xu, Jing; Li, Weixing; Zhang, Li; Cui, Jiawen; He, Qingsong; Wang, Li; Jin, Biao

2017-01-01

Sterile and fertile flowers are an important evolutionary developmental (evo-devo) phenotype in angiosperm flowers, playing important roles in pollinator attraction and sexual reproductive success. However, the gene regulatory mechanisms underlying fertile and sterile flower differentiation and development remain largely unknown. Viburnum macrocephalum f. keteleeri, which possesses fertile and sterile flowers in a single inflorescence, is a useful candidate species for investigating the regulatory networks in differentiation and development. We developed a de novo-assembled flower reference transcriptome. Using RNA sequencing (RNA-seq), we compared the expression patterns of fertile and sterile flowers isolated from the same inflorescence over its rapid developmental stages. The flower reference transcriptome consisted of 105,683 non-redundant transcripts, of which 5,675 transcripts showed significant differential expression between fertile and sterile flowers. Combined with morphological and cytological changes between fertile and sterile flowers, we identified expression changes of many genes potentially involved in reproductive processes, phytohormone signaling, and cell proliferation and expansion using RNA-seq and qRT-PCR. In particular, many transcription factors (TFs), including MADS-box family members and ABCDE-class genes, were identified, and expression changes in TFs involved in multiple functions were analyzed and highlighted to determine their roles in regulating fertile and sterile flower differentiation and development. Our large-scale transcriptional analysis of fertile and sterile flowers revealed the dynamics of transcriptional networks and potentially key components in regulating differentiation and development of fertile and sterile flowers in Viburnum macrocephalum f. keteleeri. Our data provide a useful resource for Viburnum transcriptional research and offer insights into gene regulation of differentiation of diverse evo-devo processes in

Flowers under pressure: ins and outs of turgor regulation in development

PubMed Central

Beauzamy, Léna; Nakayama, Naomi; Boudaoud, Arezki

2014-01-01

Background Turgor pressure is an essential feature of plants; however, whereas its physiological importance is unequivocally recognized, its relevance to development is often reduced to a role in cell elongation. Scope This review surveys the roles of turgor in development, the molecular mechanisms of turgor regulation and the methods used to measure turgor and related quantities, while also covering the basic concepts associated with water potential and water flow in plants. Three key processes in flower development are then considered more specifically: flower opening, anther dehiscence and pollen tube growth. Conclusions Many molecular determinants of turgor and its regulation have been characterized, while a number of methods are now available to quantify water potential, turgor and hydraulic conductivity. Data on flower opening, anther dehiscence and lateral root emergence suggest that turgor needs to be finely tuned during development, both spatially and temporally. It is anticipated that a combination of biological experiments and physical measurements will reinforce the existing data and reveal unexpected roles of turgor in development. PMID:25288632

Overexpression of Arabidopsis FLOWERING LOCUS T (FT) gene improves floral development in cassava (Manihot esculenta, Crantz).

PubMed

Adeyemo, O Sarah; Chavarriaga, Paul; Tohme, Joe; Fregene, Martin; Davis, Seth J; Setter, Tim L

2017-01-01

Cassava is a tropical storage-root crop that serves as a worldwide source of staple food for over 800 million people. Flowering is one of the most important breeding challenges in cassava because in most lines flowering is late and non-synchronized, and flower production is sparse. The FLOWERING LOCUS T (FT) gene is pivotal for floral induction in all examined angiosperms. The objective of the current work was to determine the potential roles of the FT signaling system in cassava. The Arabidopsis thaliana FT gene (atFT) was transformed into the cassava cultivar 60444 through Agrobacterium-mediated transformation and was found to be overexpressed constitutively. FT overexpression hastened flower initiation and associated fork-type branching, indicating that cassava has the necessary signaling factors to interact with and respond to the atFT gene product. In addition, overexpression stimulated lateral branching, increased the prolificacy of flower production and extended the longevity of flower development. While FT homologs in some plant species stimulate development of vegetative storage organs, atFT inhibited storage-root development and decreased root harvest index in cassava. These findings collectively contribute to our understanding of flower development in cassava and have the potential for applications in breeding.

Overexpression of Arabidopsis FLOWERING LOCUS T (FT) gene improves floral development in cassava (Manihot esculenta, Crantz)

PubMed Central

Adeyemo, O. Sarah; Chavarriaga, Paul; Tohme, Joe; Fregene, Martin; Davis, Seth J.

2017-01-01

Cassava is a tropical storage-root crop that serves as a worldwide source of staple food for over 800 million people. Flowering is one of the most important breeding challenges in cassava because in most lines flowering is late and non-synchronized, and flower production is sparse. The FLOWERING LOCUS T (FT) gene is pivotal for floral induction in all examined angiosperms. The objective of the current work was to determine the potential roles of the FT signaling system in cassava. The Arabidopsis thaliana FT gene (atFT) was transformed into the cassava cultivar 60444 through Agrobacterium-mediated transformation and was found to be overexpressed constitutively. FT overexpression hastened flower initiation and associated fork-type branching, indicating that cassava has the necessary signaling factors to interact with and respond to the atFT gene product. In addition, overexpression stimulated lateral branching, increased the prolificacy of flower production and extended the longevity of flower development. While FT homologs in some plant species stimulate development of vegetative storage organs, atFT inhibited storage-root development and decreased root harvest index in cassava. These findings collectively contribute to our understanding of flower development in cassava and have the potential for applications in breeding. PMID:28753668

CaAP2 transcription factor is a candidate gene for a flowering repressor and a candidate for controlling natural variation of flowering time in Capsicum annuum.

PubMed

Borovsky, Yelena; Sharma, Vinod K; Verbakel, Henk; Paran, Ilan

2015-06-01

The APETALA2 transcription factor homolog CaAP2 is a candidate gene for a flowering repressor in pepper, as revealed by induced-mutation phenotype, and a candidate underlying a major QTL controlling natural variation in flowering time. To decipher the genetic control of transition to flowering in pepper (Capsicum spp.) and determine the extent of gene function conservation compared to model species, we isolated and characterized several ethyl methanesulfonate (EMS)-induced mutants that vary in their flowering time compared to the wild type. In the present study, we report on the isolation of an early-flowering mutant that flowers after four leaves on the primary stem compared to nine leaves in the wild-type 'Maor'. By genetic mapping and sequencing of putative candidate genes linked to the mutant phenotype, we identified a member of the APETALA2 (AP2) transcription factor family, CaAP2, which was disrupted in the early-flowering mutant. CaAP2 is a likely ortholog of AP2 that functions as a repressor of flowering in Arabidopsis. To test whether CaAP2 has an effect on controlling natural variation in the transition to flowering in pepper, we performed QTL mapping for flowering time in a cross between early and late-flowering C. annuum accessions. We identified a major QTL in a region of chromosome 2 in which CaAP2 was the most significant marker, explaining 52 % of the phenotypic variation of the trait. Sequence comparison of the CaAP2 open reading frames in the two parents used for QTL mapping did not reveal significant variation. In contrast, significant differences in expression level of CaAP2 were detected between near-isogenic lines that differ for the flowering time QTL, supporting the putative function of CaAP2 as a major repressor of flowering in pepper.

Synchrony in the phenology of a culturally iconic spring flower

NASA Astrophysics Data System (ADS)

Sparks, Tim H.; Mizera, Tadeusz; Wójtowicz, Wanda; Tryjanowski, Piotr

2012-03-01

We examine the flowering phenology of the cultural iconic Spring Snowflake Leucojum vernum, a considerable tourist attraction, recorded from two sites in western Poland. Flowering dates at the two sites were closely correlated but about 6 days later at the more natural area. The end of flowering was associated with the start of canopy leafing. Early flowering was related to a longer flowering season which may benefit ecotourism under future climate warming.

Mapping-by-Sequencing Identifies HvPHYTOCHROME C as a Candidate Gene for the early maturity 5 Locus Modulating the Circadian Clock and Photoperiodic Flowering in Barley

PubMed Central

Pankin, Artem; Campoli, Chiara; Dong, Xue; Kilian, Benjamin; Sharma, Rajiv; Himmelbach, Axel; Saini, Reena; Davis, Seth J; Stein, Nils; Schneeberger, Korbinian; von Korff, Maria

2014-01-01

Phytochromes play an important role in light signaling and photoperiodic control of flowering time in plants. Here we propose that the red/far-red light photoreceptor HvPHYTOCHROME C (HvPHYC), carrying a mutation in a conserved region of the GAF domain, is a candidate underlying the early maturity 5 locus in barley (Hordeum vulgare L.). We fine mapped the gene using a mapping-by-sequencing approach applied on the whole-exome capture data from bulked early flowering segregants derived from a backcross of the Bowman(eam5) introgression line. We demonstrate that eam5 disrupts circadian expression of clock genes. Moreover, it interacts with the major photoperiod response gene Ppd-H1 to accelerate flowering under noninductive short days. Our results suggest that HvPHYC participates in transmission of light signals to the circadian clock and thus modulates light-dependent processes such as photoperiodic regulation of flowering. PMID:24996910

The COP9 signalosome interacts with SCF UFO and participates in Arabidopsis flower development.

PubMed

Wang, Xiping; Feng, Suhua; Nakayama, Naomi; Crosby, W L; Irish, Vivian; Deng, Xing Wang; Wei, Ning

2003-05-01

The COP9 signalosome (CSN) is involved in multiple developmental processes. It interacts with SCF ubiquitin ligases and deconjugates Nedd8/Rub1 from cullins (deneddylation). CSN is highly expressed in Arabidopsis floral tissues. To investigate the role of CSN in flower development, we examined the expression pattern of CSN in developing flowers. We report here that two csn1 partially deficient Arabidopsis strains exhibit aberrant development of floral organs, decline of APETALA3 (AP3) expression, and low fertility in addition to defects in shoot and inflorescence meristems. We show that UNUSUAL FLORAL ORGANS (UFO) forms a SCF(UFO) complex, which is associated with CSN in vivo. Genetic interaction analysis indicates that CSN is necessary for the gain-of-function activity of the F-box protein UFO in AP3 activation and in floral organ transformation. Compared with the previously reported csn5 antisense and csn1 null mutants, partial deficiency of CSN1 causes a reduction in the level of CUL1 in the mutant flowers without an obvious defect in CUL1 deneddylation. We conclude that CSN is an essential regulator of Arabidopsis flower development and suggest that CSN regulates Arabidopsis flower development in part by modulating SCF(UFO)-mediated AP3 activation.

Apple flower detection using deep convolutional networks

USDA-ARS?s Scientific Manuscript database

In order to optimize fruit production, a portion of the flowers and fruitlets of apple trees must be removed early in the growing season. The proportion to be removed is determined by the bloom intensity, i.e., the number of flowers present in the orchard. Several automated computer vision systems...

[Double fertilization in flowering plants: 1898-2008].

PubMed

Kordium, E L

2008-01-01

A short review of the results of investigations in the field of plant embryology in vivo and in vitro which are directly connected with the discovery of double fertilization in flowering plants by S.G. Navashin is presented. These results have been obtained by using the methods of electron and fluorescence microscopy, cytophotometry, cultures of isolated ovules, sperms, eggs, and embryo sac central cells. The question on an origin of the female gametophyte of flowering plants, double fertilization, and endosperm are discussed. It is emphasized that the progress in this field is connected mostly with the study of molecular processes which control the development and functioning of a female gametophyte and sporophyte at the early stages of ontogenesis.

Flowers, Beautiful Flowers

ERIC Educational Resources Information Center

School Arts: The Art Education Magazine for Teachers, 2005

2005-01-01

In the lesson described, the middle school students had been studying the artist Georgia O'Keeffe and the history of her work. Students enhanced their flower portraits by adding a matching border and connecting the lesson to other subject areas. Students dissected a flower and drew a small diagram of the flower and labeled the parts. This is an…

Functional Analysis of GmCPDs and Investigation of Their Roles in Flowering

PubMed Central

Wang, Miao; Xu, Xin; Zhang, Xinxin; Sun, Shi; Wu, Cunxiang; Hou, Wensheng; Wang, Qingyu; Han, Tianfu

2015-01-01

The onset of floral development is a pivotal switch in the life of soybean. Brassinosteroids (BRs), a group of steroidal phytohormones with essential roles in plant growth and development, are associated with flowering induction. Genes involved in BR biosynthesis have been studied to a great extent in Arabidopsis, but the study of these genes has been limited in soybean. In this study, four CPD homologs (GmCPDs) catalyzing BR synthesis were isolated from soybean. Transcripts were mainly confined to cotyledons and leaves and were down-regulated in response to exogenous BR. Bioinformatic analysis showed strong sequence and structure similarity between GmCPDs and AtCPD as well as CPDs of other species. Overexpression of GmCPDs in an Arabidopsis BR-deficient mutant rescued the phenotype by restoring the biosynthesis pathway, revealing the functional roles of each GmCPDs in. Except for the rescue of root development, leaf expansion and plant type architecture, GmCPDs in expression also complemented the late flowering phenotype of Arabidopsis mutants deficient in CPD. Further evidence in soybean plants is that the expression levels of GmCPDs in are under photoperiod control in Zigongdongdou, a photoperiod-sensitive variety, and show a sudden peak upon floral meristem initiation. Together with increased GmCPDs in expression in the leaves and cotyledons of photoperiod-insensitive early-maturity soybean, it is clear that GmCPDs in contribute to flowering development and are essential in the early stages of flowering regulation. PMID:25734273

Developmental stages of cultivated strawberry flowers in relation to chilling sensitivity

PubMed Central

Ariza, Maria Teresa; Soria, Carmen; Martínez-Ferri, Elsa

2015-01-01

Environmental factors affecting flower development may limit the yields of fruiting crops worldwide. In temperate regions, chilling temperatures during flower development can compromise fruit production, but their negative effects vary depending on the differing susceptibilities of each developmental stage. The cultivated strawberry (Fragaria× ananassa Duch.) is widely grown worldwide but financial returns are influenced by sudden shifts to chilling temperatures occurring during the cropping cycle. Despite this important limitation, knowledge of F.× ananassa flower development is lacking, in contrast to the diploid wild-type strawberry (F. vesca). In this study we describe steps in floral development of cultivated strawberry and define their vulnerability to chilling temperatures. To achieve this, flower buds from strawberry plants of cv. ‘Camarosa’ were labelled and monitored from bud initiation until anthesis. Description of morphological and functional changes during flower development was based on histological sections and scanning electron microscopy. To determine the impact of low temperatures at different developmental stages, plants carrying buds of different sizes were chilled at 2 °C for 24 h. Several parameters related to male and female gametophyte development were later evaluated in flowers as they approached anthesis. Fragaria× ananassa flower development was divided into 16 stages according to landmark events. These stages were similar to those documented for F. vesca but three new additional intermediate stages were described. Timing of developmental processes was achieved by correlating developmental staging with specific bud sizes and days before anthesis. Time to reach anthesis from early bud stages was 17–18 days. During this period, we detected four critical periods vulnerable to low temperatures. These were mostly related to male gametophyte development but also to injury to female organs at late developmental stages. These results

Methylation of microRNA genes regulates gene expression in bisexual flower development in andromonoecious poplar

PubMed Central

Song, Yuepeng; Tian, Min; Ci, Dong; Zhang, Deqiang

2015-01-01

Previous studies showed sex-specific DNA methylation and expression of candidate genes in bisexual flowers of andromonoecious poplar, but the regulatory relationship between methylation and microRNAs (miRNAs) remains unclear. To investigate whether the methylation of miRNA genes regulates gene expression in bisexual flower development, the methylome, microRNA, and transcriptome were examined in female and male flowers of andromonoecious poplar. 27 636 methylated coding genes and 113 methylated miRNA genes were identified. In the coding genes, 64.5% of the methylated reads mapped to the gene body region; by contrast, 60.7% of methylated reads in miRNA genes mainly mapped in the 5′ and 3′ flanking regions. CHH methylation showed the highest methylation levels and CHG showed the lowest methylation levels. Correlation analysis showed a significant, negative, strand-specific correlation of methylation and miRNA gene expression (r=0.79, P <0.05). The methylated miRNA genes included eight long miRNAs (lmiRNAs) of 24 nucleotides and 11 miRNAs related to flower development. miRNA172b might play an important role in the regulation of bisexual flower development-related gene expression in andromonoecious poplar, via modification of methylation. Gynomonoecious, female, and male poplars were used to validate the methylation patterns of the miRNA172b gene, implying that hyper-methylation in andromonoecious and gynomonoecious poplar might function as an important regulator in bisexual flower development. Our data provide a useful resource for the study of flower development in poplar and improve our understanding of the effect of epigenetic regulation on genes other than protein-coding genes. PMID:25617468

Metatranscriptome Analysis of Fig Flowers Provides Insights into Potential Mechanisms for Mutualism Stability and Gall Induction.

PubMed

Martinson, Ellen O; Hackett, Jeremiah D; Machado, Carlos A; Arnold, A Elizabeth

2015-01-01

A striking property of the mutualism between figs and their pollinating wasps is that wasps consistently oviposit in the inner flowers of the fig syconium, which develop into galls that house developing larvae. Wasps typically do not use the outer ring of flowers, which develop into seeds. To better understand differences between gall and seed flowers, we used a metatranscriptomic approach to analyze eukaryotic gene expression within fig flowers at the time of oviposition choice and early gall development. Consistent with the unbeatable seed hypothesis, we found significant differences in gene expression between gall- and seed flowers in receptive syconia prior to oviposition. In particular, transcripts assigned to flavonoids and carbohydrate metabolism were significantly up-regulated in gall flowers relative to seed flowers. In response to oviposition, gall flowers significantly up-regulated the expression of chalcone synthase, which previously has been connected to gall formation in other plants. We propose several genes encoding proteins with signal peptides or associations with venom of other Hymenoptera as candidate genes for gall initiation or growth. This study simultaneously evaluates the gene expression profile of both mutualistic partners in a plant-insect mutualism and provides insight into a possible stability mechanism in the ancient fig-fig wasp association.

Metatranscriptome Analysis of Fig Flowers Provides Insights into Potential Mechanisms for Mutualism Stability and Gall Induction

PubMed Central

Martinson, Ellen O.; Hackett, Jeremiah D.; Machado, Carlos A.; Arnold, A. Elizabeth

2015-01-01

A striking property of the mutualism between figs and their pollinating wasps is that wasps consistently oviposit in the inner flowers of the fig syconium, which develop into galls that house developing larvae. Wasps typically do not use the outer ring of flowers, which develop into seeds. To better understand differences between gall and seed flowers, we used a metatranscriptomic approach to analyze eukaryotic gene expression within fig flowers at the time of oviposition choice and early gall development. Consistent with the unbeatable seed hypothesis, we found significant differences in gene expression between gall- and seed flowers in receptive syconia prior to oviposition. In particular, transcripts assigned to flavonoids and carbohydrate metabolism were significantly up-regulated in gall flowers relative to seed flowers. In response to oviposition, gall flowers significantly up-regulated the expression of chalcone synthase, which previously has been connected to gall formation in other plants. We propose several genes encoding proteins with signal peptides or associations with venom of other Hymenoptera as candidate genes for gall initiation or growth. This study simultaneously evaluates the gene expression profile of both mutualistic partners in a plant-insect mutualism and provides insight into a possible stability mechanism in the ancient fig-fig wasp association. PMID:26090817

Molecular characterization of FLOWERING LOCUS T-like genes of apple (Malus x domestica Borkh.).

PubMed

Kotoda, Nobuhiro; Hayashi, Hidehiro; Suzuki, Motoko; Igarashi, Megumi; Hatsuyama, Yoshimichi; Kidou, Shin-Ichiro; Igasaki, Tomohiro; Nishiguchi, Mitsuru; Yano, Kanako; Shimizu, Tokurou; Takahashi, Sae; Iwanami, Hiroshi; Moriya, Shigeki; Abe, Kazuyuki

2010-04-01

The two FLOWERING LOCUS T (FT)-like genes of apple (Malus x domestica Borkh.), MdFT1 and MdFT2, have been isolated and characterized. MdFT1 and MdFT2 were mapped, respectively, on distinct linkage groups (LGs) with partial homoeology, LG 12 and LG 4. The expression pattern of MdFT1 and MdFT2 differed in that MdFT1 was expressed mainly in apical buds of fruit-bearing shoots in the adult phase, with little expression in the juvenile tissues, whereas MdFT2 was expressed mainly in reproductive organs, including flower buds and young fruit. On the other hand, both genes had the potential to induce early flowering since transgenic Arabidopsis, which ectopically expressed MdFT1 or MdFT2, flowered earlier than wild-type plants. Furthermore, overexpression of MdFT1 conferred precocious flowering in apple, with altered expression of other endogenous genes, such as MdMADS12. These results suggest that MdFT1 could function to promote flowering by altering the expression of those genes and that, at least, other genes may play an important role as well in the regulation of flowering in apple. The long juvenile period of fruit trees prevents early cropping and efficient breeding. Our findings will be useful information to unveil the molecular mechanism of flowering and to develop methods to shorten the juvenile period in various fruit trees, including apple.

Understanding the unique flowering sequence in Dipsacus fullonum: Evidence from geometrical changes during head development

PubMed Central

Naghiloo, Somayeh; Claßen-Bockhoff, Regine

2017-01-01

The genus Dipsacus is characterized by a remarkable bidirectional flowering sequence and a rare phyllotactic pattern. Considering that flower initiation and flowering sequence may be interconnected, we document the development of the head meristem in Dipsacus fullonum. Our results indicate a gradual change in the geometry of the head meristem beginning with a dome shaped stage, continuing with a remarkable widening in the middle part of the head meristem and ending in a spindle-like form. Quantitative data confirm that meristem expansion is higher in the middle part than at the base of the meristem. Likewise, the size of the flower primordia in the middle part of the young head is significantly larger than at the base soon after initiation. We conclude that the change in the geometry of the meristem and the availability of newly generated space result in the promotion of the middle flowers and the bidirectional flowering sequence at anthesis. Our investigation on phyllotactic patterns reveals a high tendency (30%) of the head meristem to insert or lose parastichies. This finding can also be attributed to changes in the expansion rate of the meristem. Dependent on the spatio-temporal relation between meristem expansion and primordia initiation, either flower primordia are promoted or additional parastichies appear. Our results emphasize the important role of geometry in flower development and phyllotactic pattern formation. PMID:28328952

Cloning, characterization, and expression of xyloglucan endotransglucosylase/hydrolase and expansin genes associated with petal growth and development during carnation flower opening

PubMed Central

Harada, Taro; Torii, Yuka; Morita, Shigeto; Onodera, Reiko; Hara, Yoshinao; Yokoyama, Ryusuke; Nishitani, Kazuhiko; Satoh, Shigeru

2011-01-01

Growth of petal cells is a basis for expansion and morphogenesis (outward bending) of petals during opening of carnation flowers (Dianthus caryophyllus L.). Petal growth progressed through elongation in the early stage, expansion with outward bending in the middle stage, and expansion of the whole area in the late stage of flower opening. In the present study, four cDNAs encoding xyloglucan endotransglucosylase/hydrolase (XTH) (DcXTH1–DcXTH4) and three cDNAs encoding expansin (DcEXPA1–DcEXPA3) were cloned from petals of opening carnation flowers and characterized. Real-time reverse transcription-PCR analyses showed that transcript levels of XTH and expansin genes accumulated differently in floral and vegetative tissues of carnation plants with opening flowers, indicating regulated expression of these genes. DcXTH2 and DcXTH3 transcripts were detected in large quantities in petals as compared with other tissues. DcEXPA1 and DcEXPA2 transcripts were markedly accumulated in petals of opening flowers. The action of XTH in growing petal tissues was confirmed by in situ staining of xyloglucan endotransglucosylase (XET) activity using a rhodamine-labelled xyloglucan nonasaccharide as a substrate. Based on the present findings, it is suggested that two XTH genes (DcXTH2 and DcXTH3) and two expansin genes (DcEXPA1 and DcEXPA2) are associated with petal growth and development during carnation flower opening. PMID:20959626

cDNA cloning and expression of carotenogenic genes during flower development in Gentiana lutea.

PubMed

Zhu, Changfu; Yamamura, Saburo; Koiwa, Hiroyuki; Nishihara, Masashiro; Sandmann, Gerhard

2002-02-01

All cDNAs involved in carotenoid biosynthesis leading to lycopene in yellow petals of Gentiana lutea have been cloned from a cDNA library. They encode a geranylgeranyl pyrophosphate synthase, a phytoene synthase, a phytoene desaturase and a zeta-carotene desaturase. The indicated function of all cDNAs was established by heterologous complementation in Escherichia coli. The amino acid sequences deduced from the cDNAs were between 47.5% and 78.9% identical to those reported for the corresponding enzymes from other higher plants. Southern analysis suggested that the genes for each enzyme probably represent a small multi-gene family. Tissue-specific expression of the genes and expression during flower development was investigated. The expression of the phytoene synthase gene, psy, was enhanced in flowers but transcripts were not detected in stems and leaves by northern blotting. Transcripts of the genes for geranylgeranyl pyrophosphate (ggpps), phytoene desaturase (pds) and zeta-carotene desaturase (zds) were detected in flowers and leaves but not in stems. Analysis of the expression of psy and zds in petals revealed that levels of the transcripts were lowest in young buds and highest in fully open flowers, in parallel with the formation of carotenoids. Obviously, the transcription of these genes control the accumulation of carotenoids during flower development in G. lutea. For pds only a very slight increase of mRNA was found whereas the transcripts of ggpps decreased during flower development.

Irreversible commitment to flowering in two mango cultivars

USDA-ARS?s Scientific Manuscript database

In recent years, the state of Nayarit, Mexico has experienced variations in rainfall distribution and warmer temperatures during the autumn-winter season which have caused erratic flowering of mango. The early-flowering cultivars, such as ‘Ataulfo’, have been less affected than tardy ones such as ‘T...

Methylation of microRNA genes regulates gene expression in bisexual flower development in andromonoecious poplar.

PubMed

Song, Yuepeng; Tian, Min; Ci, Dong; Zhang, Deqiang

2015-04-01

Previous studies showed sex-specific DNA methylation and expression of candidate genes in bisexual flowers of andromonoecious poplar, but the regulatory relationship between methylation and microRNAs (miRNAs) remains unclear. To investigate whether the methylation of miRNA genes regulates gene expression in bisexual flower development, the methylome, microRNA, and transcriptome were examined in female and male flowers of andromonoecious poplar. 27 636 methylated coding genes and 113 methylated miRNA genes were identified. In the coding genes, 64.5% of the methylated reads mapped to the gene body region; by contrast, 60.7% of methylated reads in miRNA genes mainly mapped in the 5' and 3' flanking regions. CHH methylation showed the highest methylation levels and CHG showed the lowest methylation levels. Correlation analysis showed a significant, negative, strand-specific correlation of methylation and miRNA gene expression (r=0.79, P <0.05). The methylated miRNA genes included eight long miRNAs (lmiRNAs) of 24 nucleotides and 11 miRNAs related to flower development. miRNA172b might play an important role in the regulation of bisexual flower development-related gene expression in andromonoecious poplar, via modification of methylation. Gynomonoecious, female, and male poplars were used to validate the methylation patterns of the miRNA172b gene, implying that hyper-methylation in andromonoecious and gynomonoecious poplar might function as an important regulator in bisexual flower development. Our data provide a useful resource for the study of flower development in poplar and improve our understanding of the effect of epigenetic regulation on genes other than protein-coding genes. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

vitisFlower®: Development and Testing of a Novel Android-Smartphone Application for Assessing the Number of Grapevine Flowers per Inflorescence Using Artificial Vision Techniques.

PubMed

Aquino, Arturo; Millan, Borja; Gaston, Daniel; Diago, María-Paz; Tardaguila, Javier

2015-08-28

Grapevine flowering and fruit set greatly determine crop yield. This paper presents a new smartphone application for automatically counting, non-invasively and directly in the vineyard, the flower number in grapevine inflorescence photos by implementing artificial vision techniques. The application, called vitisFlower(®), firstly guides the user to appropriately take an inflorescence photo using the smartphone's camera. Then, by means of image analysis, the flowers in the image are detected and counted. vitisFlower(®) has been developed for Android devices and uses the OpenCV libraries to maximize computational efficiency. The application was tested on 140 inflorescence images of 11 grapevine varieties taken with two different devices. On average, more than 84% of flowers in the captures were found, with a precision exceeding 94%. Additionally, the application's efficiency on four different devices covering a wide range of the market's spectrum was also studied. The results of this benchmarking study showed significant differences among devices, although indicating that the application is efficiently usable even with low-range devices. vitisFlower is one of the first applications for viticulture that is currently freely available on Google Play.

vitisFlower®: Development and Testing of a Novel Android-Smartphone Application for Assessing the Number of Grapevine Flowers per Inflorescence Using Artificial Vision Techniques

PubMed Central

Aquino, Arturo; Millan, Borja; Gaston, Daniel; Diago, María-Paz; Tardaguila, Javier

2015-01-01

Grapevine flowering and fruit set greatly determine crop yield. This paper presents a new smartphone application for automatically counting, non-invasively and directly in the vineyard, the flower number in grapevine inflorescence photos by implementing artificial vision techniques. The application, called vitisFlower®, firstly guides the user to appropriately take an inflorescence photo using the smartphone’s camera. Then, by means of image analysis, the flowers in the image are detected and counted. vitisFlower® has been developed for Android devices and uses the OpenCV libraries to maximize computational efficiency. The application was tested on 140 inflorescence images of 11 grapevine varieties taken with two different devices. On average, more than 84% of flowers in the captures were found, with a precision exceeding 94%. Additionally, the application’s efficiency on four different devices covering a wide range of the market’s spectrum was also studied. The results of this benchmarking study showed significant differences among devices, although indicating that the application is efficiently usable even with low-range devices. vitisFlower is one of the first applications for viticulture that is currently freely available on Google Play. PMID:26343664

Susceptibility of blackberry flower parts to subfreezing temperatures

USDA-ARS?s Scientific Manuscript database

Injury of tight buds, open flowers and green fruit often occur in fruit crops in later winter to early spring frosts. In this study, freezing tolerance of ‘Triple Crown’ blackberry flowers at various maturity ranging from tight bud to green drupe stage was determined using two freezing methods. On...

Flower development as an interplay between dynamical physical fields and genetic networks.

PubMed

Barrio, Rafael Ángel; Hernández-Machado, Aurora; Varea, C; Romero-Arias, José Roberto; Alvarez-Buylla, Elena

2010-10-27

In this paper we propose a model to describe the mechanisms by which undifferentiated cells attain gene configurations underlying cell fate determination during morphogenesis. Despite the complicated mechanisms that surely intervene in this process, it is clear that the fundamental fact is that cells obtain spatial and temporal information that bias their destiny. Our main hypothesis assumes that there is at least one macroscopic field that breaks the symmetry of space at a given time. This field provides the information required for the process of cell differentiation to occur by being dynamically coupled to a signal transduction mechanism that, in turn, acts directly upon the gene regulatory network (GRN) underlying cell-fate decisions within cells. We illustrate and test our proposal with a GRN model grounded on experimental data for cell fate specification during organ formation in early Arabidopsis thaliana flower development. We show that our model is able to recover the multigene configurations characteristic of sepal, petal, stamen and carpel primordial cells arranged in concentric rings, in a similar pattern to that observed during actual floral organ determination. Such pattern is robust to alterations of the model parameters and simulated failures predict altered spatio-temporal patterns that mimic those described for several mutants. Furthermore, simulated alterations in the physical fields predict a pattern equivalent to that found in Lacandonia schismatica, the only flowering species with central stamens surrounded by carpels.

A Multiplex PCR Assay for Differentiating Coconut Rhinoceros Beetle (Coleoptera: Scarabaeidae) From Oriental Flower Beetle (Coleoptera: Scarabaeidae) in Early Life Stages and Excrement.

PubMed

Watanabe, S; Melzer, M J

2017-04-01

The coconut rhinoceros beetle, Oryctes rhinoceros (L.), is a major pest of coconut and other palm trees. An incipient coconut rhinoceros beetle population was recently discovered on the island of Oahu, Hawaii and is currently the target of a large, mutiagency eradication program. Confounding this program is the widespread presence of another scarab beetle on Oahu, the oriental flower beetle, Protaetia orientalis (Gory and Percheron 1833). Eggs, early life stages, and fecal excrement of coconut rhinoceros beetle and oriental flower beetle are morphologically indistinguishable, thereby creating uncertainty when such specimens are discovered in the field. Here, we report the development of a multiplex PCR assay targeting cytochrome oxidase I of coconut rhinoceros beetle and oriental flower beetle that can rapidly detect and distinguish between these insects. This assay also features an internal positive control to ensure DNA of sufficient quantity and quality is used in the assay, increasing its reliability and reducing the chances of false negative results. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Perspectives on MADS-box expression during orchid flower evolution and development.

PubMed

Mondragón-Palomino, Mariana

2013-01-01

The diverse morphology of orchid flowers and their complex, often deceptive strategies to become pollinated have fascinated researchers for a long time. However, it was not until the 20th century that the ontogeny of orchid flowers, the genetic basis of their morphology and the complex phylogeny of Orchidaceae were investigated. In parallel, the improvement of techniques for in vitro seed germination and tissue culture, together with studies on biochemistry, physiology, and cytology supported the progress of what is now a highly productive industry of orchid breeding and propagation. In the present century both basic research in orchid flower evo-devo and the interest for generating novel horticultural varieties have driven the characterization of many members of the MADS-box family encoding key regulators of flower development. This perspective summarizes the picture emerging from these studies and discusses the advantages and limitations of the comparative strategy employed so far. I address the growing role of natural and horticultural mutants in these studies and the emergence of several model species in orchid evo-devo and genomics. In this context, I make a plea for an increasingly integrative approach.

Perspectives on MADS-box expression during orchid flower evolution and development

PubMed Central

Mondragón-Palomino, Mariana

2013-01-01

The diverse morphology of orchid flowers and their complex, often deceptive strategies to become pollinated have fascinated researchers for a long time. However, it was not until the 20th century that the ontogeny of orchid flowers, the genetic basis of their morphology and the complex phylogeny of Orchidaceae were investigated. In parallel, the improvement of techniques for in vitro seed germination and tissue culture, together with studies on biochemistry, physiology, and cytology supported the progress of what is now a highly productive industry of orchid breeding and propagation. In the present century both basic research in orchid flower evo-devo and the interest for generating novel horticultural varieties have driven the characterization of many members of the MADS-box family encoding key regulators of flower development. This perspective summarizes the picture emerging from these studies and discusses the advantages and limitations of the comparative strategy employed so far. I address the growing role of natural and horticultural mutants in these studies and the emergence of several model species in orchid evo-devo and genomics. In this context, I make a plea for an increasingly integrative approach. PMID:24065980

Arabidopsis STERILE APETALA, a multifunctional gene regulating inflorescence, flower, and ovule development

PubMed Central

Byzova, Marina V.; Franken, John; Aarts, Mark G.M.; de Almeida-Engler, Janice; Engler, Gilbert; Mariani, Celestina; Van Lookeren Campagne, Michiel M.; Angenent, Gerco C.

1999-01-01

A recessive mutation in the Arabidopsis STERILE APETALA (SAP) causes severe aberrations in inflorescence and flower and ovule development. In sap flowers, sepals are carpelloid, petals are short and narrow or absent, and anthers are degenerated. Megasporogenesis, the process of meiotic divisions preceding the female gametophyte formation, is arrested in sap ovules during or just after the first meiotic division. More severe aberrations were observed in double mutants between sap and mutant alleles of the floral homeotic gene APETALA2 (AP2) suggesting that both genes are involved in the initiation of female gametophyte development. Together with the organ identity gene AGAMOUS (AG) SAP is required for the maintenance of floral identity acting in a manner similar to APETALA1. In contrast to the outer two floral organs in sap mutant flowers, normal sepals and petals develop in ag/sap double mutants, indicating that SAP negatively regulates AG expression in the perianth whorls. This supposed cadastral function of SAP is supported by in situ hybridization experiments showing ectopic expression of AG in the sap mutant. We have cloned the SAP gene by transposon tagging and revealed that it encodes a novel protein with sequence motifs, that are also present in plant and animal transcription regulators. Consistent with the mutant phenotype, SAP is expressed in inflorescence and floral meristems, floral organ primordia, and ovules. Taken together, we propose that SAP belongs to a new class of transcription regulators essential for a number of processes in Arabidopsis flower development. PMID:10215627

Missing links: the genetic architecture of flowers [correction of flower] and floral diversification.

PubMed

Soltis, Douglas E; Soltis, Pamela S; Albert, Victor A; Oppenheimer, David G; dePamphilis, Claude W; Ma, Hong; Frohlich, Michael W; Theissen, Günter

2002-01-01

To understand the genetic architecture of floral development, including the origin and subsequent diversification of the flower, data are needed not only for a few model organisms but also for gymnosperms, basal angiosperm lineages and early-diverging eudicots. We must link what is known about derived model plants such as Arabidopsis, snapdragon and maize with other angiosperms. To this end, we suggest a massive evolutionary genomics effort focused on the identification and expression patterns of floral genes and elucidation of their expression patterns in 'missing-link' taxa differing in the arrangement, number and organization of floral parts.

The sweet cherry (Prunus avium) FLOWERING LOCUS T gene is expressed during floral bud determination and can promote flowering in a winter-annual Arabidopsis accession.

PubMed

Yarur, Antonia; Soto, Esteban; León, Gabriel; Almeida, Andrea Miyasaka

2016-12-01

FT gene is expressed in leaves and buds and is involved in floral meristem determination and bud development in sweet cherry. In woody fruit perennial trees, floral determination, dormancy and bloom, depends on perception of different environmental and endogenous cues which converge to a systemic signaling gene known as FLOWERING LOCUS T (FT). In long-day flowering plants, FT is expressed in the leaves on long days. The protein travels through the phloem to the shoot apical meristem, where it induces flower determination. In perennial plants, meristem determination and flowering are separated by a dormancy period. Meristem determination takes place in summer, but flowering occurs only after a dormancy period and cold accumulation during winter. The roles of FT are not completely clear in meristem determination, dormancy release, and flowering in perennial plants. We cloned FT from sweet cherry (Prunus avium) and analyzed its expression pattern in leaves and floral buds during spring and summer. Phylogenetic analysis shows high identity of the FT cloned sequence with orthologous genes from other Rosaceae species. Our results show that FT is expressed in both leaves and floral buds and increases when the daylight reached 12 h. The peak in FT expression was coincident with floral meristem identity genes expression and morphological changes typical of floral meristem determination. The Edi-0 Arabidopsis ecotype, which requires vernalization to flower, was transformed with a construct for overexpression of PavFT. These transgenic plants showed an early-flowering phenotype without cold treatment. Our results suggest that FT is involved in floral meristem determination and bud development in sweet cherry. Moreover, we show that FT is expressed in both leaves and floral buds in this species, in contrast to annual plants.

Carpeloidy in flower evolution and diversification: a comparative study in Carica papaya and Arabidopsis thaliana

PubMed Central

Ronse De Craene, Louis; Tréhin, Christophe; Morel, Patrice; Negrutiu, Ioan

2011-01-01

Background and Aims Bisexual flowers of Carica papaya range from highly regular flowers to morphs with various fusions of stamens to the ovary. Arabidopsis thaliana sup1 mutants have carpels replaced by chimeric carpel–stamen structures. Comparative analysis of stamen to carpel conversions in the two different plant systems was used to understand the stage and origin of carpeloidy when derived from stamen tissues, and consequently to understand how carpeloidy contributes to innovations in flower evolution. Methods Floral development of bisexual flowers of Carica was studied by scanning electron microscopy and was compared with teratological sup mutants of A. thaliana. Key Results In Carica development of bisexual flowers was similar to wild (unisexual) forms up to locule initiation. Feminization ranges from fusion of stamen tissue to the gynoecium to complete carpeloidy of antepetalous stamens. In A. thaliana, partial stamen feminization occurs exclusively at the flower apex, with normal stamens forming at the periphery. Such transformations take place relatively late in development, indicating strong developmental plasticity of most stamen tissues. These results are compared with evo-devo theories on flower bisexuality, as derived from unisexual ancestors. The Arabidopsis data highlight possible early evolutionary events in the acquisition of bisexuality by a patchy transformation of stamen parts into female parts linked to a flower axis-position effect. The Carica results highlight tissue-fusion mechanisms in angiosperms leading to carpeloidy once bisexual flowers have evolved. Conclusions We show two different developmental routes leading to stamen to carpel conversions by late re-specification. The process may be a fundamental aspect of flower development that is hidden in most instances by developmental homeostasis. PMID:21504912

Evolving Ideas on the Origin and Evolution of Flowers: New Perspectives in the Genomic Era

PubMed Central

Chanderbali, Andre S.; Berger, Brent A.; Howarth, Dianella G.; Soltis, Pamela S.; Soltis, Douglas E.

2016-01-01

The origin of the flower was a key innovation in the history of complex organisms, dramatically altering Earth’s biota. Advances in phylogenetics, developmental genetics, and genomics during the past 25 years have substantially advanced our understanding of the evolution of flowers, yet crucial aspects of floral evolution remain, such as the series of genetic and morphological changes that gave rise to the first flowers; the factors enabling the origin of the pentamerous eudicot flower, which characterizes ∼70% of all extant angiosperm species; and the role of gene and genome duplications in facilitating floral innovations. A key early concept was the ABC model of floral organ specification, developed by Elliott Meyerowitz and Enrico Coen and based on two model systems, Arabidopsis thaliana and Antirrhinum majus. Yet it is now clear that these model systems are highly derived species, whose molecular genetic-developmental organization must be very different from that of ancestral, as well as early, angiosperms. In this article, we will discuss how new research approaches are illuminating the early events in floral evolution and the prospects for further progress. In particular, advancing the next generation of research in floral evolution will require the development of one or more functional model systems from among the basal angiosperms and basal eudicots. More broadly, we urge the development of “model clades” for genomic and evolutionary-developmental analyses, instead of the primary use of single “model organisms.” We predict that new evolutionary models will soon emerge as genetic/genomic models, providing unprecedented new insights into floral evolution. PMID:27053123

QTL-seq for rapid identification of candidate genes for flowering time in broccoli × cabbage.

PubMed

Shu, Jinshuai; Liu, Yumei; Zhang, Lili; Li, Zhansheng; Fang, Zhiyuan; Yang, Limei; Zhuang, Mu; Zhang, Yangyong; Lv, Honghao

2018-04-01

A major QTL controlling early flowering in broccoli × cabbage was identified by marker analysis and next-generation sequencing, corresponding to GRF6 gene conditioning flowering time in Arabidopsis. Flowering is an important agronomic trait for hybrid production in broccoli and cabbage, but the genetic mechanism underlying this process is unknown. In this study, segregation analysis with BC 1 P1, BC 1 P2, F 2 , and F 2:3 populations derived from a cross between two inbred lines "195" (late-flowering) and "93219" (early flowering) suggested that flowering time is a quantitative trait. Next, employing a next-generation sequencing-based whole-genome QTL-seq strategy, we identified a major genomic region harboring a robust flowering time QTL using an F 2 mapping population, designated Ef2.1 on cabbage chromosome 2 for early flowering. Ef2.1 was further validated by indel (insertion or deletion) marker-based classical QTL mapping, explaining 51.5% (LOD = 37.67) and 54.0% (LOD = 40.5) of the phenotypic variation in F 2 and F 2:3 populations, respectively. Combined QTL-seq and classical QTL analysis narrowed down Ef1.1 to a 228-kb genomic region containing 29 genes. A cabbage gene, Bol024659, was identified in this region, which is a homolog of GRF6, a major gene regulating flowering in Arabidopsis, and was designated BolGRF6. qRT-PCR study of the expression level of BolGRF6 revealed significantly higher expression in the early flowering genotypes. Taken together, our results provide support for BolGRF6 as a possible candidate gene for early flowering in the broccoli line 93219. The identified candidate genomic regions and genes may be useful for molecular breeding to improve broccoli and cabbage flowering times.

Phenological mismatch with abiotic conditions implications for flowering in Arctic plants.

PubMed

Wheeler, Helen C; Høye, Toke T; Schmidt, Niels Martin; Svenning, Jens-Christian; Forchhammer, Mads C

2015-03-01

Although many studies have examined the phenological mismatches between interacting organisms, few have addressed the potential for mismatches between phenology and seasonal weather conditions. In the Arctic, rapid phenological changes in many taxa are occurring in association with earlier snowmelt. The timing of snowmelt is jointly affected by the size of the late winter snowpack and the temperature during the spring thaw. Increased winter snowpack results in delayed snowmelt, whereas higher air temperatures and faster snowmelt advance the timing of snowmelt. Where interannual variation in snowpack is substantial, changes in the timing of snowmelt can be largely uncoupled from changes in air temperature. Using detailed, long-term data on the flowering phenology of four arctic plant species from Zackenberg, Greenland, we investigate whether there is a phenological component to the temperature conditions experienced prior to and during flowering. In particular, we assess the role of timing of flowering in determining pre-flowering exposure to freezing temperatures and to the temperatures-experienced prior to flowering. We then examine the implications of flowering phenology for flower abundance. Earlier snowmelt resulted in greater exposure to freezing conditions, suggesting an increased potential for a mismatch between the timing of flowering and seasonal weather conditions and an increased potential for negative consequences, such as freezing 'damage. We also found a parabolic relationship between the timing of flowering and the temperature experienced during flowering after taking interannual temperature effects into account. If timing of flowering advances to a cooler period of the growing season, this may moderate the effects of a general warming trend across years. Flower abundance was quadratically associated with the timing of flowering, such that both early and late flowering led to lower flower abundance than did intermediate flowering. Our results

Refuges, flower strips, biodiversity and agronomic interest.

PubMed

Roy, Grégory; Wateau, Karine; Legrand, Mickaël; Oste, Sandrine

2008-01-01

Several arthropods are natural predators of pests, and they are able to reduce and control their population development. FREDON Nord Pas-de-Calais (Federation Regionate de Defense contre les Organismes Nuisibles = Regional Federation for Pest Control) has begun for a long time to form farmers to the recognition of beneficial arthropods and to show them their usefulness. These beneficial insects or arachnids are present everywhere, in orchards and even in fields which are areas relatively poor in biodiversity. Adults feed in the flower strips instead larvae and some adults feed on preys such as aphids or caterpillars. Most of the time, beneficial insects can regulate pest but sometimes, in agricultural area, they can't make it early enough and efficiently. Their action begin too late and there biodiversity and number are too low. It's possible to enhance their action by manipulating the ecological infrastructures, like sewing flower strips or installing refuges. Flower strips increase the density of natural enemies and make them be present earlier in the field in order to control pests. Refuges permit beneficial's to spend winter on the spot. So they're able to be active and to grow in number earlier. From 2004 to 2007, on the one hand, FREDON Nord Pas-de-Calais has developed a research program. Its purpose was to inventory practices and also tools and means available and to judge the advisability of using such or such beneficial refuge in orchards. On the second hand, it studied the impact in orchard of refuges on population of beneficial's and the difference there were between manufactured refuges and homemade refuges. Interesting prospects were obtained with some of them. Otherwise, since 2003, FREDON has studied flower strips influence on beneficial population and their impact on pest control. In cabbage fields, results of trials have shown that flower strips lead to a reduction of aphid number under acceptable economic level, up to 50 meters from flower strips

Application of a high-speed breeding technology to apple (Malus × domestica) based on transgenic early flowering plants and marker-assisted selection.

PubMed

Flachowsky, Henryk; Le Roux, Pierre-Marie; Peil, Andreas; Patocchi, Andrea; Richter, Klaus; Hanke, Magda-Viola

2011-10-01

Breeding of apple (Malus × domestica) remains a slow process because of protracted generation cycles. Shortening the juvenile phase to achieve the introgression of traits from wild species into prebreeding material within a reasonable time frame is a great challenge. In this study, we evaluated early flowering transgenic apple lines overexpressing the BpMADS4 gene of silver birch with regard to tree morphology in glasshouse conditions. Based on the results obtained, line T1190 was selected for further analysis and application to fast breeding. The DNA sequences flanking the T-DNA were isolated and the T-DNA integration site was mapped on linkage group 4. The inheritance and correctness of the T-DNA integration were confirmed after meiosis. A crossbred breeding programme was initiated by crossing T1190 with the fire blight-resistant wild species Malus fusca. Transgenic early flowering F(1) seedlings were selected and backcrossed with 'Regia' and 98/6-10 in order to introgress the apple scab Rvi2, Rvi4 and powdery mildew Pl-1, Pl-2 resistance genes and the fire blight resistance quantitative trait locus FB-F7 present in 'Regia'. Three transgenic BC'1 seedlings pyramiding Rvi2, Rvi4 and FB-F7, as well as three other BC'1 seedlings combining Pl-1 and Pl-2, were identified. Thus, the first transgenic early flowering-based apple breeding programme combined with marker-assisted selection was established. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

Co-adaptation of seed dormancy and flowering time in the arable weed Capsella bursa-pastoris (shepherd's purse)

PubMed Central

Toorop, Peter E.; Campos Cuerva, Rafael; Begg, Graham S.; Locardi, Bruna; Squire, Geoff R.; Iannetta, Pietro P. M.

2012-01-01

Background and Aims The duration of the plant life cycle is an important attribute that determines fitness and coexistence of weeds in arable fields. It depends on the timing of two key life-history traits: time from seed dispersal to germination and time from germination to flowering. These traits are components of the time to reproduction. Dormancy results in reduced and delayed germination, thus increasing time to reproduction. Genotypes in the arable seedbank predominantly have short time to flowering. Synergy between reduced seed dormancy and reduced flowering time would create stronger contrasts between genotypes, offering greater adaptation in-field. Therefore, we studied differences in seed dormancy between in-field flowering time genotypes of shepherd's purse. Methods Genotypes with early, intermediate or late flowering time were grown in a glasshouse to provide seed stock for germination tests. Secondary dormancy was assessed by comparing germination before and after dark-incubation. Dormancy was characterized separately for seed myxospermy heteromorphs, observed in each genotype. Seed carbon and nitrogen content and seed mass were determined as indicators of seed filling and resource partitioning associated with dormancy. Key Results Although no differences were observed in primary dormancy, secondary dormancy was weaker among the seeds of early-flowering genotypes. On average, myxospermous seeds showed stronger secondary dormancy than non-myxospermous seeds in all genotypes. Seed filling was similar between the genotypes, but nitrogen partitioning was higher in early-flowering genotypes and in non-myxospermous seeds. Conclusions In shepherd's purse, early flowering and reduced seed dormancy coincide and appear to be linked. The seed heteromorphism contributes to variation in dormancy. Three functional groups of seed dormancy were identified, varying in dormancy depth and nitrate response. One of these groups (FG-III) was distinct for early-flowering

Flower Development as an Interplay between Dynamical Physical Fields and Genetic Networks

PubMed Central

Barrio, Rafael Ángel; Hernández-Machado, Aurora; Varea, C.; Romero-Arias, José Roberto; Álvarez-Buylla, Elena

2010-01-01

In this paper we propose a model to describe the mechanisms by which undifferentiated cells attain gene configurations underlying cell fate determination during morphogenesis. Despite the complicated mechanisms that surely intervene in this process, it is clear that the fundamental fact is that cells obtain spatial and temporal information that bias their destiny. Our main hypothesis assumes that there is at least one macroscopic field that breaks the symmetry of space at a given time. This field provides the information required for the process of cell differentiation to occur by being dynamically coupled to a signal transduction mechanism that, in turn, acts directly upon the gene regulatory network (GRN) underlying cell-fate decisions within cells. We illustrate and test our proposal with a GRN model grounded on experimental data for cell fate specification during organ formation in early Arabidopsis thaliana flower development. We show that our model is able to recover the multigene configurations characteristic of sepal, petal, stamen and carpel primordial cells arranged in concentric rings, in a similar pattern to that observed during actual floral organ determination. Such pattern is robust to alterations of the model parameters and simulated failures predict altered spatio-temporal patterns that mimic those described for several mutants. Furthermore, simulated alterations in the physical fields predict a pattern equivalent to that found in Lacandonia schismatica, the only flowering species with central stamens surrounded by carpels. PMID:21048956

FLOWERING LOCUS C (FLC) regulates development pathways throughout the life cycle of Arabidopsis.

PubMed

Deng, Weiwei; Ying, Hua; Helliwell, Chris A; Taylor, Jennifer M; Peacock, W James; Dennis, Elizabeth S

2011-04-19

FLOWERING LOCUS C (FLC) has a key role in the timing of the initiation of flowering in Arabidopsis. FLC binds and represses two genes that promote flowering, FT and SOC1. We show that FLC binds to many other genes, indicating that it has regulatory roles other than the repression of flowering. We identified 505 FLC binding sites, mostly located in the promoter regions of genes and containing at least one CArG box, the motif known to be associated with MADS-box proteins such as FLC. We examined 40 of the target genes, and 20 showed increased transcript levels in an flc mutant compared with the wild type. Five genes showed decreased expression in the mutant, indicating that FLC binding can result in either transcriptional repression or activation. The genes we identified as FLC targets are involved in developmental pathways throughout the life history of the plant, many of which are associated with reproductive development. FLC is also involved in vegetative development, as evidenced by its binding to SPL15, delaying the progression from juvenile to adult phase. Some of the FLC target genes are also bound by two other MADS-box proteins, AP1 and SEP3, suggesting that MADS-box genes may operate in a network of control at different stages of the life cycle, many ultimately contributing to the development of the reproductive phase of the plant.

Identification of flowering genes in strawberry, a perennial SD plant

PubMed Central

Mouhu, Katriina; Hytönen, Timo; Folta, Kevin; Rantanen, Marja; Paulin, Lars; Auvinen, Petri; Elomaa, Paula

2009-01-01

Background We are studying the regulation of flowering in perennial plants by using diploid wild strawberry (Fragaria vesca L.) as a model. Wild strawberry is a facultative short-day plant with an obligatory short-day requirement at temperatures above 15°C. At lower temperatures, however, flowering induction occurs irrespective of photoperiod. In addition to short-day genotypes, everbearing forms of wild strawberry are known. In 'Baron Solemacher' recessive alleles of an unknown repressor, SEASONAL FLOWERING LOCUS (SFL), are responsible for continuous flowering habit. Although flower induction has a central effect on the cropping potential, the molecular control of flowering in strawberries has not been studied and the genetic flowering pathways are still poorly understood. The comparison of everbearing and short-day genotypes of wild strawberry could facilitate our understanding of fundamental molecular mechanisms regulating perennial growth cycle in plants. Results We have searched homologs for 118 Arabidopsis flowering time genes from Fragaria by EST sequencing and bioinformatics analysis and identified 66 gene homologs that by sequence similarity, putatively correspond to genes of all known genetic flowering pathways. The expression analysis of 25 selected genes representing various flowering pathways did not reveal large differences between the everbearing and the short-day genotypes. However, putative floral identity and floral integrator genes AP1 and LFY were co-regulated during early floral development. AP1 mRNA was specifically accumulating in the shoot apices of the everbearing genotype, indicating its usability as a marker for floral initiation. Moreover, we showed that flowering induction in everbearing 'Baron Solemacher' and 'Hawaii-4' was inhibited by short-day and low temperature, in contrast to short-day genotypes. Conclusion We have shown that many central genetic components of the flowering pathways in Arabidopsis can be identified from

Molecular mechanisms underlying origin and diversification of the angiosperm flower.

PubMed

Theissen, Guenter; Melzer, Rainer

2007-09-01

Understanding the mode and mechanisms of the evolution of the angiosperm flower is a long-standing and central problem of evolutionary biology and botany. It has essentially remained unsolved, however. In contrast, considerable progress has recently been made in our understanding of the genetic basis of flower development in some extant model species. The knowledge that accumulated this way has been pulled together in two major hypotheses, termed the 'ABC model' and the 'floral quartet model'. These models explain how the identity of the different types of floral organs is specified during flower development by homeotic selector genes encoding transcription factors. We intend to explain how the 'ABC model' and the 'floral quartet model' are now guiding investigations that help to understand the origin and diversification of the angiosperm flower. Investigation of orthologues of class B and class C floral homeotic genes in gymnosperms suggest that bisexuality was one of the first innovations during the origin of the flower. The transition from dimer to tetramer formation of floral homeotic proteins after establishment of class E proteins may have increased cooperativity of DNA binding of the transcription factors controlling reproductive growth. That way, we hypothesize, better 'developmental switches' originated that facilitated the early evolution of the flower. Expression studies of ABC genes in basally diverging angiosperm lineages, monocots and basal eudicots suggest that the 'classical' ABC system known from core eudicots originated from a more fuzzy system with fading borders of gene expression and gradual transitions in organ identity, by sharpening of ABC gene expression domains and organ borders. Shifting boundaries of ABC gene expression may have contributed to the diversification of the angiosperm flower many times independently, as may have changes in interactions between ABC genes and their target genes.

Molecular Mechanisms Underlying Origin and Diversification of the Angiosperm Flower

PubMed Central

Theissen, Guenter; Melzer, Rainer

2007-01-01

Background Understanding the mode and mechanisms of the evolution of the angiosperm flower is a long-standing and central problem of evolutionary biology and botany. It has essentially remained unsolved, however. In contrast, considerable progress has recently been made in our understanding of the genetic basis of flower development in some extant model species. The knowledge that accumulated this way has been pulled together in two major hypotheses, termed the ‘ABC model’ and the ‘floral quartet model’. These models explain how the identity of the different types of floral organs is specified during flower development by homeotic selector genes encoding transcription factors. Scope We intend to explain how the ‘ABC model’ and the ‘floral quartet model’ are now guiding investigations that help to understand the origin and diversification of the angiosperm flower. Conclusions Investigation of orthologues of class B and class C floral homeotic genes in gymnosperms suggest that bisexuality was one of the first innovations during the origin of the flower. The transition from dimer to tetramer formation of floral homeotic proteins after establishment of class E proteins may have increased cooperativity of DNA binding of the transcription factors controlling reproductive growth. That way, we hypothesize, better ‘developmental switches’ originated that facilitated the early evolution of the flower. Expression studies of ABC genes in basally diverging angiosperm lineages, monocots and basal eudicots suggest that the ‘classical’ ABC system known from core eudicots originated from a more fuzzy system with fading borders of gene expression and gradual transitions in organ identity, by sharpening of ABC gene expression domains and organ borders. Shifting boundaries of ABC gene expression may have contributed to the diversification of the angiosperm flower many times independently, as may have changes in interactions between ABC genes and their target

BraLTP1, a Lipid Transfer Protein Gene Involved in Epicuticular Wax Deposition, Cell Proliferation and Flower Development in Brassica napus

PubMed Central

Liu, Fang; Xiong, Xiaojuan; Wu, Lei; Fu, Donghui; Hayward, Alice; Zeng, Xinhua; Cao, Yinglong; Wu, Yuhua; Li, Yunjing; Wu, Gang

2014-01-01

Plant non-specific lipid transfer proteins (nsLTPs) constitute large multigene families that possess complex physiological functions, many of which remain unclear. This study isolated and characterized the function of a lipid transfer protein gene, BraLTP1 from Brassica rapa, in the important oilseed crops Brassica napus. BraLTP1 encodes a predicted secretory protein, in the little known VI Class of nsLTP families. Overexpression of BnaLTP1 in B. napus caused abnormal green coloration and reduced wax deposition on leaves and detailed wax analysis revealed 17–80% reduction in various major wax components, which resulted in significant water-loss relative to wild type. BnaLTP1 overexpressing leaves exhibited morphological disfiguration and abaxially curled leaf edges, and leaf cross-sections revealed cell overproliferation that was correlated to increased cytokinin levels (tZ, tZR, iP, and iPR) in leaves and high expression of the cytokinin biosynthsis gene IPT3. BnaLTP1-overexpressing plants also displayed morphological disfiguration of flowers, with early-onset and elongated carpel development and outwardly curled stamen. This was consistent with altered expression of a a number of ABC model genes related to flower development. Together, these results suggest that BraLTP1 is a new nsLTP gene involved in wax production or deposition, with additional direct or indirect effects on cell division and flower development. PMID:25314222

A plant-based chemical genomics screen for the identification of flowering inducers.

PubMed

Fiers, Martijn; Hoogenboom, Jorin; Brunazzi, Alice; Wennekes, Tom; Angenent, Gerco C; Immink, Richard G H

2017-01-01

Floral timing is a carefully regulated process, in which the plant determines the optimal moment to switch from the vegetative to reproductive phase. While there are numerous genes known that control flowering time, little information is available on chemical compounds that are able to influence this process. We aimed to discover novel compounds that are able to induce flowering in the model plant Arabidopsis. For this purpose we developed a plant-based screening platform that can be used in a chemical genomics study. Here we describe the set-up of the screening platform and various issues and pitfalls that need to be addressed in order to perform a chemical genomics screening on Arabidopsis plantlets. We describe the choice for a molecular marker, in combination with a sensitive reporter that's active in plants and is sufficiently sensitive for detection. In this particular screen, the firefly Luciferase marker was used, fused to the regulatory sequences of the floral meristem identity gene APETALA1 (AP1) , which is an early marker for flowering. Using this screening platform almost 9000 compounds were screened, in triplicate, in 96-well plates at a concentration of 25 µM. One of the identified potential flowering inducing compounds was studied in more detail and named Flowering1 (F1). F1 turned out to be an analogue of the plant hormone Salicylic acid (SA) and appeared to be more potent than SA in the induction of flowering. The effect could be confirmed by watering Arabidopsis plants with SA or F1, in which F1 gave a significant reduction in time to flowering in comparison to SA treatment or the control. In this study a chemical genomics screening platform was developed to discover compounds that can induce flowering in Arabidopsis. This platform was used successfully, to identify a compound that can speed-up flowering in Arabidopsis.

Characterization of two rice MADS box genes that control flowering time.

PubMed

Kang, H G; Jang, S; Chung, J E; Cho, Y G; An, G

1997-08-31

Plants contain a variety of the MADS box genes that encode regulatory proteins and play important roles in both the formation of flower meristem and the determination of floral organ identity. We have characterized two flower-specific cDNAs from rice, designated OsMADS7 and OsMADS8. The cDNAs displayed the structure of a typical plant MADS box gene, which consists of the MADS domain, I region, K domain, and C-terminal region. These genes were classified as members of the AGL2 gene family based on sequence homology. The OsMADS7 and 8 proteins were most homologous to OM1 and FBP2, respectively. The OsMADS7 and 8 transcripts were detectable primarily in carpels and also weakly in anthers. During flower development, the OsMADS genes started to express at the young flower stage and the expression continued to the late stage of flower development. The OsMADS7 and 8 genes were mapped on the long arms of the chromosome 8 and 9, respectively. To study the functions of the genes, the cDNA clones were expressed ectopically using the CaMV 35S promoter in a heterologous tobacco plant system. Transgenic plants expressing the OsMADS genes exhibited the phenotype of early flowering and dwarfism. The strength of the phenotypes was proportional to the levels of transgene expression and the phenotypes were co-inherited with the kanamycin resistant gene to the next generation. These results indicate that OsMADS7 and 8 are structurally related to the AGL2 family and are involved in controlling flowering time.

Resource partitioning to male and female flowers of Spinacia oleracea L. in relation to whole-plant monocarpic senescence

PubMed Central

Sklensky, Diane E.; Davies, Peter J.

2011-01-01

Male plants of spinach (Spinacea oleracea L.) senesce following flowering. It has been suggested that nutrient drain by male flowers is insufficient to trigger senescence. The partitioning of radiolabelled photosynthate between vegetative and reproductive tissue was compared in male (staminate) versus female (pistillate) plants. After the start of flowering staminate plants senesce 3 weeks earlier than pistillate plants. Soon after the start of flowering, staminate plants allocated several times as much photosynthate to flowering structures as did pistillate plants. The buds of staminate flowers with developing pollen had the greatest draw of photosynthate. When the staminate plants begin to show senescence 68% of fixed C was allocated to the staminate reproductive structures. In the pistillate plants, export to the developing fruits and young flowers remained near 10% until mid-reproductive development, when it increased to 40%, declining to 27% as the plants started to senesce. These differences were also present on a sink-mass corrected basis. Flowers on staminate spinach plants develop faster than pistillate flowers and have a greater draw of photosynthate than do pistillate flowers and fruits, although for a shorter period. Pistillate plants also produce more leaf area within the inflorescence to sustain the developing fruits. The 14C in the staminate flowers declined due to respiration, especially during pollen maturation; no such loss occurred in pistillate reproductive structures. The partitioning to the reproductive structures correlates with the greater production of floral versus vegetative tissue in staminate plants and their more rapid senescence. As at senescence the leaves still had adequate carbohydrate, the resources are clearly phloem-transported compounds other than carbohydrates. The extent of the resource redistribution to reproductive structures and away from the development of new vegetative sinks, starting very early in the reproductive

Main regulatory pathways, key genes and microRNAs involved in flower formation and development of moso bamboo (Phyllostachys edulis).

PubMed

Ge, Wei; Zhang, Ying; Cheng, Zhanchao; Hou, Dan; Li, Xueping; Gao, Jian

2017-01-01

Moso bamboo is characterized by infrequent sexual reproduction and erratic flowering habit; however, the molecular biology of flower formation and development is not well studied in this species. We studied the molecular regulation mechanisms of moso bamboo development and flowering by selecting three key regulatory pathways: plant-pathogen interaction, plant hormone signal transduction and protein processing in endoplasmic reticulum at different stages of flowering in moso bamboo. We selected PheDof1, PheMADS14 and six microRNAs involved in the three pathways through KEGG pathway and cluster analysis. Subcellular localization, transcriptional activation, Western blotting, in situ hybridization and qRT-PCR were used to further investigate the expression patterns and regulatory roles of pivotal genes at different flower development stages. Differential expression patterns showed that PheDof1, PheMADS14 and six miRNAs may play vital regulatory roles in flower development and floral transition in moso bamboo. Our research paves way for further studies on metabolic regulatory networks and provides insight into the molecular regulation mechanisms of moso bamboo flowering and senescence. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

miRNAs involved in the development and differentiation of fertile and sterile flowers in Viburnum macrocephalum f. keteleeri.

PubMed

Li, Weixing; He, Zhichong; Zhang, Li; Lu, Zhaogeng; Xu, Jing; Cui, Jiawen; Wang, Li; Jin, Biao

2017-10-13

Sterile and fertile flowers are important evolutionary developmental phenotypes in angiosperm flowers. The development of floral organs, critical in angiosperm reproduction, is regulated by microRNAs (miRNAs). However, the mechanisms underpinning the miRNA regulation of the differentiation and development of sterile and fertile flowers remain unclear. Here, based on investigations of the morphological differences between fertile and sterile flowers, we used high-throughput sequencing to characterize the miRNAs in the differentiated floral organs of Viburnum macrocephalum f. keteleeri. We identified 49 known miRNAs and 67 novel miRNAs by small RNA (sRNA) sequencing and bioinformatics analysis, and 17 of these known and novel miRNA precursors were validated by polymerase chain reaction (PCR) and Sanger sequencing. Furthermore, by comparing the sequencing results of two sRNA libraries, we found that 30 known and 39 novel miRNA sequences were differentially expressed, and 35 were upregulated and 34 downregulated in sterile compared with fertile flowers. Combined with their predicted targets, the potential roles of miRNAs in V. macrocephalum f. keteleeri flowers include involvement in floral organogenesis, cell proliferation, hormonal pathways, and stress responses. miRNA precursors and targets were further validated by quantitative real-time PCR (qRT-PCR). Specifically, miR156a-5p, miR156g, and miR156j expression levels were significantly higher in fertile flowers than in sterile flowers, while SPL genes displayed the opposite expression pattern. Considering that the targets of miR156 are predicted to be SPL genes, we propose that miR156 may be involved in the regulation of stamen development in V. macrocephalum f. keteleeri. We identified miRNAs differentially expressed between fertile and sterile flowers in V. macrocephalum f. keteleeri and provided new insights into the important regulatory roles of miRNAs in the differentiation and development of fertile and

Effects of southern highbush blueberry cultivar and treatment threshold on flower thrips populations.

PubMed

Rhodes, Elena M; Liburd, Oscar E; England, Gary K

2012-04-01

In Florida, southern highbush (SHB) blueberries (Vaccinium corymbosum L. x Vaccinium darrowi Camp) are grown for a highly profitable early season fresh market. Flower thrips are the key pest of SHB blueberries, and Frankliniella bispinosa (Morgan) is the most common species found. Flower thrips injure blueberry flowers by feeding and ovipositing in all developing tissues. These injuries can lead to scarring of developing fruit. The objectives of this study were to determine the relationship between thrips and yield in different SHB blueberry cultivars and to determine an action threshold. Experiments were conducted during early spring 2007 and 2008 on four farms; a research farm in Citra, FL; and three commercial farms, two in Hernando Co., FL., and one in Lake Co., FL. At the Citra farm, 'Emerald', 'Jewel', 'Millennia', and 'Star' blueberries were compared in 2007, and all but Star were compared in 2008. On the Hernando and Lake Co. farms, two treatment thresholds (100 and 200 thrips per trap) and an untreated control and four cultivars (Emerald, Jewel, Millennia, and 'Windsor') were compared. Emerald consistently had more thrips per trap and per flower than the other cultivars on all four farms. However, this did not always lead to an increase in fruit injury. Thrips numbers exceeded the threshold on only one farm in 2007, and there was a significantly lower proportion of injured and malformed fruit in the 100 thrips per trap threshold treatment compared with the control on this farm.

FLOWERING LOCUS C (FLC) regulates development pathways throughout the life cycle of Arabidopsis

PubMed Central

Deng, Weiwei; Ying, Hua; Helliwell, Chris A.; Taylor, Jennifer M.; Peacock, W. James; Dennis, Elizabeth S.

2011-01-01

FLOWERING LOCUS C (FLC) has a key role in the timing of the initiation of flowering in Arabidopsis. FLC binds and represses two genes that promote flowering, FT and SOC1. We show that FLC binds to many other genes, indicating that it has regulatory roles other than the repression of flowering. We identified 505 FLC binding sites, mostly located in the promoter regions of genes and containing at least one CArG box, the motif known to be associated with MADS-box proteins such as FLC. We examined 40 of the target genes, and 20 showed increased transcript levels in an flc mutant compared with the wild type. Five genes showed decreased expression in the mutant, indicating that FLC binding can result in either transcriptional repression or activation. The genes we identified as FLC targets are involved in developmental pathways throughout the life history of the plant, many of which are associated with reproductive development. FLC is also involved in vegetative development, as evidenced by its binding to SPL15, delaying the progression from juvenile to adult phase. Some of the FLC target genes are also bound by two other MADS-box proteins, AP1 and SEP3, suggesting that MADS-box genes may operate in a network of control at different stages of the life cycle, many ultimately contributing to the development of the reproductive phase of the plant. PMID:21464308

QTL mapping for flowering-time and photoperiod insensitivity of cotton Gossypium darwinii Watt.

PubMed

Kushanov, Fakhriddin N; Buriev, Zabardast T; Shermatov, Shukhrat E; Turaev, Ozod S; Norov, Tokhir M; Pepper, Alan E; Saha, Sukumar; Ulloa, Mauricio; Yu, John Z; Jenkins, Johnie N; Abdukarimov, Abdusattor; Abdurakhmonov, Ibrokhim Y

2017-01-01

Most wild and semi-wild species of the genus Gossypium are exhibit photoperiod-sensitive flowering. The wild germplasm cotton is a valuable source of genes for genetic improvement of modern cotton cultivars. A bi-parental cotton population segregating for photoperiodic flowering was developed by crossing a photoperiod insensitive irradiation mutant line with its pre-mutagenesis photoperiodic wild-type G. darwinii Watt genotype. Individuals from the F2 and F3 generations were grown with their parental lines and F1 hybrid progeny in the long day and short night summer condition (natural day-length) of Uzbekistan to evaluate photoperiod sensitivity, i.e., flowering-time during the seasons 2008-2009. Through genotyping the individuals of this bi-parental population segregating for flowering-time, linkage maps were constructed using 212 simple-sequence repeat (SSR) and three cleaved amplified polymorphic sequence (CAPS) markers. Six QTLs directly associated with flowering-time and photoperiodic flowering were discovered in the F2 population, whereas eight QTLs were identified in the F3 population. Two QTLs controlling photoperiodic flowering and duration of flowering were common in both populations. In silico annotations of the flanking DNA sequences of mapped SSRs from sequenced cotton (G. hirsutum L.) genome database has identified several potential 'candidate' genes that are known to be associated with regulation of flowering characteristics of plants. The outcome of this research will expand our understanding of the genetic and molecular mechanisms of photoperiodic flowering. Identified markers should be useful for marker-assisted selection in cotton breeding to improve early flowering characteristics.

GmFT2a, a soybean homolog of FLOWERING LOCUS T, is involved in flowering transition and maintenance.

PubMed

Sun, Hongbo; Jia, Zhen; Cao, Dong; Jiang, Bingjun; Wu, Cunxiang; Hou, Wensheng; Liu, Yike; Fei, Zhihong; Zhao, Dazhong; Han, Tianfu

2011-01-01

Flowering reversion can be induced in soybean (Glycine max L. Merr.), a typical short-day (SD) dicot, by switching from SD to long-day (LD) photoperiods. This process may involve florigen, putatively encoded by FLOWERING LOCUS T (FT) in Arabidopsis thaliana. However, little is known about the potential function of soybean FT homologs in flowering reversion. A photoperiod-responsive FT homologue GmFT (renamed as GmFT2a hereafter) was cloned from the photoperiod-sensitive cultivar Zigongdongdou. GmFT2a gene expression under different photoperiods was analyzed by real-time quantitative PCR. In situ hybridization showed direct evidence for its expression during flowering-related processes. GmFT2a was shown to promote flowering using transgenic studies in Arabidopsis and soybean. The effects of photoperiod and temperature on GmFT2a expression were also analyzed in two cultivars with different photoperiod-sensitivities. GmFT2a expression is regulated by photoperiod. Analyses of GmFT2a transcripts revealed a strong correlation between GmFT2a expression and flowering maintenance. GmFT2a transcripts were observed continuously within the vascular tissue up to the shoot apex during flowering. By contrast, transcripts decreased to undetectable levels during flowering reversion. In grafting experiments, the early-flowering, photoperiod-insensitive stock Heihe27 promotes the appearance of GmFT2a transcripts in the shoot apex of scion Zigongdongdou under noninductive LD conditions. The photothermal effects of GmFT2a expression diversity in cultivars with different photoperiod-sensitivities and a hypothesis is proposed. GmFT2a expression is associated with flowering induction and maintenance. Therefore, GmFT2a is a potential target gene for soybean breeding, with the aim of increasing geographic adaptation of this crop.

The microRNA156-SQUAMOSA PROMOTER BINDING PROTEIN-LIKE3 Module Regulates Ambient Temperature-Responsive Flowering via FLOWERING LOCUS T in Arabidopsis1[C][W][OA

PubMed Central

Kim, Jae Joon; Lee, Jeong Hwan; Kim, Wanhui; Jung, Hye Seung; Huijser, Peter; Ahn, Ji Hoon

2012-01-01

The flowering time of plants is affected by modest changes in ambient temperature. However, little is known about the regulation of ambient temperature-responsive flowering by small RNAs. In this study, we show that the microRNA156 (miR156)-SQUAMOSA PROMOTER BINDING PROTEIN-LIKE3 (SPL3) module directly regulates FLOWERING LOCUS T (FT) expression in the leaf to control ambient temperature-responsive flowering. Overexpression of miR156 led to more delayed flowering at a lower ambient temperature (16°C), which was associated with down-regulation of FT and FRUITFULL expression. Among miR156 target genes, SPL3 mRNA levels were mainly reduced, probably because miR156-mediated cleavage of SPL3 mRNA was higher at 16°C. Overexpression of miR156-resistant SPL3 [SPL3(−)] caused early flowering, regardless of the ambient temperature, which was associated with up-regulation of FT and FRUITFULL expression. Reduction of miR156 activity by target mimicry led to a phenotype similar to that of SUC2::rSPL3 plants. FT up-regulation was observed after dexamethasone treatment in GVG-rSPL3 plants. Misexpression and artificial microRNA-mediated suppression of FT in the leaf dramatically altered the ambient temperature-responsive flowering of plants overexpressing miR156 and SPL3(−). Chromatin immunoprecipitation assay showed that the SPL3 protein directly binds to GTAC motifs within the FT promoter. Lesions in TERMINAL FLOWER1, SHORT VEGETATIVE PHASE, and EARLY FLOWERING3 did not alter the expression of miR156 and SPL3. Taken together, our data suggest that the interaction between the miR156-SPL3 module and FT is part of the regulatory mechanism controlling flowering time in response to ambient temperature. PMID:22427344

Flower Development and Perianth Identity Candidate Genes in the Basal Angiosperm Aristolochia fimbriata (Piperales: Aristolochiaceae)

PubMed Central

Pabón-Mora, Natalia; Suárez-Baron, Harold; Ambrose, Barbara A.; González, Favio

2015-01-01

Aristolochia fimbriata (Aristolochiaceae: Piperales) exhibits highly synorganized flowers with a single convoluted structure forming a petaloid perianth that surrounds the gynostemium, putatively formed by the congenital fusion between stamens and the upper portion of the carpels. Here we present the flower development and morphology of A. fimbriata, together with the expression of the key regulatory genes that participate in flower development, particularly those likely controlling perianth identity. A. fimbriata is a member of the magnoliids, and thus gene expression detected for all ABCE MADS-box genes in this taxon, can also help to elucidate patterns of gene expression prior the independent duplications of these genes in eudicots and monocots. Using both floral development and anatomy in combination with the isolation of MADS-box gene homologs, gene phylogenetic analyses and expression studies (both by reverse transcription PCR and in situ hybridization), we present hypotheses on floral organ identity genes involved in the formation of this bizarre flower. We found that most MADS-box genes were expressed in vegetative and reproductive tissues with the exception of AfimSEP2, AfimAGL6, and AfimSTK transcripts that are only found in flowers and capsules but are not detected in leaves. Two genes show ubiquitous expression; AfimFUL that is found in all floral organs at all developmental stages as well as in leaves and capsules, and AfimAG that has low expression in leaves and is found in all floral organs at all stages with a considerable reduction of expression in the limb of anthetic flowers. Our results indicate that expression of AfimFUL is indicative of pleiotropic roles and not of a perianth identity specific function. On the other hand, expression of B-class genes, AfimAP3 and AfimPI, suggests their conserved role in stamen identity and corroborates that the perianth is sepal and not petal-derived. Our data also postulates an AGL6 ortholog as a candidate

Subalpine bumble bee foraging distances and densities in relation to flower availability.

PubMed

Elliott, Susan E

2009-06-01

Bees feed almost exclusively on nectar and pollen from flowers. However, little is known about how food availability limits bee populations, especially in high elevation areas. Foraging distances and relationships between forager densities and resource availability can provide insights into the potential for food limitation in mobile consumer populations. For example, if floral resources are limited, bee consumers should fly farther to forage, and they should be more abundant in areas with more flowers. I estimated subalpine bumble bee foraging distances by calculating forager recapture probabilities at increasing distances from eight marking locations. I measured forager and flower densities over the flowering season in six half-hectare plots. Because subalpine bumble bees have little time to build their colonies, they may forage over short distances and forager density may not be constrained by flower density. However, late in the season, when floral resources dwindle, foraging distances may increase, and there may be stronger relationships between forager and flower densities. Throughout the flowering season, marked bees were primarily found within 100 m (and never >1,000 m) from their original marking location, suggesting that they typically did not fly far to forage. Although the density of early season foraging queens increased with early-season flower density, the density of mid- and late-season workers and males did not vary with flower density. Short foraging distances and no relationships between mid- and late-season forager and flower densities suggest that high elevation bumble bees may have ample floral resources for colony growth reproduction.

Flower orientation enhances pollen transfer in bilaterally symmetrical flowers.

PubMed

Ushimaru, Atushi; Dohzono, Ikumi; Takami, Yasuoki; Hyodo, Fujio

2009-07-01

Zygomorphic flowers are usually more complex than actinomorphic flowers and are more likely to be visited by specialized pollinators. Complex zygomorphic flowers tend to be oriented horizontally. It is hypothesized that a horizontal flower orientation ensures effective pollen transfer by facilitating pollinator recognition (the recognition-facilitation hypothesis) and/or pollinator landing (the landing-control hypothesis). To examine these two hypotheses, we altered the angle of Commelina communis flowers and examined the efficiency of pollen transfer, as well as the behavior of their visitors. We exposed unmanipulated (horizontal-), upward-, and downward-facing flowers to syrphid flies (mostly Episyrphus balteatus), which are natural visitors to C. communis. The frequency of pollinator approaches and landings, as well as the amount of pollen deposited by E. balteatus, decreased for the downward-facing flowers, supporting both hypotheses. The upward-facing flowers received the same numbers of approaches and landings as the unmanipulated flowers, but experienced more illegitimate landings. In addition, the visitors failed to touch the stigmas or anthers on the upward-facing flowers, leading to reduced pollen export and receipt, and supporting the landing-control hypothesis. Collectively, our data suggested that the horizontal orientation of zygomorphic flowers enhances pollen transfer by both facilitating pollinator recognition and controlling pollinator landing position. These findings suggest that zygomorphic flowers which deviate from a horizontal orientation may have lower fitness because of decreased pollen transfer.

Arabidopsis florigen FT binds to diurnally oscillating phospholipids that accelerate flowering.

PubMed

Nakamura, Yuki; Andrés, Fernando; Kanehara, Kazue; Liu, Yu-chi; Dörmann, Peter; Coupland, George

2014-04-04

Arabidopsis FT protein is a component of florigen, which transmits photoperiodic flowering signals from leaf companion cells to the shoot apex. Here, we show that FT specifically binds phosphatidylcholine (PC) in vitro. A transgenic approach to increase PC levels in vivo in the shoot meristem accelerates flowering whereas reduced PC levels delay flowering, demonstrating that PC levels are correlated with flowering time. The early flowering is related to FT activity, because expression of FT-effector genes is increased in these plants. Simultaneous increase of FT and PC in the shoot apical meristem further stimulates flowering, whereas a loss of FT function leads to an attenuation of the effect of increased PC. Specific molecular species of PC oscillate diurnally, and night-dominant species are not the preferred ligands of FT. Elevating night-dominant species during the day delays flowering. We suggest that FT binds to diurnally changing molecular species of PC to promote flowering.

A possible role for flowering locus T-encoding genes in interpreting environmental and internal cues affecting olive (Olea europaea L.) flower induction.

PubMed

Haberman, Amnon; Bakhshian, Ortal; Cerezo-Medina, Sergio; Paltiel, Judith; Adler, Chen; Ben-Ari, Giora; Mercado, Jose Angel; Pliego-Alfaro, Fernando; Lavee, Shimon; Samach, Alon

2017-08-01

Olive (Olea europaea L.) inflorescences, formed in lateral buds, flower in spring. However, there is some debate regarding time of flower induction and inflorescence initiation. Olive juvenility and seasonality of flowering were altered by overexpressing genes encoding flowering locus T (FT). OeFT1 and OeFT2 caused early flowering under short days when expressed in Arabidopsis. Expression of OeFT1/2 in olive leaves and OeFT2 in buds increased in winter, while initiation of inflorescences occurred i n late winter. Trees exposed to an artificial warm winter expressed low levels of OeFT1/2 in leaves and did not flower. Olive flower induction thus seems to be mediated by an increase in FT levels in response to cold winters. Olive flowering is dependent on additional internal factors. It was severely reduced in trees that carried a heavy fruit load the previous season (harvested in November) and in trees without fruit to which cold temperatures were artificially applied in summer. Expression analysis suggested that these internal factors work either by reducing the increase in OeFT1/2 expression or through putative flowering repressors such as TFL1. With expected warmer winters, future consumption of olive oil, as part of a healthy Mediterranean diet, should benefit from better understanding these factors. © 2017 John Wiley & Sons Ltd.

Central role of the flowering repressor ZCCT2 in the redox control of freezing tolerance and the initial development of flower primordia in wheat

PubMed Central

2014-01-01

Background As both abiotic stress response and development are under redox control, it was hypothesised that the pharmacological modification of the redox environment would affect the initial development of flower primordia and freezing tolerance in wheat (Triticum aestivum L.). Results Pharmacologically induced redox changes were monitored in winter (T. ae. ssp. aestivum cv. Cheyenne, Ch) and spring (T. ae. ssp. spelta; Tsp) wheat genotypes grown after germination at 20/17°C for 9 d (chemical treatment: last 3 d), then at 5°C for 21 d (chemical treatment: first 4 d) and subsequently at 20/17°C for 21 d (recovery period). Thiols and their disulphide forms were measured and based on these data reduction potentials were calculated. In the freezing-tolerant Ch the chemical treatments generally increased both the amount of thiol disulphides and the reduction potential after 3 days at 20/17°C. In the freezing-sensitive Tsp a similar effect of the chemicals on these parameters was only observed after the continuation of the treatments for 4 days at 5°C. The applied chemicals slightly decreased root fresh weight and increased freezing tolerance in Ch, whereas they increased shoot fresh weight in Tsp after 4 days at 5°C. As shown after the 3-week recovery at 20/17°C, the initial development of flower primordia was accelerated in Tsp, whereas it was not affected by the treatments in Ch. The chemicals differently affected the expression of ZCCT2 and that of several other genes related to freezing tolerance and initial development of flower primordia in Ch and Tsp after 4 d at 5°C. Conclusions Various redox-altering compounds and osmotica had differential effects on glutathione disulphide content and reduction potential, and consequently on the expression of the flowering repressor ZCCT2 in the winter wheat Ch and the spring wheat Tsp. We propose that the higher expression of ZCCT2 in Ch may be associated with activation of genes of cold acclimation and its lower

Central role of the flowering repressor ZCCT2 in the redox control of freezing tolerance and the initial development of flower primordia in wheat.

PubMed

Gulyás, Zsolt; Boldizsár, Akos; Novák, Aliz; Szalai, Gabriella; Pál, Magda; Galiba, Gábor; Kocsy, Gábor

2014-04-07

As both abiotic stress response and development are under redox control, it was hypothesised that the pharmacological modification of the redox environment would affect the initial development of flower primordia and freezing tolerance in wheat (Triticum aestivum L.). Pharmacologically induced redox changes were monitored in winter (T. ae. ssp. aestivum cv. Cheyenne, Ch) and spring (T. ae. ssp. spelta; Tsp) wheat genotypes grown after germination at 20/17°C for 9 d (chemical treatment: last 3 d), then at 5°C for 21 d (chemical treatment: first 4 d) and subsequently at 20/17°C for 21 d (recovery period). Thiols and their disulphide forms were measured and based on these data reduction potentials were calculated. In the freezing-tolerant Ch the chemical treatments generally increased both the amount of thiol disulphides and the reduction potential after 3 days at 20/17°C. In the freezing-sensitive Tsp a similar effect of the chemicals on these parameters was only observed after the continuation of the treatments for 4 days at 5°C. The applied chemicals slightly decreased root fresh weight and increased freezing tolerance in Ch, whereas they increased shoot fresh weight in Tsp after 4 days at 5°C. As shown after the 3-week recovery at 20/17°C, the initial development of flower primordia was accelerated in Tsp, whereas it was not affected by the treatments in Ch. The chemicals differently affected the expression of ZCCT2 and that of several other genes related to freezing tolerance and initial development of flower primordia in Ch and Tsp after 4 d at 5°C. Various redox-altering compounds and osmotica had differential effects on glutathione disulphide content and reduction potential, and consequently on the expression of the flowering repressor ZCCT2 in the winter wheat Ch and the spring wheat Tsp. We propose that the higher expression of ZCCT2 in Ch may be associated with activation of genes of cold acclimation and its lower expression in Tsp with the

Flowering-Related RING Protein 1 (FRRP1) Regulates Flowering Time and Yield Potential by Affecting Histone H2B Monoubiquitination in Rice (Oryza Sativa).

PubMed

Du, Yiwei; He, Wei; Deng, Changwang; Chen, Xi; Gou, Lanming; Zhu, Fugui; Guo, Wei; Zhang, Jianfu; Wang, Tao

2016-01-01

Flowering time is a critical trait for crops cultivated under various temperature/photoperiod conditions around the world. To understand better the flowering time of rice, we used the vector pTCK303 to produce several lines of RNAi knockdown transgenic rice and investigated their flowering times and other agronomic traits. Among them, the heading date of FRRP1-RNAi knockdown transgenic rice was 23-26 days earlier than that of wild-type plants. FRRP1 is a novel rice gene that encodes a C3HC4-type Really Interesting Novel Gene (RING) finger domain protein. In addition to the early flowering time, FRRP1-RNAi knockdown transgenic rice caused changes on an array of agronomic traits, including plant height, panicle length and grain length. We analyzed the expression of some key genes associated with the flowering time and other agronomic traits in the FRRP1-RNAi knockdown lines and compared with that in wild-type lines. The expression of Hd3a increased significantly, which was the key factor in the early flowering time. Further experiments showed that the level of histone H2B monoubiquitination (H2Bub1) was noticeably reduced in the FRRP1-RNAi knockdown transgenic rice lines compared with wild-type plants and MBP-FRRP1-F1 was capable of self-ubiquitination. The results indicate that Flowering Related RING Protein 1 (FRRP1) is involved in histone H2B monoubiquitination and suggest that FRRP1 functions as an E3 ligase in vivo and in vitro. In conclusion, FRRP1 probably regulates flowering time and yield potential in rice by affecting histone H2B monoubiquitination, which leads to changes in gene expression in multiple processes.

Flowering-Related RING Protein 1 (FRRP1) Regulates Flowering Time and Yield Potential by Affecting Histone H2B Monoubiquitination in Rice (Oryza Sativa)

PubMed Central

Deng, Changwang; Chen, Xi; Gou, Lanming; Zhu, Fugui; Guo, Wei; Zhang, Jianfu; Wang, Tao

2016-01-01

Flowering time is a critical trait for crops cultivated under various temperature/photoperiod conditions around the world. To understand better the flowering time of rice, we used the vector pTCK303 to produce several lines of RNAi knockdown transgenic rice and investigated their flowering times and other agronomic traits. Among them, the heading date of FRRP1-RNAi knockdown transgenic rice was 23–26 days earlier than that of wild-type plants. FRRP1 is a novel rice gene that encodes a C3HC4-type Really Interesting Novel Gene (RING) finger domain protein. In addition to the early flowering time, FRRP1-RNAi knockdown transgenic rice caused changes on an array of agronomic traits, including plant height, panicle length and grain length. We analyzed the expression of some key genes associated with the flowering time and other agronomic traits in the FRRP1-RNAi knockdown lines and compared with that in wild-type lines. The expression of Hd3a increased significantly, which was the key factor in the early flowering time. Further experiments showed that the level of histone H2B monoubiquitination (H2Bub1) was noticeably reduced in the FRRP1-RNAi knockdown transgenic rice lines compared with wild-type plants and MBP-FRRP1-F1 was capable of self-ubiquitination. The results indicate that Flowering Related RING Protein 1 (FRRP1) is involved in histone H2B monoubiquitination and suggest that FRRP1 functions as an E3 ligase in vivo and in vitro. In conclusion, FRRP1 probably regulates flowering time and yield potential in rice by affecting histone H2B monoubiquitination, which leads to changes in gene expression in multiple processes. PMID:26934377

Sexually different morphological, physiological and molecular responses of Fraxinus mandshurica flowers to floral development and chilling stress.

PubMed

Zhu, Zhu; Qi, Fenghui; Yan, Chaofu; Zhan, Yaguang

2016-02-01

Fraxinus mandshurica is considered a dioecious hardwood, and the temporal separation of the maturation of the male and female flowers is one reason that F. mandshurica has become an endangered species in China. Rainfall and low temperature influence pollen formation and dispersal and the blooming of female flowers. Therefore, low fertilization efficiency strongly influences the population of F. mandshurica. Nevertheless, few studies have investigated the sex-specific morphological, physiological and molecular differentiation of F. mandshurica during flowering and its responses to low temperature. In this study, we investigated the sexual differences in the morphological, physiological, and biochemical parameters of F. mandshurica during flowering and determined the physiological and biochemical parameters and expression levels of related genes in response to low-temperature stress induced by exposure to 4 °C (chilling stress) during pollen dispersal and fertilization. Our study supports the hypothesis that male flowers suffer more severe injuries while female flowers are more adaptable to environmental stress during flower development in F. mandshurica. The results showed higher physiological and biochemical levels of malondialdehyde, proline, and soluble sugar, as well as the expression of genes involved in calcium signaling, cold shock and DNA methylation in male flowers compared with female flowers, which suggested that male flowers suffer from more serious peroxidation than female flowers. In contrast, higher antioxidant capacity and FmaCAT expression were detected in female flowers, providing preliminary evidence that male flowers rapidly fade after pollination and further demonstrating that female flowers need a much stronger antioxidant enzyme system to maintain embryonic growth. Most peaks related to physiological and molecular responses were observed at 2-4 h and 8-10 h of exposure to chilling stress in the female and male flowers, respectively

Influence of shading on ornamental and physiological characteristics during flower development of groundcover rose (Rosa hybrida L.)

NASA Astrophysics Data System (ADS)

Hou, Wei; Luo, Ya; Wang, Xiaorong; Chen, Qing; Sun, Bo; Wang, Yan; Liu, Zejing; Tang, Haoru; Zhang, Yong

2018-04-01

The objective of the present investigation was to study the effect of shading on flower quality during flower development and photosynthetic capacity of groundcover rose (Rosa hybrida L.). The results showed that shade significantly increased flower diameter, levels of soluble protein and soluble sugar, total carotenoids content and superoxide dismutase (SOD) activity, while contents of malondialdehyde (MDA) and total anthocyanins in shaded flowers were significantly decreased as compared to sun-exposed flowers. However, no significant changes were observed in petal color parameters L*, a*, b* and C* between sun exposure and shade treatment plants at each flower developmental stage. Therefore, groundcover rose seemed to have the capacity to shade condition through auto-regulation. These results could provide us with a theoretical basis for further application of groundcover rose in the greening of urban spaces and an understanding of the mechanisms behind the changes induced by shade.

The early inflorescence of Arabidopsis thaliana demonstrates positional effects in floral organ growth and meristem patterning.

PubMed

Plackett, Andrew R G; Powers, Stephen J; Phillips, Andy L; Wilson, Zoe A; Hedden, Peter; Thomas, Stephen G

2018-06-01

Linear modelling approaches detected significant gradients in organ growth and patterning across early flowers of the Arabidopsis inflorescence and uncovered evidence of new roles for gibberellin in floral development. Most flowering plants, including the genetic model Arabidopsis thaliana, produce multiple flowers in sequence from a reproductive shoot apex to form a flower spike (inflorescence). The development of individual flowers on an Arabidopsis inflorescence has typically been considered as highly stereotypical and uniform, but this assumption is contradicted by the existence of mutants with phenotypes visible in early flowers only. This phenomenon is demonstrated by mutants partially impaired in the biosynthesis of the phytohormone gibberellin (GA), in which floral organ growth is retarded in the first flowers to be produced but has recovered spontaneously by the 10th flower. We presently lack systematic data from multiple flowers across the Arabidopsis inflorescence to explain such changes. Using mutants of the GA 20-OXIDASE (GA20ox) GA biosynthesis gene family to manipulate endogenous GA levels, we investigated the dynamics of changing floral organ growth across the early Arabidopsis inflorescence (flowers 1-10). Modelling of floral organ lengths identified a significant, GA-independent gradient of increasing stamen length relative to the pistil in the wild-type inflorescence that was separable from other, GA-dependent effects. It was also found that the first flowers exhibited unstable organ patterning in contrast to later flowers and that this instability was prolonged by exogenous GA treatment. These findings indicate that the development of individual flowers is influenced by hitherto unknown factors acting across the inflorescence and also suggest novel functions for GA in floral patterning.

The COMPASS-Like Complex Promotes Flowering and Panicle Branching in Rice1[OPEN

PubMed Central

Wang, Shiliang; Jiang, Haiyang; Cheng, Beijiu

2018-01-01

Flowering time (heading date) and panicle branch number are important agronomic traits that determine yield in rice (Oryza sativa). The activation of flowering requires histone methylation, but the roles of trimethylation of Lys 4 of histone 3 (H3K4me3) in modulating heading date and panicle development are unclear. Here, we showed that the COMPASS-like complex promotes flowering and panicle branching. The rice (Oryza sativa) WD40 protein OsWDR5a interacts with the TRITHORAX-like protein OsTrx1/SET domain group protein 723 (SDG723) to form the core components of the COMPASS-like complex. Plants in which OsWDR5a or OsTrx1 expression was decreased by RNA interference produced fewer secondary branches and less grain and exhibited a delayed heading date under long-day and short-day conditions, whereas loss of OsWDR5a function resulted in embryo lethality. OsWDR5a binds to Early heading date 1 to regulate its H3K4me3 and expression levels. Together, our results show that the COMPASS-like complex promotes flowering and panicle development and suggest that modulation of H3K4me3 levels by the COMPASS-like complex is critical for rice development. PMID:29440594

Delimitation of the Earliness per se D1 (Eps-D1) flowering gene to a subtelomeric chromosomal deletion in bread wheat (Triticum aestivum).

PubMed

Zikhali, Meluleki; Wingen, Luzie U; Griffiths, Simon

2016-01-01

Earliness per se (Eps) genes account for the variation in flowering time when vernalization and photoperiod requirements are satisfied. Genomics and bioinformatics approaches were used to describe allelic variation for 40 Triticum aestivum genes predicted, by synteny with Brachypodium distachyon, to be in the 1DL Eps region. Re-sequencing 1DL genes revealed that varieties carrying early heading alleles at this locus, Spark and Cadenza, carry a subtelomeric deletion including several genes. The equivalent region in Rialto and Avalon is intact. A bimodal distribution in the segregating Spark X Rialto single seed descent (SSD) populations enabled the 1DL QTL to be defined as a discrete Mendelian factor, which we named Eps-D1. Near isogenic lines (NILs) and NIL derived key recombinants between markers flanking Eps-D1 suggest that the 1DL deletion contains the gene(s) underlying Eps-D1. The deletion spans the equivalent of the Triticum monoccocum Eps-A (m) 1 locus, and hence includes MODIFIER OF TRANSCRIPTION 1 (MOT1) and FTSH PROTEASE 4 (FTSH4), the candidates for Eps-A (m) 1. The deletion also contains T. aestivum EARLY FLOWERING 3-D1 (TaELF3-D1) a homologue of the Arabidopsis thaliana circadian clock gene EARLY FLOWERING 3. Eps-D1 is possibly a homologue of Eps-B1 on chromosome 1BL. NILs carrying the Eps-D1 deletion have significantly reduced total TaELF3 expression and altered TaGIGANTEA (TaGI) expression compared with wild type. Altered TaGI expression is consistent with an ELF3 mutant, hence we propose TaELF3-D1 as the more likely candidate for Eps-D1. This is the first direct fine mapping of Eps effect in bread wheat. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

How Do Trees Know When to Flower? Predicting Reproductive Phenology of Douglas-fir with Changing Winter and Spring Temperatures

NASA Astrophysics Data System (ADS)

Prevey, J.; St Clair, B.; Harrington, C.

2016-12-01

Flowering at the right time is one of the primary ways that plants are adapted to their environment. Trees that flower too early risk cold damage to vulnerable new tissues and those that flower too late miss peak resources or may mistime flowering to coincide with other trees, altering outcrossing rates and gene flow. Past observations indicate that temperature cues over winter and spring influence the timing of flowering in many tree species. Understanding these cues is important for predicting how flowering phenology of trees will change with a changing climate.We developed predictive models of flowering for Douglas-fir, an abundant and commercially important tree in the Pacific Northwest. We assembled over 10,000 flowering observations of trees from 11 sites across western Oregon and Washington. We modeled the dates of flowering using hourly temperature data; our models of flowering were adapted from previous models of vegetative budburst and height growth initiation developed for Douglas-fir. Preliminary results show that both chilling (cold) and forcing (warm) temperatures over winter and spring are important determinants of flowering time for Douglas-fir. This suggests that as spring temperatures warm in the future, Douglas-fir across the Pacific Northwest will flower earlier, unless plants experience insufficient chilling over winter, in which case it is possible that Douglas-fir may flower later than in the past, or not flower at all. At one site, Douglas-fir genotypes from different geographic regions flowered in the same order from year to year, indicating that both temperature and heredity influence flowering. Knowledge of the environmental and genetic cues that drive the timing of flowering can help predict how changes in temperature under various climate models could change flowering time across sites. These models may also indicate the geographic areas where future climate could enhance or reduce flowering of Douglas-fir in the future.

Discovery and profiling of novel and conserved microRNAs during flower development in Carya cathayensis via deep sequencing.

PubMed

Wang, Zheng Jia; Huang, Jian Qin; Huang, You Jun; Li, Zheng; Zheng, Bing Song

2012-08-01

Hickory (Carya cathayensis Sarg.) is an economically important woody plant in China, but its long juvenile phase delays yield. MicroRNAs (miRNAs) are critical regulators of genes and important for normal plant development and physiology, including flower development. We used Solexa technology to sequence two small RNA libraries from two floral differentiation stages in hickory to identify miRNAs related to flower development. We identified 39 conserved miRNA sequences from 114 loci belonging to 23 families as well as two novel and ten potential novel miRNAs belonging to nine families. Moreover, 35 conserved miRNA*s and two novel miRNA*s were detected. Twenty miRNA sequences from 49 loci belonging to 11 families were differentially expressed; all were up-regulated at the later stage of flower development in hickory. Quantitative real-time PCR of 12 conserved miRNA sequences, five novel miRNA families, and two novel miRNA*s validated that all were expressed during hickory flower development, and the expression patterns were similar to those detected with Solexa sequencing. Finally, a total of 146 targets of the novel and conserved miRNAs were predicted. This study identified a diverse set of miRNAs that were closely related to hickory flower development and that could help in plant floral induction.

The pea GIGAS gene is a FLOWERING LOCUS T homolog necessary for graft-transmissible specification of flowering but not for responsiveness to photoperiod.

PubMed

Hecht, Valérie; Laurie, Rebecca E; Vander Schoor, Jacqueline K; Ridge, Stephen; Knowles, Claire L; Liew, Lim Chee; Sussmilch, Frances C; Murfet, Ian C; Macknight, Richard C; Weller, James L

2011-01-01

Garden pea (Pisum sativum) was prominent in early studies investigating the genetic control of flowering and the role of mobile flowering signals. In view of recent evidence that genes in the FLOWERING LOCUS T (FT) family play an important role in generating mobile flowering signals, we isolated the FT gene family in pea and examined the regulation and function of its members. Comparison with Medicago truncatula and soybean (Glycine max) provides evidence of three ancient subclades (FTa, FTb, and FTc) likely to be common to most crop and model legumes. Pea FT genes show distinctly different expression patterns with respect to developmental timing, tissue specificity, and response to photoperiod and differ in their activity in transgenic Arabidopsis thaliana, suggesting they may have different functions. We show that the pea FTa1 gene corresponds to the GIGAS locus, which is essential for flowering under long-day conditions and promotes flowering under short-day conditions but is not required for photoperiod responsiveness. Grafting, expression, and double mutant analyses show that GIGAS/FTa1 regulates a mobile flowering stimulus but also provide clear evidence for a second mobile flowering stimulus that is correlated with expression of FTb2 in leaf tissue. These results suggest that induction of flowering by photoperiod in pea results from interactions among several members of a diversified FT family.

Metabolism and development – integration of micro computed tomography data and metabolite profiling reveals metabolic reprogramming from floral initiation to silique development

PubMed Central

Bellaire, Anke; Ischebeck, Till; Staedler, Yannick; Weinhaeuser, Isabell; Mair, Andrea; Parameswaran, Sriram; Ito, Toshiro; Schönenberger, Jürg; Weckwerth, Wolfram

2014-01-01

The interrelationship of morphogenesis and metabolism is a poorly studied phenomenon. The main paradigm is that development is controlled by gene expression. The aim of the present study was to correlate metabolism to early and late stages of flower and fruit development in order to provide the basis for the identification of metabolic adjustment and limitations. A highly detailed picture of morphogenesis is achieved using nondestructive micro computed tomography. This technique was used to quantify morphometric parameters of early and late flower development in an Arabidopsis thaliana mutant with synchronized flower initiation. The synchronized flower phenotype made it possible to sample enough early floral tissue otherwise not accessible for metabolomic analysis. The integration of metabolomic and morphometric data enabled the correlation of metabolic signatures with the process of flower morphogenesis. These signatures changed significantly during development, indicating a pronounced metabolic reprogramming in the tissue. Distinct sets of metabolites involved in these processes were identified and were linked to the findings of previous gene expression studies of flower development. High correlations with basic leucine zipper (bZIP) transcription factors and nitrogen metabolism genes involved in the control of metabolic carbon : nitrogen partitioning were revealed. Based on these observations a model for metabolic adjustment during flower development is proposed. PMID:24350948

Are flowers vulnerable to xylem cavitation during drought?

PubMed

Zhang, Feng-Ping; Brodribb, Timothy J

2017-05-17

Water stress is known to cause xylem cavitation in the leaves, roots and stems of plants, but little is known about the vulnerability of flowers to xylem damage during drought. This is an important gap in our understanding of how and when plants become damaged by water stress. Here we address fundamental questions about if and when flowers suffer cavitation damage, using a new technique of cavitation imaging to resolve the timing of cavitation in water-stressed flower petals compared with neighbouring leaves. Leaves and flowers from a sample of two herbaceous and two woody eudicots were exposed to a severe water stress while the spatial and temporal propagation of embolism through veins was recorded. Although in most cases water potentials inducing 50% embolism of herbaceous flower veins were more negative than neighbouring leaves, there was no significant difference between the average vulnerability of leaves and petals of herbaceous species. In both woody species, petals were more vulnerable to cavitation than leaves, in one case by more than 3 MPa. Early cavitation and subsequent damage of flowers in the two woody species would thus be expected to precede leaf damage during drought. Similar cavitation thresholds of flowers and leaves in the herb sample suggest that cavitation during water shortage in these species will occur simultaneously among aerial tissues. Species-specific differences in the cavitation thresholds of petals provide a new axis of variation that may explain contrasting flowering ecology among plant species. © 2017 The Author(s).

Development and evolution of extreme synorganization in angiosperm flowers and diversity: a comparison of Apocynaceae and Orchidaceae

PubMed Central

Endress, Peter K.

2016-01-01

Background and Aims Apocynaceae and Orchidaceae are two angiosperm families with extreme flower synorganization. They are unrelated, the former in eudicots, the latter in monocots, but they converge in the formation of pollinia and pollinaria, which do not occur in any other angiosperm family, and for which extreme synorganization of floral organs is a precondition. In each family extensive studies on flower development and evolution have been performed; however, newer comparative studies focusing on flower synorganization and involving both families together are lacking. Scope For this study an extensive search through the morphological literature has been conducted. Based on this and my own studies on flowers in various Apocynaceae and Orchidaceae and complex flowers in other angiosperms with scanning electron microscopy and with microtome section series, a review on convergent floral traits in flower development and architecture in the two families is presented. Key Findings There is a tendency of protracted development of synorganized parts in Apocynaceae and Orchidaceae (development of synorganization of two or more organs begins earlier the more accentuated it is at anthesis). Synorganization (or complexity) also paves the way for novel structures. One of the most conspicuous such novel structures in Apocynaceae is the corona, which is not the product of synorganization of existing organs; however, it is probably enhanced by synorganization of other, existing, floral parts. In contrast to synorganized parts, the corona appears developmentally late. Conclusions Synorganization of floral organs may lead to a large number of convergences in clades that are only very distantly related. The convergences that have been highlighted in this comparative study should be developmentally investigated directly in parallel in future studies. PMID:26292994

Unique Crystallization of Fullerenes: Fullerene Flowers

PubMed Central

Kim, Jungah; Park, Chibeom; Song, Intek; Lee, Minkyung; Kim, Hyungki; Choi, Hee Cheul

2016-01-01

Solution-phase crystallization of fullerene molecules strongly depends on the types of solvent and their ratios because solvent molecules are easily included in the crystal lattice and distort its structure. The C70 (solute)–mesitylene (solvent) system yields crystals with various morphologies and structures, such as cubes, tubes, and imperfect rods. Herein, using C60 and C70 dissolved in mesitylene, we present a novel way to grow unique flower-shaped crystals with six symmetric petals. The different solubility of C60 and C70 in mesitylene promotes nucleation of C70 with sixfold symmetry in the early stage, which is followed by co-crystallization of both C60 and C70 molecules, leading to lateral petal growth. Based on the growth mechanism, we obtained more complex fullerene crystals, such as multi-deck flowers and tube-flower complexes, by changing the sequence and parameters of crystallization. PMID:27561446

New methods for regulating flowering time in short-day strawberry

USDA-ARS?s Scientific Manuscript database

Higher percentages of transplants of short-day cultivars 'Chandler', 'Carmine', 'Strawberry Festival', and 'Sweet Charlie' from runner tips plugged in early July rather than the standard time (early August) bloomed in the fall. Nearly 100% of the transplants produced in early July flowered in the f...

DOAP1 Promotes Flowering in the Orchid Dendrobium Chao Praya Smile.

PubMed

Sawettalake, Nunchanoke; Bunnag, Sumontip; Wang, Yanwen; Shen, Lisha; Yu, Hao

2017-01-01

APETALA1 ( AP1 ) encodes a key MADS-box transcription factor that specifies the floral meristem identity on the flank of the inflorescence meristem, and determines the identity of perianth floral organs in the model plant Arabidopsis thaliana . Orchids are members of the Orchidaceae, one of the largest families of angiosperms. Although the expression patterns of a few AP1 -like genes in orchids have been reported, their actual functions in orchid reproductive development are so far largely unknown. In this study, we isolated and characterized an AP1 ortholog, DOAP1 , from Dendrobium Chao Praya Smile. DOAP1 was highly expressed in reproductive tissues, including inflorescence apices and flowers at various developmental stages. Overexpression of DOAP1 resulted in early flowering in Arabidopsis , and was able to rescue the floral organ defects of Arabidopsis ap1 mutants. Moreover, we successfully created transgenic Dendrobium Chao Praya Smile orchids overexpressing DOAP1 , which displayed earlier flowering and earlier termination of inflorescence meristems into floral meristems than wild-type orchids. Our results demonstrate that DOAP1 plays an evolutionarily conserved role in promoting flowering and floral meristem specification in the Orchidaceae family.

DOAP1 Promotes Flowering in the Orchid Dendrobium Chao Praya Smile

PubMed Central

Sawettalake, Nunchanoke; Bunnag, Sumontip; Wang, Yanwen; Shen, Lisha; Yu, Hao

2017-01-01

APETALA1 (AP1) encodes a key MADS-box transcription factor that specifies the floral meristem identity on the flank of the inflorescence meristem, and determines the identity of perianth floral organs in the model plant Arabidopsis thaliana. Orchids are members of the Orchidaceae, one of the largest families of angiosperms. Although the expression patterns of a few AP1-like genes in orchids have been reported, their actual functions in orchid reproductive development are so far largely unknown. In this study, we isolated and characterized an AP1 ortholog, DOAP1, from Dendrobium Chao Praya Smile. DOAP1 was highly expressed in reproductive tissues, including inflorescence apices and flowers at various developmental stages. Overexpression of DOAP1 resulted in early flowering in Arabidopsis, and was able to rescue the floral organ defects of Arabidopsis ap1 mutants. Moreover, we successfully created transgenic Dendrobium Chao Praya Smile orchids overexpressing DOAP1, which displayed earlier flowering and earlier termination of inflorescence meristems into floral meristems than wild-type orchids. Our results demonstrate that DOAP1 plays an evolutionarily conserved role in promoting flowering and floral meristem specification in the Orchidaceae family. PMID:28386268

Polyamines and Flower Development in the Male Sterile Stamenless-2 Mutant of Tomato (Lycopersicon esculentum Mill.) 1

PubMed Central

Rastogi, Rajeev; Sawhney, Vipen K.

1990-01-01

The floral organs of the male sterile stamenless-2 (sl-2/sl-2) mutant of tomato (Lycopersicon esculentum Mill.) contain significantly higher level of polyamines than those of the normal (R Rastogi, VK Sawhney [1990] Plant Physiol 93: 439-445). The effects of putrescine, spermidine and spermine, and three different inhibitors of polyamine biosynthesis on the in vitro development of floral buds of the normal and sl-2/sl-2 mutant were studied. The polyamines were inhibitory to the in vitro growth and development of both the normal and mutant floral buds and they induced abnormal stamen development in normal flowers. The inhibitors of polyamine biosynthesis also inhibited the growth and development of floral organs of the two genotypes, but the normal flowers showed greater sensitivity than the mutant. The inhibitors also promoted the formation of normal-looking pollen in stamens of some mutant flowers. The effect of the inhibitors on polyamine levels was not determined. The polyamine-induced abnormal stamen development in the normal, and the inhibitor-induced production of normal-looking pollen in mutant flowers support the suggestion that the elevated polyamine levels contribute to abnormal stamen development in the sl-2/sl-2 mutant of tomato. Images Figure 3 Figure 5 PMID:16667486

Flowering in Xanthium strumarium: INITIATION AND DEVELOPMENT OF FEMALE INFLORESCENCE AND SEX EXPRESSION.

PubMed

Leonard, M; Kinet, J M; Bodson, M; Havelange, A; Jacqmard, A; Bernier, G

1981-06-01

Vegetative plants of Xanthium strumarium L. grown in long days were induced to flower by exposure to one or several 16-hour dark periods. The distribution of male and female inflorescences on the flowering shoot was described, and a scoring system was designed to assess the development of the female inflorescences. The time of movement of the floral stimulus out of the induced leaf and the timing of action of high temperature were shown to be similar for both the apical male and lateral female inflorescences.Strong photoperiodic induction of the plants favored female sex expression, while maleness was enhanced by exogenous gibberellic acid. The problem of the control of sex expression in Xanthium is discussed in relation to the distribution pattern of male and female inflorescences on the flowering shoot and to the state of the meristem at the time of the arrival of the floral stimulus.

Cloning and characterisation of two CTR1-like genes in Cucurbita pepo: regulation of their expression during male and female flower development.

PubMed

Manzano, Susana; Martínez, Cecilia; Gómez, Pedro; Garrido, Dolores; Jamilena, Manuel

2010-12-01

Ethylene is an essential regulator of flower development in Cucurbita pepo, controlling the sexual expression, and the differentiation and maturation of floral organs. To study the action mechanism of ethylene during the male and female flower development, we have identified two CTR1 homologues from C. pepo, CpCTR1 and CpCTR2, and analysed their expressions during female and male flower development and in response to external treatments with ethylene. CpCTR1 and CpCTR2 share a high homology with plant CTR1-like kinases, but differ from other related kinases such as the Arabidopsis EDR1 and the tomato LeCTR2. The C-terminal ends of both CpCTR1 and CpCTR2 have all the conserved motifs of Ser/Thr kinase domains, including the ATP-binding signature and the protein kinase active site consensus sequence, which suggests that CpCTR1 and CpCTR2 could have the same function as CTR1 in ethylene signalling. The transcripts of both genes were detected in different organs of the plant, including roots, leaves and shoots, but were mostly accumulated in mature flowers. During the development of male and female flowers, CpCTR1 and CpCTR2 expressions were concomitant with ethylene production, which indicates that both genes could be upregulated by ethylene, at least in flowers. Moreover, external treatments with ethylene, although did not alter the expression of these two genes in seedlings and leaves, were able to upregulate their expression in flowers. In the earlier stages of flower development, when ethylene production is very low, the expression of CpCTR1 and CpCTR2 is higher in male floral organs, which agrees with the role of these genes as negative regulators of ethylene signalling, and explain the lower ethylene sensitivity of male flowers in comparison with female flowers. The function of the upregulation of these two genes in later stages of female flower development, when the production of ethylene is also increased, is discussed.

A phenological mid-domain effect in flowering diversity.

PubMed

Morales, Manuel A; Dodge, Gary J; Inouye, David W

2005-01-01

In this paper, we test the mid-domain hypothesis as an explanation for observed patterns of flowering diversity in two sub-alpine communities of insect-pollinated plants. Observed species richness patterns showed an early-season increase in richness, a mid-season peak, and a late-season decrease. We show that a "mid-domain" null model can qualitatively match this pattern of flowering species richness, with R(2) values typically greater than 60%. We find significant or marginally significant departures from expected patterns of diversity for only 3 out of 12 year-site combinations. On the other hand, we do find a consistent pattern of departure when comparing observed versus null-model predicted flowering diversity averaged across years. Our results therefore support the hypothesis that ecological factors shape patterns of flowering phenology, but that the strength or nature of these environmental forcings may differ between years or the two habitats we studied, or may depend on species-specific characteristics of these plant communities. We conclude that mid-domain null models provide an important baseline from which to test departure of expected patterns of flowering diversity across temporal domains. Geometric constraints should be included first in the list of factors that drive seasonal patterns of flowering diversity.

The Role of Temperature in the Growth and Flowering of Geophytes

PubMed Central

Khodorova, Nadezda V.; Boitel-Conti, Michèle

2013-01-01

Among several naturally occurring environmental factors, temperature is considered to play a predominant role in controlling proper growth and flowering in geophytes. Most of them require a “warm-cold-warm” sequence to complete their annual cycle. The temperature optima for flower meristem induction and the early stages of floral organogenesis vary between nine and 25 °C, followed, in the autumn, by a several-week period of lower temperature (4–9 °C), which enables stem elongation and anthesis. The absence of low temperature treatment leads to slow shoot growth in spring and severe flowering disorders. Numerous studies have shown that the effects of the temperature surrounding the underground organs during the autumn-winter period can lead to important physiological changes in plants, but the mechanism that underlies the relationship between cold treatment and growth is still unclear. In this mini-review, we describe experimental data concerning the temperature requirements for flower initiation and development, shoot elongation, aboveground growth and anthesis in bulbous plants. The physiological processes that occur during autumn-winter periods in bulbs (water status, hormonal balance, respiration, carbohydrate mobilization) and how these changes might provoke disorders in stem elongation and flowering are examined. A model describing the relationship between the cold requirement, auxin and gibberellin interactions and the growth response is proposed. PMID:27137399

Development and evolution of extreme synorganization in angiosperm flowers and diversity: a comparison of Apocynaceae and Orchidaceae.

PubMed

Endress, Peter K

2016-04-01

Apocynaceae and Orchidaceae are two angiosperm families with extreme flower synorganization. They are unrelated, the former in eudicots, the latter in monocots, but they converge in the formation of pollinia and pollinaria, which do not occur in any other angiosperm family, and for which extreme synorganization of floral organs is a precondition. In each family extensive studies on flower development and evolution have been performed; however, newer comparative studies focusing on flower synorganization and involving both families together are lacking. For this study an extensive search through the morphological literature has been conducted. Based on this and my own studies on flowers in various Apocynaceae and Orchidaceae and complex flowers in other angiosperms with scanning electron microscopy and with microtome section series, a review on convergent floral traits in flower development and architecture in the two families is presented. There is a tendency of protracted development of synorganized parts in Apocynaceae and Orchidaceae (development of synorganization of two or more organs begins earlier the more accentuated it is at anthesis). Synorganization (or complexity) also paves the way for novel structures. One of the most conspicuous such novel structures in Apocynaceae is the corona, which is not the product of synorganization of existing organs; however, it is probably enhanced by synorganization of other, existing, floral parts. In contrast to synorganized parts, the corona appears developmentally late. Synorganization of floral organs may lead to a large number of convergences in clades that are only very distantly related. The convergences that have been highlighted in this comparative study should be developmentally investigated directly in parallel in future studies. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Expression of B-class MADS-box genes in response to variations in photoperiod is associated with chasmogamous and cleistogamous flower development in Viola philippica.

PubMed

Li, Qiaoxia; Huo, Qingdi; Wang, Juan; Zhao, Jing; Sun, Kun; He, Chaoying

2016-07-07

Some plants develop a breeding system that produces both chasmogamous (CH) and cleistogamous (CL) flowers. However, the underlying molecular mechanism remains elusive. In the present study, we observed that Viola philippica develops CH flowers with short daylight, whereas an extended photoperiod induces the formation of intermediate CL and CL flowers. In response to long daylight, the respective number and size of petals and stamens was lower and smaller than those of normally developed CH flowers, and a minimum of 14-h light induced complete CL flowers that had no petals but developed two stamens of reduced fertility. The floral ABC model indicates that B-class MADS-box genes largely influence the development of the affected two-whorl floral organs; therefore, we focused on characterizing these genes in V. philippica to understand this particular developmental transition. Three such genes were isolated and respectively designated as VpTM6-1, VpTM6-2, and VpPI. These were differentially expressed during floral development (particularly in petals and stamens) and the highest level of expression was observed in CH flowers; significantly low levels were detected in intermediate CL flowers, and the lowest level in CL flowers. The observed variations in the levels of expression after floral induction and organogenesis apparently occurred in response to variations in photoperiod. Therefore, inhibition of the development of petals and stamens might be due to the downregulation of B-class MADS-box gene expression by long daylight, thereby inducing the generation of CL flowers. Our work contributes to the understanding of the adaptive evolutionary formation of dimorphic flowers in plants.

Direct and indirect selection on flowering time, water-use efficiency (WUE, δ 13C), and WUE plasticity to drought in Arabidopsis thaliana

PubMed Central

Kenney, Amanda M; McKay, John K; Richards, James H; Juenger, Thomas E

2014-01-01

Flowering time and water-use efficiency (WUE) are two ecological traits that are important for plant drought response. To understand the evolutionary significance of natural genetic variation in flowering time, WUE, and WUE plasticity to drought in Arabidopsis thaliana, we addressed the following questions: (1) How are ecophysiological traits genetically correlated within and between different soil moisture environments? (2) Does terminal drought select for early flowering and drought escape? (3) Is WUE plasticity to drought adaptive and/or costly? We measured a suite of ecophysiological and reproductive traits on 234 spring flowering accessions of A. thaliana grown in well-watered and season-ending soil drying treatments, and quantified patterns of genetic variation, correlation, and selection within each treatment. WUE and flowering time were consistently positively genetically correlated. WUE was correlated with WUE plasticity, but the direction changed between treatments. Selection generally favored early flowering and low WUE, with drought favoring earlier flowering significantly more than well-watered conditions. Selection for lower WUE was marginally stronger under drought. There were no net fitness costs of WUE plasticity. WUE plasticity (per se) was globally neutral, but locally favored under drought. Strong genetic correlation between WUE and flowering time may facilitate the evolution of drought escape, or constrain independent evolution of these traits. Terminal drought favored drought escape in these spring flowering accessions of A. thaliana. WUE plasticity may be favored over completely fixed development in environments with periodic drought. PMID:25512847

Correspondence between flowers and leaves in terpenoid indole alkaloid metabolism of the phytoplasma-infected Catharanthus roseus plants.

PubMed

Srivastava, Suchi; Pandey, Richa; Kumar, Sushil; Nautiyal, Chandra Shekhar

2014-11-01

Several plants of Catharanthus roseus cv 'leafless inflorescence (lli)' showing phenotype of phytoplasma infection were observed for symptoms of early flowering, virescence, phyllody, and apical clustering of branches. Symptomatic plants were studied for the presence/absence and identity of phytoplasma in flowers. Transcription levels of several genes involved in plants' metabolism and development, accumulation of pharmaceutically important terpenoid indole alkaloids in flowers and leaves and variation in the root-associated microbial flora were examined. The expression profile of 12 genes studied was semi-quantitatively similar in control leaves and phytoplasma-infected leaves and flowers, in agreement with the symptoms of virescence and phyllody in phytoplasma-infected plants. The flowers of phytoplasma-infected plants possessed the TIA profile of leaves and accumulated catharanthine, vindoline, and vincristine and vinblastine in higher concentrations than leaves. The roots of the infected plants displayed lower microbial diversity than those of normal plants. In conclusion, phytoplasma affected the biology of C. roseus lli plants multifariously, it reduced the differences between the metabolite accumulates of the leaves and flowers and restrict the microbial diversity of rhizosphere.

Variation in bioactive compounds, antioxidant enzymes and radical-scavenging activity during flower development of Rosa hybrida

NASA Astrophysics Data System (ADS)

Zhang, Yong; Luo, Ya; Wang, Xiaorong; Chen, Qing; Sun, Bo; Wang, Yan; Liu, Zejing; Tang, Haoru

2018-04-01

Roses are one of the most important ornamental plants and have long been used for edible and medicinal flowers. In the present study, the effect of growth and florescence on changes in anthocyanins, proanthocyanidins (PAs), and the activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxide (APX) and glutathione reductase (GR) of two different colored Rosa hybrida genotypes were determined. Four complementary assays, l,l-diphenyl-2-picrylhydrazyl (DPPH), superoxide and hydroxyl radicals scavenging capacity, ferric reducing antioxidant power (FRAP) assay were used to screen the antioxidant activity of rose flower extracts. Significant variations in bioactive compounds, antioxidant enzymes and radical-scavenging activity were observed at six different developmental stages. No significant difference in antioxidant activity between the white cultivar and red cultivar was found. During flower development, total antioxidant activity and involved compounds decreased, however some antioxidant components such as anthocyanins increased. Overall, rose flowers from flower-bud stage to initiating bloom stage possess the high functional benefit and thus would be the appropriate harvesting stage in the view of nutritional consideration.

Model of white oak flower survival and maturation

Treesearch

David R. Larsen; Robert A. Cecich

1997-01-01

A stochastic model of oak flower dynamics is presented that integrates a number of factors which appear to affect the oak pistillate flower development process. The factors are modeled such that the distribution of the predicted flower populations could have come from the same distribution as the observed flower populations. Factors included in the model are; the range...

Molecular analysis of NOZZLE, a gene involved in pattern formation and early sporogenesis during sex organ development in Arabidopsis thaliana

PubMed Central

Schiefthaler, Ursula; Balasubramanian, Sureshkumar; Sieber, Patrick; Chevalier, David; Wisman, Ellen; Schneitz, Kay

1999-01-01

Sexual reproduction is a salient aspect of plants, and elaborate structures, such as the flowers of angiosperms, have evolved that aid in this process. Within the flower the corresponding sex organs, the anther and the ovule, form the male and female sporangia, the pollen sac and the nucellus, respectively. However, despite their central role for sexual reproduction little is known about the mechanisms that control the establishment of these important structures. Here we present the identification and molecular characterization of the NOZZLE (NZZ) gene in the flowering plant Arabidopsis thaliana. In several nzz mutants the nucellus and the pollen sac fail to form. It indicates that NZZ plays an early and central role in the development of both types of sporangia and that the mechanisms controlling these processes share a crucial factor. In addition, NZZ may have an early function during male and female sporogenesis as well. The evolutionary aspects of these findings are discussed. NZZ encodes a putative protein of unknown function. However, based on sequence analysis we speculate that NZZ is a nuclear protein and possibly a transcription factor. PMID:10500234

Analysis of conifer FLOWERING LOCUS T/TERMINAL FLOWER1-like genes provides evidence for dramatic biochemical evolution in the angiosperm FT lineage.

PubMed

Klintenäs, Maria; Pin, Pierre A; Benlloch, Reyes; Ingvarsson, Pär K; Nilsson, Ove

2012-12-01

In flowering plants, homologs of the Arabidopsis phosphatidylethanolamine-binding protein (PEBP) FLOWERING LOCUS T (FT) are key components in controlling flowering time. We show here that, although FT homologs are found in all angiosperms with completed genome sequences, there is no evidence to date that FT-like genes exist in other groups of plants. Through phylogeny reconstructions and heterologous expression, we examined the biochemical function of the Picea (spruces) and Pinus (pines) PEBP families - two gymnosperm taxa phylogenetically distant from the angiosperms. We have defined a lineage of gymnosperm PEBP genes, termed the FT/TERMINAL FLOWER1 (TFL1)-like genes, that share sequence characteristics with both the angiosperm FT- and TFL1-like clades. When expressed in Arabidopsis, FT/TFL1-like genes repressed flowering, indicating that the proteins are biochemically more similar to the angiosperm TFL1-like proteins than to the FT-like proteins. This suggests that the regulation of the vegetative-to-reproductive switch might differ in gymnosperms compared with angiosperms. Molecular evolution studies suggest that plasticity at exon 4 contributes to the divergence of FT-like function in floral promotion. In addition, the presence of FT-like genes in basal angiosperms indicates that the FT-like function emerged at an early stage during the evolution of flowering plants as a means to regulate flowering time. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

Genomic Approach to Study Floral Development Genes in Rosa sp.

PubMed Central

Chauvet, Aurélie; Maene, Marion; Pécrix, Yann; Yang, Shu-Hua; Jeauffre, Julien; Thouroude, Tatiana; Boltz, Véronique; Martin-Magniette, Marie-Laure; Janczarski, Stéphane; Legeai, Fabrice; Renou, Jean-Pierre; Vergne, Philippe; Le Bris, Manuel; Foucher, Fabrice; Bendahmane, Mohammed

2011-01-01

Cultivated for centuries, the varieties of rose have been selected based on a number of flower traits. Understanding the genetic and molecular basis that contributes to these traits will impact on future improvements for this economically important ornamental plant. In this study, we used scanning electron microscopy and sections of meristems and flowers to establish a precise morphological calendar from early rose flower development stages to senescing flowers. Global gene expression was investigated from floral meristem initiation up to flower senescence in three rose genotypes exhibiting contrasted floral traits including continuous versus once flowering and simple versus double flower architecture, using a newly developed Affymetrix microarray (Rosa1_Affyarray) tool containing sequences representing 4765 unigenes expressed during flower development. Data analyses permitted the identification of genes associated with floral transition, floral organs initiation up to flower senescence. Quantitative real time PCR analyses validated the mRNA accumulation changes observed in microarray hybridizations for a selection of 24 genes expressed at either high or low levels. Our data describe the early flower development stages in Rosa sp, the production of a rose microarray and demonstrate its usefulness and reliability to study gene expression during extensive development phases, from the vegetative meristem to the senescent flower. PMID:22194838

Blob Flowers.

ERIC Educational Resources Information Center

Canfield, Elaine

2003-01-01

Describes an art project called blob flowers in which fifth-grade students created pictures of flowers using watercolor and markers. Explains that the lesson incorporates ideas from art and science. Discusses in detail how the students created their flowers. (CMK)

A Factor Linking Floral Organ Identity and Growth Revealed by Characterization of the Tomato Mutant unfinished flower development (ufd).

PubMed

Poyatos-Pertíñez, Sandra; Quinet, Muriel; Ortíz-Atienza, Ana; Yuste-Lisbona, Fernando J; Pons, Clara; Giménez, Estela; Angosto, Trinidad; Granell, Antonio; Capel, Juan; Lozano, Rafael

2016-01-01

Floral organogenesis requires coordinated interactions between genes specifying floral organ identity and those regulating growth and size of developing floral organs. With the aim to isolate regulatory genes linking both developmental processes (i.e., floral organ identity and growth) in the tomato model species, a novel mutant altered in the formation of floral organs was further characterized. Under normal growth conditions, floral organ primordia of mutant plants were correctly initiated, however, they were unable to complete their development impeding the formation of mature and fertile flowers. Thus, the growth of floral buds was blocked at an early stage of development; therefore, we named this mutant as unfinished flower development ( ufd ). Genetic analysis performed in a segregating population of 543 plants showed that the abnormal phenotype was controlled by a single recessive mutation. Global gene expression analysis confirmed that several MADS-box genes regulating floral identity as well as other genes participating in cell division and different hormonal pathways were affected in their expression patterns in ufd mutant plants. Moreover, ufd mutant inflorescences showed higher hormone contents, particularly ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) and strigol compared to wild type. Such results indicate that UFD may have a key function as positive regulator of the development of floral primordia once they have been initiated in the four floral whorls. This function should be performed by affecting the expression of floral organ identity and growth genes, together with hormonal signaling pathways.

Eating flowers? Exploring attitudes and consumers' representation of edible flowers.

PubMed

Rodrigues, H; Cielo, D P; Goméz-Corona, C; Silveira, A A S; Marchesan, T A; Galmarini, M V; Richards, N S P S

2017-10-01

Edible flowers have gained more attention in recent years thanks to their perceived health benefits. Despite this attention, it seems that edible flowers are not popularized for consumption in South America, being considered unfamiliar for some cultures from this continent. In this context, the general goal of the present study was to investigate the three dimensions of social representation theory, the representational field, the information and the attitude of the two conditions of edible flowers: a more general "food made with flowers" and more directional product "yoghurt made with flowers", using Brazilian consumers. To achieve this goal, a free word association task was applied. A total of 549 consumers participated in this study. Participants were divided into two conditions, in which the inductor expressions for the free word association task changed: (a) food products made with flowers and (b) yoghurt made with flowers. Results showed a very positive attitude to both situations, and consumers associated Food products made with flowers to "health care" while the central core of yoghurt made with flowers reflected the innovative condition of this product, supported here by their unpredictable character (information generated). Copyright © 2017 Elsevier Ltd. All rights reserved.

A Conserved Cytochrome P450 Evolved in Seed Plants Regulates Flower Maturation.

PubMed

Liu, Zhenhua; Boachon, Benoît; Lugan, Raphaël; Tavares, Raquel; Erhardt, Mathieu; Mutterer, Jérôme; Demais, Valérie; Pateyron, Stéphanie; Brunaud, Véronique; Ohnishi, Toshiyuki; Pencik, Ales; Achard, Patrick; Gong, Fan; Hedden, Peter; Werck-Reichhart, Danièle; Renault, Hugues

2015-12-07

Global inspection of plant genomes identifies genes maintained in low copies across taxa and under strong purifying selection, which are likely to have essential functions. Based on this rationale, we investigated the function of the low-duplicated CYP715 cytochrome P450 gene family that appeared early in seed plants and evolved under strong negative selection. Arabidopsis CYP715A1 showed a restricted tissue-specific expression in the tapetum of flower buds and in the anther filaments upon anthesis. cyp715a1 insertion lines showed a strong defect in petal development, and transient alteration of pollen intine deposition. Comparative expression analysis revealed the downregulated expression of genes involved in pollen development, cell wall biogenesis, hormone homeostasis, and floral sesquiterpene biosynthesis, especially TPS21 and several key genes regulating floral development such as MYB21, MYB24, and MYC2. Accordingly, floral sesquiterpene emission was suppressed in the cyp715a1 mutants. Flower hormone profiling, in addition, indicated a modification of gibberellin homeostasis and a strong disturbance of the turnover of jasmonic acid derivatives. Petal growth was partially restored by the active gibberellin GA3 or the functional analog of jasmonoyl-isoleucine, coronatine. CYP715 appears to function as a key regulator of flower maturation, synchronizing petal expansion and volatile emission. It is thus expected to be an important determinant of flower-insect interaction. Copyright © 2015 The Author. Published by Elsevier Inc. All rights reserved.

Variation in Time of Flowering and Seed Dispersal of Eastern Cottonwood In the Lower Mississippi Valley

Treesearch

Robert E. Farmer

1966-01-01

Flowering of Populus deItoides Bartr. occurred from early March to early April; differences between trees within stands accounted for 98 percent of the significant variation in dates. High correlation (r = .91 to .96) between 1963 and 1964 dates of individual trees indicated that trees within stands flower in a predictable sequence. Seed dispersal...

Neotropical Copestylum Macquart (Diptera: Syrphidae) Breeding in Fruits and Flowers, Including 7 New Species

PubMed Central

Ricarte, Antonio; Marcos-García, M. Ángeles; Hancock, E. Geoffrey; Rotheray, Graham E.

2015-01-01

Ten species of Copestylum (Diptera: Syrphidae) were reared from fruits and flowers in Costa Rica, Ecuador and Trinidad. Seven were new and in this paper, we describe them, their development sites and the third stage larva and/or the puparium of all ten species. One new synonym is proposed, Copestylum pinkusi (Curran) [= Copestylum cinctiventre (Curran)]. Similarities and differences between these new and other Copestylum species, suggest they separate into two groups, referred to as the Vagum and Cinctiventre species groups. Features characterising these groups for both adult and early stages are assessed. Each species was also distinguished using adult and early stage characters. Within the Vagum group, adults were more disparate morphologically than the larval stage; this was reversed in the Cinctiventre group. Adult colour patterns are probably cryptic in function and for disguise. Vagum species have disruptive marks, while the Cinctiventre species have reflective colours. Biologically, the groups are almost distinguished by larval development sites. Vagum species use predominantly fruits and have a larval stage that is relatively generalised in form and habit. Cinctiventre species are confined to developing in flowers and the larva is more specialised. A key to both adult and early stages of all ten species is provided. PMID:26580811

Flower-specific jasmonate signaling regulates constitutive floral defenses in wild tobacco

PubMed Central

Li, Ran; Wang, Ming; Wang, Yang; Schuman, Meredith C.; Weinhold, Arne; Schäfer, Martin; Jiménez-Alemán, Guillermo H.; Barthel, Andrea; Baldwin, Ian T.

2017-01-01

Optimal defense (OD) theory predicts that within a plant, tissues are defended in proportion to their fitness value and risk of predation. The fitness value of leaves varies greatly and leaves are protected by jasmonate (JA)-inducible defenses. Flowers are vehicles of Darwinian fitness in flowering plants and are attacked by herbivores and pathogens, but how they are defended is rarely investigated. We used Nicotiana attenuata, an ecological model plant with well-characterized herbivore interactions to characterize defense responses in flowers. Early floral stages constitutively accumulate greater amounts of two well-characterized defensive compounds, the volatile (E)-α-bergamotene and trypsin proteinase inhibitors (TPIs), which are also found in herbivore-induced leaves. Plants rendered deficient in JA biosynthesis or perception by RNA interference had significantly attenuated floral accumulations of defensive compounds known to be regulated by JA in leaves. By RNA-seq, we found a JAZ gene, NaJAZi, specifically expressed in early-stage floral tissues. Gene silencing revealed that NaJAZi functions as a flower-specific jasmonate repressor that regulates JAs, (E)-α-bergamotene, TPIs, and a defensin. Flowers silenced in NaJAZi are more resistant to tobacco budworm attack, a florivore. When the defensin was ectopically expressed in leaves, performance of Manduca sexta larvae, a folivore, decreased. NaJAZi physically interacts with a newly identified NINJA-like protein, but not the canonical NINJA. This NINJA-like recruits the corepressor TOPLESS that contributes to the suppressive function of NaJAZi on floral defenses. This study uncovers the defensive function of JA signaling in flowers, which includes components that tailor JA signaling to provide flower-specific defense. PMID:28784761

Patterning of inflorescences and flowers by the F-Box protein DOUBLE TOP and the LEAFY homolog ABERRANT LEAF AND FLOWER of petunia.

PubMed

Souer, Erik; Rebocho, Alexandra B; Bliek, Mattijs; Kusters, Elske; de Bruin, Robert A M; Koes, Ronald

2008-08-01

Angiosperms display a wide variety of inflorescence architectures differing in the positions where flowers or branches arise. The expression of floral meristem identity (FMI) genes determines when and where flowers are formed. In Arabidopsis thaliana, this is regulated via transcription of LEAFY (LFY), which encodes a transcription factor that promotes FMI. We found that this is regulated in petunia (Petunia hybrida) via transcription of a distinct gene, DOUBLE TOP (DOT), a homolog of UNUSUAL FLORAL ORGANS (UFO) from Arabidopsis. Mutation of DOT or its tomato (Solanum lycopersicum) homolog ANANTHA abolishes FMI. Ubiquitous expression of DOT or UFO in petunia causes very early flowering and transforms the inflorescence into a solitary flower and leaves into petals. Ectopic expression of DOT or UFO together with LFY or its homolog ABERRANT LEAF AND FLOWER (ALF) in petunia seedlings activates genes required for identity or outgrowth of organ primordia. DOT interacts physically with ALF, suggesting that it activates ALF by a posttranslational mechanism. Our findings suggest a wider role than previously thought for DOT and UFO in the patterning of flowers and indicate that the different roles of LFY and UFO homologs in the spatiotemporal control of floral identity in distinct species result from their divergent expression patterns.

A Regulatory Network for Coordinated Flower Maturation

PubMed Central

Ploense, Sara E.; Wu, Miin-Feng; Yadav, Vandana; Tholl, Dorothea; Chételat, Aurore; Haupt, Ina; Kennerley, Brian J.; Hodgens, Charles; Farmer, Edward E.; Nagpal, Punita; Reed, Jason W.

2012-01-01

For self-pollinating plants to reproduce, male and female organ development must be coordinated as flowers mature. The Arabidopsis transcription factors AUXIN RESPONSE FACTOR 6 (ARF6) and ARF8 regulate this complex process by promoting petal expansion, stamen filament elongation, anther dehiscence, and gynoecium maturation, thereby ensuring that pollen released from the anthers is deposited on the stigma of a receptive gynoecium. ARF6 and ARF8 induce jasmonate production, which in turn triggers expression of MYB21 and MYB24, encoding R2R3 MYB transcription factors that promote petal and stamen growth. To understand the dynamics of this flower maturation regulatory network, we have characterized morphological, chemical, and global gene expression phenotypes of arf, myb, and jasmonate pathway mutant flowers. We found that MYB21 and MYB24 promoted not only petal and stamen development but also gynoecium growth. As well as regulating reproductive competence, both the ARF and MYB factors promoted nectary development or function and volatile sesquiterpene production, which may attract insect pollinators and/or repel pathogens. Mutants lacking jasmonate synthesis or response had decreased MYB21 expression and stamen and petal growth at the stage when flowers normally open, but had increased MYB21 expression in petals of older flowers, resulting in renewed and persistent petal expansion at later stages. Both auxin response and jasmonate synthesis promoted positive feedbacks that may ensure rapid petal and stamen growth as flowers open. MYB21 also fed back negatively on expression of jasmonate biosynthesis pathway genes to decrease flower jasmonate level, which correlated with termination of growth after flowers have opened. These dynamic feedbacks may promote timely, coordinated, and transient growth of flower organs. PMID:22346763

Phytoplasma effector SAP54 induces indeterminate leaf-like flower development in Arabidopsis plants.

PubMed

MacLean, Allyson M; Sugio, Akiko; Makarova, Olga V; Findlay, Kim C; Grieve, Victoria M; Tóth, Réka; Nicolaisen, Mogens; Hogenhout, Saskia A

2011-10-01

Phytoplasmas are insect-transmitted bacterial plant pathogens that cause considerable damage to a diverse range of agricultural crops globally. Symptoms induced in infected plants suggest that these phytopathogens may modulate developmental processes within the plant host. We report herein that Aster Yellows phytoplasma strain Witches' Broom (AY-WB) readily infects the model plant Arabidopsis (Arabidopsis thaliana) ecotype Columbia, inducing symptoms that are characteristic of phytoplasma infection, such as the production of green leaf-like flowers (virescence and phyllody) and increased formation of stems and branches (witches' broom). We found that the majority of genes encoding secreted AY-WB proteins (SAPs), which are candidate effector proteins, are expressed in Arabidopsis and the AY-WB insect vector Macrosteles quadrilineatus (Hemiptera; Cicadellidae). To identify which of these effector proteins induce symptoms of phyllody and virescence, we individually expressed the effector genes in Arabidopsis. From this screen, we have identified a novel AY-WB effector protein, SAP54, that alters floral development, resulting in the production of leaf-like flowers that are similar to those produced by plants infected with this phytoplasma. This study offers novel insight into the effector profile of an insect-transmitted plant pathogen and reports to our knowledge the first example of a microbial pathogen effector protein that targets flower development in a host.

Genetic interactions of the unfinished flower development (ufd) mutant support a significant role of the tomato UFD gene in regulating floral organogenesis.

PubMed

Poyatos-Pertíñez, Sandra; Quinet, Muriel; Ortíz-Atienza, Ana; Bretones, Sandra; Yuste-Lisbona, Fernando J; Lozano, Rafael

2016-09-01

Genetic interactions of UFD gene support its specific function during reproductive development of tomato; in this process, UFD could play a pivotal role between inflorescence architecture and flower initiation genes. Tomato (Solanum lycopersicum L.) is a major vegetable crop that also constitutes a model species for the study of plant developmental processes. To gain insight into the control of flowering and floral development, a novel tomato mutant, unfinished flower development (ufd), whose inflorescence and flowers were unable to complete their normal development was characterized using double mutant and gene expression analyses. Genetic interactions of ufd with mutations affecting inflorescence fate (uniflora, jointless and single flower truss) were additive and resulted in double mutants displaying the inflorescence structure of the non-ufd parental mutant and the flower phenotype of the ufd mutant. In addition, ufd mutation promotes an earlier inflorescence meristem termination. Taken together, both results indicated that UFD is not involved in the maintenance of inflorescence meristem identity, although it could participate in the regulatory system that modulates the rate of meristem maturation. Regarding the floral meristem identity, the falsiflora mutation was epistatic to the ufd mutation even though FALSIFLORA was upregulated in ufd inflorescences. In terms of floral organ identity, the ufd mutation was epistatic to macrocalyx, and MACROCALYX expression was differently regulated depending on the inflorescence developmental stage. These results suggest that the UFD gene may play a pivotal role between the genes required for flowering initiation and inflorescence development (such as UNIFLORA, FALSIFLORA, JOINTLESS and SINGLE FLOWER TRUSS) and those required for further floral organ development such as the floral organ identity genes.

MAEWEST expression in flower development of two petunia species.

PubMed

Segatto, Ana Lúcia A; Turchetto-Zolet, Andreia Carina; Aizza, Lilian Cristina B; Monte-Bello, Carolina C; Dornelas, Marcelo C; Margis, Rogerio; Freitas, Loreta B

2013-07-03

Changes in flower morphology may influence the frequency and specificity of animal visitors. In Petunia (Solanaceae), adaptation to different pollinators is one of the factors leading to species diversification within the genus. This study provides evidence that differential expression patterns of MAWEWEST (MAW) homologs in different Petunia species may be associated with adaptive changes in floral morphology. The Petunia × hybrida MAW gene belongs to the WOX (WUSCHEL-related homeobox) transcription factor family and has been identified as a controller of petal fusion during corolla formation. We analyzed the expression patterns of P. inflata and P. axillaris MAW orthologs (PiMAW and PaMAW, respectively) by reverse transcriptase polymerase chain reaction (RT-PCR), reverse transcription-quantitative PCR (qRT-PCR) and in situ hybridization in different tissues and different developmental stages of flowers in both species. The spatial expression patterns of PiMAW and PaMAW were similar in P. inflata and P. axillaris. Nevertheless, PaMAW expression level in P. axillaris was higher during the late bud development stage as compared to PiMAW in P. inflata. This work represents an expansion of petunia developmental research to wild accessions.

MAEWEST Expression in Flower Development of Two Petunia Species

PubMed Central

Segatto, Ana Lúcia A.; Turchetto-Zolet, Andreia Carina; Aizza, Lilian Cristina B.; Monte-Bello, Carolina C.; Dornelas, Marcelo C.; Margis, Rogerio; Freitas, Loreta B.

2013-01-01

Changes in flower morphology may influence the frequency and specificity of animal visitors. In Petunia (Solanaceae), adaptation to different pollinators is one of the factors leading to species diversification within the genus. This study provides evidence that differential expression patterns of MAWEWEST (MAW) homologs in different Petunia species may be associated with adaptive changes in floral morphology. The Petunia × hybrida MAW gene belongs to the WOX (WUSCHEL-related homeobox) transcription factor family and has been identified as a controller of petal fusion during corolla formation. We analyzed the expression patterns of P. inflata and P. axillaris MAW orthologs (PiMAW and PaMAW, respectively) by reverse transcriptase polymerase chain reaction (RT-PCR), reverse transcription–quantitative PCR (qRT-PCR) and in situ hybridization in different tissues and different developmental stages of flowers in both species. The spatial expression patterns of PiMAW and PaMAW were similar in P. inflata and P. axillaris. Nevertheless, PaMAW expression level in P. axillaris was higher during the late bud development stage as compared to PiMAW in P. inflata. This work represents an expansion of petunia developmental research to wild accessions. PMID:23823801

Floral Development of Berberidopsis corallina: a Crucial Link in the Evolution of Flowers in the Core Eudicots

PubMed Central

RONSE DE CRAENE, LOUIS P.

2004-01-01

• Background and Aims On the basis of molecular evidence Berberidopsidaceae have been linked with Aextoxicaceae in an order Berberidopsidales at the base of the core Eudicots. The floral development of Berberidopsis is central to the understanding of the evolution of floral configurations at the transition of the basal Eudicots to the core Eudicots. It lies at the transition of trimerous or dimerous, simplified apetalous forms into pentamerous, petaliferous flowers. • Methods The floral ontogeny of Berberidopsis was studied with a scanning electron microscope. • Key Results Flowers are grouped in terminal racemes with variable development. The relationship between the number of tepals, stamens and carpels is more or less fixed and floral initiation follows a strict 2/5 phyllotaxis. Two bracteoles, 12 tepals, eight stamens and three carpels are initiated in a regular sequence. The number of stamens can be increased by a doubling of stamen positions. • Conclusions The floral ontogeny of Berberidopsis provides support for the shift in floral bauplan from the basal Eudicots to the core Eudicots as a transition of a spiral flower with a 2/5 phyllotaxis to pentamerous flowers with two perianth whorls, two stamen whorls and a single carpel whorl. The differentiation of sepals and petals from bracteotepals is discussed and a comparison is made with other Eudicots with a similar configuration and development. Depending on the resolution of the relationships among the basalmost core Eudicots it is suggested that Berberidopsis either represents a critical stage in the evolution of pentamerous flowers of major clades of Eudicots, or has a floral prototype that may be at the base of evolution of flowers of other core Eudicots. The distribution of a floral Bauplan in other clades of Eudicots similar to Berberidopsidales is discussed. PMID:15451722

Pea VEGETATIVE2 Is an FD Homolog That Is Essential for Flowering and Compound Inflorescence Development

PubMed Central

Sussmilch, Frances C.; Berbel, Ana; Hecht, Valérie; Vander Schoor, Jacqueline K.; Ferrándiz, Cristina; Madueño, Francisco; Weller, James L.

2015-01-01

As knowledge of the gene networks regulating inflorescence development in Arabidopsis thaliana improves, the current challenge is to characterize this system in different groups of crop species with different inflorescence architecture. Pea (Pisum sativum) has served as a model for development of the compound raceme, characteristic of many legume species, and in this study, we characterize the pea VEGETATIVE2 (VEG2) locus, showing that it is critical for regulation of flowering and inflorescence development and identifying it as a homolog of the bZIP transcription factor FD. Through detailed phenotypic characterizations of veg2 mutants, expression analyses, and the use of protein-protein interaction assays, we find that VEG2 has important roles during each stage of development of the pea compound inflorescence. Our results suggest that VEG2 acts in conjunction with multiple FLOWERING LOCUS T (FT) proteins to regulate expression of downstream target genes, including TERMINAL FLOWER1, LEAFY, and MADS box homologs, and to facilitate cross-regulation within the FT gene family. These findings further extend our understanding of the mechanisms underlying compound inflorescence development in pea and may have wider implications for future manipulation of inflorescence architecture in related legume crop species. PMID:25804541

Molecular cloning and functional analysis of the FLOWERING LOCUS T (FT) homolog GhFT1 from Gossypium hirsutum.

PubMed

Guo, Danli; Li, Chao; Dong, Rui; Li, Xiaobo; Xiao, Xiangwen; Huang, Xianzhong

2015-06-01

FLOWERING LOCUS T (FT) encodes a member of the phosphatidylethanolamine-binding protein (PEBP) family that functions as the mobile floral signal, playing an important role in regulating the floral transition in angiosperms. We isolated an FT-homolog (GhFT1) from Gossypium hirsutum L. cultivar, Xinluzao 33 GhFT1 was predominantly expressed in stamens and sepals, and had a relatively higher expression level during the initiation stage of fiber development. GhFT1 mRNA displayed diurnal oscillations in both long-day and short-day condition, suggesting that the expression of this gene may be under the control of the circadian clock. Subcellular analysis revealed that GhFT1 protein located in the cytoplasm and nucleus. Ectopic expression of GhFT1 in transgenic arabidopsis plants resulted in early flowering compared with wild-type plants. In addition, ectopic expression of GhFT1 in arabidopsis ft-10 mutants partially rescued the extremely late flowering phenotype. Finally, several flowering related genes functioning downstream of AtFT were highly upregulated in the 35S::GhFT1 transgenic arabidopsis plants. In summary, GhFT1 is an FT-homologous gene in cotton that regulates flower transition similar to its orthologs in other plant species and thus it may be a candidate target for promoting early maturation in cotton breeding. © 2014 Institute of Botany, Chinese Academy of Sciences.

Interactions of OsMADS1 with Floral Homeotic Genes in Rice Flower Development.

PubMed

Hu, Yun; Liang, Wanqi; Yin, Changsong; Yang, Xuelian; Ping, Baozhe; Li, Anxue; Jia, Ru; Chen, Mingjiao; Luo, Zhijing; Cai, Qiang; Zhao, Xiangxiang; Zhang, Dabing; Yuan, Zheng

2015-09-01

During reproductive development, rice plants develop unique flower organs which determine the final grain yield. OsMADS1, one of SEPALLATA-like MADS-box genes, has been unraveled to play critical roles in rice floral organ identity specification and floral meristem determinacy. However, the molecular mechanisms underlying interactions of OsMADS1 with other floral homeotic genes in regulating flower development remains largely elusive. In this work, we studied the genetic interactions of OsMADS1 with B-, C-, and D-class genes along with physical interactions among their proteins. We show that the physical and genetic interactions between OsMADS1 and OsMADS3 are essential for floral meristem activity maintenance and organ identity specification; while OsMADS1 physically and genetically interacts with OsMADS58 in regulating floral meristem determinacy and suppressing spikelet meristem reversion. We provided important genetic evidence to support the neofunctionalization of two rice C-class genes (OsMADS3 and OsMADS58) during flower development. Gene expression profiling and quantitative RT-PCR analyses further revealed that OsMADS1 affects the expression of many genes involved in floral identity and hormone signaling, and chromatin immunoprecipitation (ChIP)-PCR assay further demonstrated that OsMADS17 is a direct target gene of OsMADS1. Taken together, these results reveal that OsMADS1 has diversified regulatory functions in specifying rice floral organ and meristem identity, probably through its genetic and physical interactions with different floral homeotic regulators. Copyright © 2015 The Author. Published by Elsevier Inc. All rights reserved.

Functional characterization of a putative glycine max ELF4 transgenic aradopsis and its role during flowering control

USDA-ARS?s Scientific Manuscript database

Flowering is an important trait in major crops like soybean due to its direct relation to grain production. The circadian clock mediates the perception of seasonal changes in day length and temperature to modulate flowering time. The circadian clock gene EARLY FLOWERING 4 (ELF4) was identified in Ar...

[Morphogenetic lability of reproductive structures in Ruppia maritima (Ruppiaceae, Alismatales): from two lateral flowers to a terminal flower].

PubMed

Lokk, I É; Sokolov, D D; Remizova, M V

2011-01-01

Flowers of Ruppia are normally arranged into an open two-flowered spike, but sometimes the two lateral flowers are congenitally united with each other and form a terminal flower-like structure. This developmental abnormality resembles those described in well-investigated mutants of model organisms of developmental genetics such as Arabidopsis Antirrhinum. A study of Ruppia allows investigating morphogenetic lability of this feature in natural populations. These data will be important for understanding evolutionary transitions between open and closed inflorescences. This paper presents first data on frequencies ofterminal flower-like structures in natural populations of Ruppia maritima and first observations of their development. Vascular supply of inflorescences with free and united flowers is compared for the first time. Strong differences in frequencies of occurrence of terminal flower-like structures among examined natural populations are revealed. Data on variation of organ numbers in flowers of plants from different populations allow hypothesizing that increased size of floral primordia is a factor that plays a role in their amalgamation into ajoint primordium of a terminal structure. Vascular system of inflorescences of R. maritima with united flowers is quite similar to the vascular system of a flower and nothing contradicts a hypothesis on terminal position ofthis structure. Transversally inserted stamens in inflorescences with united flowers are usually of inverted polarity. This appears to be the first documented example of an inversion of relative polarity of stamens and carpels in angiosperms.

Phytohormone and assimilate profiles in emasculated flowers of the black locust (Robinia pseudoacacia) during development.

PubMed

Sun, Peng; Yuan, Cunquan; Dai, Li; Xi, Yang; Li, Yunfei; Hu, Ruiyang; Sun, Yuhan; Xu, Zhaohe; Li, Yun

2013-09-01

Emasculation and bagging of flowers, which are widely used in the controlled pollination of monoclinous plants, may induce premature senescence, flower abscission and low fruit set. To determine the mechanism responsible for these phenomena, levels of abscisic acid (ABA), jasmonic acid (JA), indole-3-acetic acid (IAA), ethylene, soluble sugars, reducing sugars and free amino acids in black locust (Robinia pseudoacacia) flowers subjected to different treatments were quantified at different developmental stages. The phytohormones and assimilates were also quantified in untreated flowers to investigate the presence of discernible patterns. The levels of ethylene and ABA in emasculated and bagged (EB) flowers increased prematurely compared with those of untreated flowers, whereas the content of reducing sugars in EB flowers decreased compared with that of untreated flowers. These results indicated that the premature increase in ethylene and ABA synthesis, and the decrease in reducing sugars content, in EB flowers may cause flower abscission and result in low fruit set, which may be relevant for assimilate applications and future research on the regulation of controlled pollinations with exogenous phytohormones.

Genome-wide association mapping of flowering time and maturity dates in early mature soybean germplasm

USDA-ARS?s Scientific Manuscript database

Soybean (Glycine max L. Merr.) is a photoperiod-sensitive and short-day major crop grown worldwide. Days to flowering (DTF) and maturity (DTM) are two traits affecting soybean adaptability and yield. Some genes conditioning soybean flowering and maturity have been recently characterized. However, ...

Flowers in Their Variety.

ERIC Educational Resources Information Center

Flannery, Maura C.

2002-01-01

Describes the diversity of flowers with regard to the flower paintings of Pierre-Joseph Redoute, books about flowers, and research in genetic studies. Discusses gardening flowers and flowering strategies and criticizes the fact that biology education has moved steadily away from plants. (KHR)

Expression profiling of FLOWERING LOCUS T-like gene in alternate bearing 'Hass' avocado trees suggests a role for PaFT in avocado flower induction.

PubMed

Ziv, Dafna; Zviran, Tali; Zezak, Oshrat; Samach, Alon; Irihimovitch, Vered

2014-01-01

In many perennials, heavy fruit load on a shoot decreases the ability of the plant to undergo floral induction in the following spring, resulting in a pattern of crop production known as alternate bearing. Here, we studied the effects of fruit load on floral determination in 'Hass' avocado (Persea americana). De-fruiting experiments initially confirmed the negative effects of fruit load on return to flowering. Next, we isolated a FLOWERING LOCUS T-like gene, PaFT, hypothesized to act as a phloem-mobile florigen signal and examined its expression profile in shoot tissues of on (fully loaded) and off (fruit-lacking) trees. Expression analyses revealed a strong peak in PaFT transcript levels in leaves of off trees from the end of October through November, followed by a return to starting levels. Moreover and concomitant with inflorescence development, only off buds displayed up-regulation of the floral identity transcripts PaAP1 and PaLFY, with significant variation being detected from October and November, respectively. Furthermore, a parallel microscopic study of off apical buds revealed the presence of secondary inflorescence axis structures that only appeared towards the end of November. Finally, ectopic expression of PaFT in Arabidopsis resulted in early flowering transition. Together, our data suggests a link between increased PaFT expression observed during late autumn and avocado flower induction. Furthermore, our results also imply that, as in the case of other crop trees, fruit-load might affect flowering by repressing the expression of PaFT in the leaves. Possible mechanism(s) by which fruit crop might repress PaFT expression, are discussed.

Flower, fruit phenology and flower traits in Cordia boissieri (Boraginaceae) from northeastern Mexico.

PubMed

Martínez-Adriano, Cristian Adrian; Jurado, Enrique; Flores, Joel; González-Rodríguez, Humberto; Cuéllar-Rodríguez, Gerardo

2016-01-01

We characterized variations in Cordia boissieri flowers and established if these variations occur between plants or between flowering events. Flowering and fruiting was measured for 256 plants. A GLM test was used to determine the relationship between flowering and fruit set processes and rainfall. We performed measurements of floral traits to detect variations within the population and between flowering events. The position of the anthers with respect to the ovary was determined in 1,500 flowers. Three out of four flowering events of >80% C. boissieri plants occurred after rainfall events. Only one flowering event occurred in a drought. Most plants flowered at least twice a year. The overlapping of flowering and fruiting only occurred after rainfall. Anthesis lasted three-to-five days, and there were two flower morphs. Half of the plants had longistylus and half had brevistylus flowers. Anacahuita flower in our study had 1-4 styles; 2-9 stamens; 6.5-41.5 mm long corolla; sepals from 4.5-29.5 mm in length; a total length from 15.5-59 mm; a corolla diameter from 10.5-77 mm. The nectar guide had a diameter from 5-30.5 mm; 4-9 lobes; and 5 distinguishable nectar guide colors. The highest variation of phenotypic expression was observed between plants.

Using daily temperature to predict phenology trends in spring flowers

NASA Astrophysics Data System (ADS)

Kim, Jin-Hee; Kim, Soo-Ock; Kim, Dae-Jun; Moon, Kyung Hwan; Yun, Jin I.

2015-05-01

temperature rise in early spring immediately after dormancy release, likely brought forward the flowering date of cherry blossom. We derived a thermal time-based flowering model from this analysis and used it to predict the flowering dates of forsythia and cherry blossom in 2014. The root mean square error for the prediction was within 2 days from the observed flowering dates in both species, showing a feasibility of prediction under the changing climate.

Development and Application of a Two-Tier Diagnostic Test for High School Students' Understanding of Flowering Plant Growth and Development

ERIC Educational Resources Information Center

Lin, Sheau-Wen

2004-01-01

This study involved the development and application of a two-tier diagnostic test measuring students' understanding of flowering plant growth and development. The instrument development procedure had three general steps: defining the content boundaries of the test, collecting information on students' misconceptions, and instrument development.…

Overexpression of DOSOC1, an ortholog of Arabidopsis SOC1, promotes flowering in the orchid Dendrobium Chao Parya Smile.

PubMed

Ding, Lihua; Wang, Yanwen; Yu, Hao

2013-04-01

SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1 (SOC1) encodes a MADS-box protein that plays an essential role in integrating multiple flowering signals to regulate the transition from vegetative to reproductive development in the model plant Arabidopsis. Although SOC1-like genes have been isolated in various angiosperms, its orthologs in Orchidaceae, one of the largest families of flowering plants, are so far unknown. To investigate the regulatory mechanisms of flowering time control in orchids, we isolated a SOC1-like gene, DOSOC1, from Dendrobium Chao Praya Smile. DOSOC1 was highly expressed in reproductive organs, including inflorescence apices, pedicels, floral buds and open flowers. Its expression significantly increased in whole plantlets during the transition from vegetative to reproductive development, which usually occurred after 8 weeks of culture in Dendrobium Chao Praya Smile. In the shoot apex at the floral transitional stage, DOSOC1 was particularly expressed in emerging floral meristems. Overexpression of DOSOC1 in wild-type Arabidopsis plants resulted in early flowering, which was coupled with the up-regulation of two other flowering promoters, AGAMOUS-LIKE 24 and LEAFY. In addition, overexpression of DOSOC1 was able partially to complement the late-flowering phenotype of Arabidopsis soc1-2 loss-of-function mutants. Furthermore, we successfully created seven 35S:DOSOC1 transgenic Dendrobium orchid lines, which consistently exhibited earlier flowering than wild-type orchids. Our results suggest that SOC1-like genes play an evolutionarily conserved role in promoting flowering in the Orchidaceae family, and that DOSOC1 isolated from Dendrobium Chao Praya Smile could serve as an important target for genetic manipulation of flowering time in orchids.

'Who's who' in two different flower types of Calluna vulgaris (Ericaceae): morphological and molecular analyses of flower organ identity

PubMed Central

2009-01-01

Background The ornamental crop Calluna vulgaris is of increasing importance to the horticultural industry in the northern hemisphere due to a flower organ mutation: the flowers of the 'bud-flowering' phenotype remain closed i.e. as buds throughout the total flowering period and thereby maintain more colorful flowers for a longer period of time than the wild-type. This feature is accompanied and presumably caused by the complete lack of stamens. Descriptions of this botanical particularity are inconsistent and partially conflicting. In order to clarify basic questions of flower organ identity in general and stamen loss in detail, a study of the wild-type and the 'bud-flowering' flower type of C. vulgaris was initiated. Results Flowers were examined by macro- and microscopic techniques. Organ development was investigated comparatively in both the wild-type and the 'bud-flowering' type by histological analyses. Analysis of epidermal cell surface structure of vegetative tissues and perianth organs using scanning electron microscopy revealed that in wild-type flowers the outer whorls of colored organs may be identified as sepals, while the inner ones may be identified as petals. In the 'bud-flowering' type, two whorls of sepals are directly followed by the gynoecium. Both, petals and stamens, are completely missing in this flower type. The uppermost whorl of green leaves represents bracts in both flower types. In addition, two MADS-box genes (homologs of AP3/DEF and SEP1/2) were identified in C. vulgaris using RACE-PCR. Expression analysis by qRT-PCR was conducted for both genes in leaves, bracts, sepals and petals. These experiments revealed an expression pattern supporting the organ classification based on morphological characteristics. Conclusions Organ identity in both wild-type and 'bud-flowering' C. vulgaris was clarified using a combination of microscopic and molecular methods. Our results for bract, sepal and petal organ identity are supported by the 'ABCDE

Molecular mapping of QTL alleles of Brassica oleracea affecting days to flowering and photosensitivity in spring Brassica napus

PubMed Central

Bennett, Rick A.; Kebede, Berisso

2018-01-01

Earliness of flowering and maturity are important traits in spring Brassica napus canola–whether grown under long- or short-day condition. By use of a spring B. napus mapping population carrying the genome content of B. oleracea and testing this population under 10 to 18 h photoperiod and 18 to 20 0C (day) temperature conditions, we identified a major QTL on the chromosome C1 affecting flowering time without being influenced by photoperiod and temperature, and a major QTL on C9 affecting flowering time under a short photoperiod (10 h); in both cases, the QTL alleles reducing the number of days to flowering in B. napus were introgressed from the late flowering species B. oleracea. Additive effect of the C1 QTL allele at 14 to18 h photoperiod was 1.1 to 2.9 days; however, the same QTL allele exerted an additive effect of 6.2 days at 10 h photoperiod. Additive effect of the C9 QTL at 10 h photoperiod was 2.8 days. These two QTL also showed significant interaction in the control of flowering only under a short-day (10 h photoperiod) condition with an effect of 2.3 days. A few additional QTL were also detected on the chromosomes C2 and C8; however, none of these QTL could be detected under all photoperiod and temperature conditions. BLASTn search identified several putative flowering time genes on the chromosomes C1 and C9 and located the physical position of the QTL markers in the Brassica genome; however, only a few of these genes were found within the QTL region. Thus, the molecular markers and the genomic regions identified in this research could potentially be used in breeding for the development of early flowering photoinsensitive B. napus canola cultivars, as well as for identification of candidate genes involved in flowering time variation and photosensitivity. PMID:29320498

Molecular mapping of QTL alleles of Brassica oleracea affecting days to flowering and photosensitivity in spring Brassica napus.

PubMed

Rahman, Habibur; Bennett, Rick A; Kebede, Berisso

2018-01-01

Earliness of flowering and maturity are important traits in spring Brassica napus canola-whether grown under long- or short-day condition. By use of a spring B. napus mapping population carrying the genome content of B. oleracea and testing this population under 10 to 18 h photoperiod and 18 to 20 0C (day) temperature conditions, we identified a major QTL on the chromosome C1 affecting flowering time without being influenced by photoperiod and temperature, and a major QTL on C9 affecting flowering time under a short photoperiod (10 h); in both cases, the QTL alleles reducing the number of days to flowering in B. napus were introgressed from the late flowering species B. oleracea. Additive effect of the C1 QTL allele at 14 to18 h photoperiod was 1.1 to 2.9 days; however, the same QTL allele exerted an additive effect of 6.2 days at 10 h photoperiod. Additive effect of the C9 QTL at 10 h photoperiod was 2.8 days. These two QTL also showed significant interaction in the control of flowering only under a short-day (10 h photoperiod) condition with an effect of 2.3 days. A few additional QTL were also detected on the chromosomes C2 and C8; however, none of these QTL could be detected under all photoperiod and temperature conditions. BLASTn search identified several putative flowering time genes on the chromosomes C1 and C9 and located the physical position of the QTL markers in the Brassica genome; however, only a few of these genes were found within the QTL region. Thus, the molecular markers and the genomic regions identified in this research could potentially be used in breeding for the development of early flowering photoinsensitive B. napus canola cultivars, as well as for identification of candidate genes involved in flowering time variation and photosensitivity.

Pea VEGETATIVE2 Is an FD Homolog That Is Essential for Flowering and Compound Inflorescence Development.

PubMed

Sussmilch, Frances C; Berbel, Ana; Hecht, Valérie; Vander Schoor, Jacqueline K; Ferrándiz, Cristina; Madueño, Francisco; Weller, James L

2015-04-01

As knowledge of the gene networks regulating inflorescence development in Arabidopsis thaliana improves, the current challenge is to characterize this system in different groups of crop species with different inflorescence architecture. Pea (Pisum sativum) has served as a model for development of the compound raceme, characteristic of many legume species, and in this study, we characterize the pea VEGETATIVE2 (VEG2) locus, showing that it is critical for regulation of flowering and inflorescence development and identifying it as a homolog of the bZIP transcription factor FD. Through detailed phenotypic characterizations of veg2 mutants, expression analyses, and the use of protein-protein interaction assays, we find that VEG2 has important roles during each stage of development of the pea compound inflorescence. Our results suggest that VEG2 acts in conjunction with multiple FLOWERING LOCUS T (FT) proteins to regulate expression of downstream target genes, including TERMINAL FLOWER1, LEAFY, and MADS box homologs, and to facilitate cross-regulation within the FT gene family. These findings further extend our understanding of the mechanisms underlying compound inflorescence development in pea and may have wider implications for future manipulation of inflorescence architecture in related legume crop species. © 2015 American Society of Plant Biologists. All rights reserved.

Flower, fruit phenology and flower traits in Cordia boissieri (Boraginaceae) from northeastern Mexico

PubMed Central

Martínez-Adriano, Cristian Adrian; Flores, Joel; González-Rodríguez, Humberto; Cuéllar-Rodríguez, Gerardo

2016-01-01

We characterized variations in Cordia boissieri flowers and established if these variations occur between plants or between flowering events. Flowering and fruiting was measured for 256 plants. A GLM test was used to determine the relationship between flowering and fruit set processes and rainfall. We performed measurements of floral traits to detect variations within the population and between flowering events. The position of the anthers with respect to the ovary was determined in 1,500 flowers. Three out of four flowering events of >80% C. boissieri plants occurred after rainfall events. Only one flowering event occurred in a drought. Most plants flowered at least twice a year. The overlapping of flowering and fruiting only occurred after rainfall. Anthesis lasted three-to-five days, and there were two flower morphs. Half of the plants had longistylus and half had brevistylus flowers. Anacahuita flower in our study had 1–4 styles; 2–9 stamens; 6.5–41.5 mm long corolla; sepals from 4.5–29.5 mm in length; a total length from 15.5–59 mm; a corolla diameter from 10.5–77 mm. The nectar guide had a diameter from 5–30.5 mm; 4–9 lobes; and 5 distinguishable nectar guide colors. The highest variation of phenotypic expression was observed between plants. PMID:27231656

Molecular aspects of flower senescence and strategies to improve flower longevity

PubMed Central

Shibuya, Kenichi

2018-01-01

Flower longevity is one of the most important traits for ornamental plants. Ethylene plays a crucial role in flower senescence in some plant species. In several species that show ethylene-dependent flower senescence, genetic modification targeting genes for ethylene biosynthesis or signaling has improved flower longevity. Although little is known about regulatory mechanisms of petal senescence in flowers that show ethylene-independent senescence, a recent study of Japanese morning glory revealed that a NAC transcription factor, EPHEMERAL1 (EPH1), is a key regulator in ethylene-independent petal senescence. EPH1 is induced in an age-dependent manner irrespective of ethylene signal, and suppression of EPH1 expression dramatically delays petal senescence. In ethylene-dependent petal senescence, comprehensive transcriptome analyses revealed the involvement of transcription factors, a basic helix-loop-helix protein and a homeodomain-leucine zipper protein, in the transcriptional regulation of the ethylene biosynthesis enzymes. This review summarizes molecular aspects of flower senescence and discusses strategies to improve flower longevity by molecular breeding. PMID:29681752

Anthocyanin Profiles in Flowers of Grape Hyacinth.

PubMed

Lou, Qian; Wang, Lin; Liu, Hongli; Liu, Yali

2017-04-26

Grape hyacinth ( Muscari spp.) is a popular ornamental bulbous perennial famous for its blue flowers. To understand the chemical basis of the rich blue colors in this plant, anthocyanin profiles of six blue flowering grape hyacinths as well as one pink and one white cultivar were determined using high-performance liquid chromatography and mass spectrometry. Along with two known compounds, eight putative anthocyanins were identified in the tepals of grape hyacinth for the first time. The accumulation and distribution of anthocyanins in the plant showed significant cultivar and flower development specificity. Violet-blue flowers mainly contained simple delphinidin-type anthocyanins bearing one or two methyl-groups but no acyl groups, whereas white and pink flowers synthesised more complex pelargonidin/cyanidin-derivatives with acyl-moieties but no methyl-groups. The results partially reveal why solid blue, orange or red flowers are rare in this plant in nature. In addition, pelargonidin-type anthocyanins were found for the first time in the genus, bringing more opportunities in terms of breeding of flower color in grape hyacinth.

Vascular development of the grapevine (Vitis vinifera L.) inflorescence rachis in response to flower number, plant growth regulators and defoliation.

PubMed

Gourieroux, Aude M; Holzapfel, Bruno P; McCully, Margaret E; Scollary, Geoffrey R; Rogiers, Suzy Y

2017-09-01

The grapevine inflorescence is a determinate panicle and as buds emerge, shoot, flower and rachis development occur simultaneously. The growth and architecture of the rachis is determined by genetic and environmental factors but here we examined the role of flower and leaf number as well as hormones on its elongation and vascular development. The consequences of rachis morphology and vascular area on berry size and composition were also assessed. One week prior to anthesis, Merlot and Cabernet Sauvignon field vines were exposed to manual flower removal, exogenous plant growth regulators or pre-bloom leaf removal. Manual removal of half the flowers along the vertical axis of the inflorescence resulted in a shorter rachis in both cultivars. Conversely, inflorescences treated with gibberellic acid (GA 3 ) and the synthetic cytokinin, 6-benzylaminopurine (BAP) resulted in a longer rachis while pre-bloom removal of all leaves on the inflorescence-bearing shoot did not alter rachis length relative to untreated inflorescences. Across the treatments, the cross-sectional areas of the conducting xylem and phloem in the rachis were positively correlated to rachis girth, flower number at anthesis, bunch berry number, bunch berry fresh mass and bunch sugar content at harvest. Conversely, average berry size and sugar content were not linked to rachis vascular area. These data indicate that the morphological and vascular development of the rachis was more responsive to flower number and plant growth regulators than to leaf removal.

Expression Profiling of FLOWERING LOCUS T-Like Gene in Alternate Bearing ‘Hass' Avocado Trees Suggests a Role for PaFT in Avocado Flower Induction

PubMed Central

Ziv, Dafna; Zviran, Tali; Zezak, Oshrat; Samach, Alon; Irihimovitch, Vered

2014-01-01

In many perennials, heavy fruit load on a shoot decreases the ability of the plant to undergo floral induction in the following spring, resulting in a pattern of crop production known as alternate bearing. Here, we studied the effects of fruit load on floral determination in ‘Hass' avocado (Persea americana). De-fruiting experiments initially confirmed the negative effects of fruit load on return to flowering. Next, we isolated a FLOWERING LOCUS T-like gene, PaFT, hypothesized to act as a phloem-mobile florigen signal and examined its expression profile in shoot tissues of on (fully loaded) and off (fruit-lacking) trees. Expression analyses revealed a strong peak in PaFT transcript levels in leaves of off trees from the end of October through November, followed by a return to starting levels. Moreover and concomitant with inflorescence development, only off buds displayed up-regulation of the floral identity transcripts PaAP1 and PaLFY, with significant variation being detected from October and November, respectively. Furthermore, a parallel microscopic study of off apical buds revealed the presence of secondary inflorescence axis structures that only appeared towards the end of November. Finally, ectopic expression of PaFT in Arabidopsis resulted in early flowering transition. Together, our data suggests a link between increased PaFT expression observed during late autumn and avocado flower induction. Furthermore, our results also imply that, as in the case of other crop trees, fruit-load might affect flowering by repressing the expression of PaFT in the leaves. Possible mechanism(s) by which fruit crop might repress PaFT expression, are discussed. PMID:25330324

Hydraulic conductance and the maintenance of water balance in flowers.

PubMed

Roddy, Adam B; Brodersen, Craig R; Dawson, Todd E

2016-10-01

Flowers face desiccating conditions, yet little is known about their ability to transport water. We quantified variability in floral hydraulic conductance (Kflower ) for 20 species from 10 families and related it to traits hypothesized to be associated with liquid and vapour phase water transport. Basal angiosperm flowers had trait values associated with higher water and carbon costs than monocot and eudicot flowers. Kflower was coordinated with water supply (vein length per area, VLA) and loss (minimum epidermal conductance, gmin ) traits among the magnoliids, but was insensitive to variation in these traits among the monocots and eudicots. Phylogenetic independent contrast (PIC) correlations revealed that few traits had undergone coordinated evolution. However, VLA and the desiccation time (Tdes ), the quotient of water content and gmin , had significant trait and PIC correlations. The near absence of stomata from monocot and eudicot flowers may have been critical in minimizing water loss rates among these clades. Early divergent, basal angiosperm flowers maintain higher Kflower because of traits associated with high rates water loss and water supply, while monocot and eudicot flowers employ a more conservative strategy of limiting water loss and may rely on stored water to maintain turgor and delay desiccation. © 2016 John Wiley & Sons Ltd.

Trithorax Group Protein Oryza sativa Trithorax1 Controls Flowering Time in Rice via Interaction with Early heading date31[W][OPEN

PubMed Central

Choi, Sang Chul; Lee, Shinyoung; Kim, Sung-Ryul; Lee, Yang-Seok; Liu, Chunyan; Cao, Xiaofeng; An, Gynheung

2014-01-01

Trithorax group proteins are chromatin-remodeling factors that activate target gene expression by antagonistically functioning against the Polycomb group. In Arabidopsis (Arabidopsis thaliana), Arabidopsis Trithorax protein1 (ATX1) regulates flowering time and floral organ identity. Here, we observed that suppression of Oryza sativa Trithorax1 (OsTrx1), an ortholog of ATX1, delayed flowering time in rice (Oryza sativa). Because the delay occurred only under long-day conditions, we evaluated the flowering signal pathways that specifically function under long-day conditions. Among them, the OsMADS50 and Heading date1 pathways were not affected by the mutation. However, the Grain number, plant height, and heading date7 (Ghd7) pathway was altered in ostrx1. Transcript levels of OsGI, phytochrome genes, and Early heading date3 (Ehd3), which function upstream of Ghd7, were unchanged in the mutant. Because Trx group proteins form a complex with other proteins to modify the chromatin structure of target genes, we investigated whether OsTrx1 interacts with a previously identified protein that functions upstream of Ghd7. We demonstrated that the plant homeodomain motif of OsTrx1 binds to native histone H3 from the calf thymus and that OsTrx1 binds to Ehd3 through the region between the plant homeodomain and SET domains. Finally, we showed that the SET domain at the C-terminal end of OsTrx1 has histone H3 methyltransferase activity when incubated with oligonucleosomes. Our results suggest that OsTrx1 plays an important role in regulating flowering time in rice by modulating chromatin structure. PMID:24420930

The Arabidopsis E3 Ubiquitin Ligase HOS1 Negatively Regulates CONSTANS Abundance in the Photoperiodic Control of Flowering[W

PubMed Central

Lazaro, Ana; Valverde, Federico; Piñeiro, Manuel; Jarillo, Jose A.

2012-01-01

The Arabidopsis thaliana early in short days6 (esd6) mutant was isolated in a screen for mutations that accelerate flowering time. Among other developmental alterations, esd6 displays early flowering in both long- and short-day conditions. Fine mapping of the mutation showed that the esd6 phenotype is caused by a lesion in the HIGH EXPRESSION OF OSMOTICALLY RESPONSIVE GENES1 (HOS1) locus, which encodes a RING finger–containing E3 ubiquitin ligase. The esd6/hos1 mutation causes decreased FLOWERING LOCUS C expression and requires CONSTANS (CO) protein for its early flowering phenotype under long days. Moreover, CO and HOS1 physically interact in vitro and in planta, and HOS1 regulates CO abundance, particularly during the daylight period. Accordingly, hos1 causes a shift in the regular long-day pattern of expression of FLOWERING LOCUS T (FT) transcript, starting to rise 4 h after dawn in the mutant. In addition, HOS1 interacts synergistically with CONSTITUTIVE PHOTOMORPHOGENIC1, another regulator of CO protein stability, in the regulation of flowering time. Taken together, these results indicate that HOS1 is involved in the control of CO abundance, ensuring that CO activation of FT occurs only when the light period reaches a certain length and preventing precocious flowering in Arabidopsis. PMID:22408073

Flower thermoregulation facilitates fertilization in Asian sacred lotus.

PubMed

Li, Jiao-Kun; Huang, Shuang-Quan

2009-05-01

The thermoregulatory flower of the Asian sacred lotus (Nelumbo nucifera) can maintain a relatively stable temperature despite great variations in ambient temperature during anthesis. The thermoregulation has been hypothesized to offer a direct energy reward for pollinators in lotus flowers. This study aims to examine whether the stable temperature maintained in the floral chamber influences the fertilization process and seed development. An artificial refrigeration instrument was employed to cool flowers during the fertilization process and post-fertilization period in an experimental population. The effect of temperature on post-pollination events was also examined by removing petals in two field populations. Treatments with low floral temperature did not reduce stigma receptivity or pollen viability in undehisced anthers. Low temperature during the fertilization period significantly decreased seed set per flower but low temperature during the phase of seed development had no effect, suggesting that temperature regulation by lotus flowers facilitated fertilization success. Hand-pollination treatments in two field populations indicated that seed set of flowers with petals removed was lower than that of intact flowers in north China, where ambient temperatures are low, but not in south China, confirming that reducing the temperature of carpels did influence post-pollination events. The experiments suggest that floral thermoregulation in lotus could enhance female reproductive success by facilitating fertilization.

Low flower-size variation in bilaterally symmetrical flowers: Support for the pollination precision hypothesis.

PubMed

Nikkeshi, Aoi; Kurimoto, Daiki; Ushimaru, Atushi

2015-12-01

The evolutionary shift from radial to bilateral symmetry in flowers is generally associated with the evolution of low flower-size variation. This phenomenon supports the hypothesis that the lower size variation in bilateral flowers can be attributed to low pollinator diversity. In this study, we propose two other hypotheses to explain low flower-size variation in bilateral symmetrical flowers. To test the three hypotheses, we examined the relative importance of pollinator diversity, composition, and bilateral symmetry itself as selective forces on low flower-size variation. We examined pollinator diversity and composition and flower-size variation for 36 species in a seminatural ecosystem with high bee richness and frequent lepidopteran visitation. Bilateral flowers were more frequently visited than radial flowers by larger bees, but functional-group diversity of the pollinators did not differ between symmetry types. Although bilateral flowers had significantly lower flower-size variation than radial flowers, flower-size variation did not vary with pollinator diversity and composition but was instead related to bilateral symmetry. Our results suggest that the lower size variation in bilateral flowers might have evolved under selection favoring the control of pollinator behavior on flowers to enhance the accurate placement of pollen on the body of the pollinator, independent of pollinator type. Because of the limited research on this issue, future work should be conducted in various types of plant-pollinator communities worldwide to further clarify the issue. © 2015 Botanical Society of America.

Understanding the role of floral development in the evolution of angiosperm flowers: clarifications from a historical and physico-dynamic perspective.

PubMed

Ronse De Craene, Louis

2018-05-01

Flower morphology results from the interaction of an established genetic program, the influence of external forces induced by pollination systems, and physical forces acting before, during and after initiation. Floral ontogeny, as the process of development from a meristem to a fully developed flower, can be approached either from a historical perspective, as a "recapitulation of the phylogeny" mainly explained as a process of genetic mutations through time, or from a physico-dynamic perspective, where time, spatial pressures, and growth processes are determining factors in creating the floral morphospace. The first (historical) perspective clarifies how flower morphology is the result of development over time, where evolutionary changes are only possible using building blocks that are available at a certain stage in the developmental history. Flowers are regulated by genetically determined constraints and development clarifies specific transitions between different floral morphs. These constraints are the result of inherent mutations or are induced by the interaction of flowers with pollinators. The second (physico-dynamic) perspective explains how changes in the physical environment of apical meristems create shifts in ontogeny and this is reflected in the morphospace of flowers. Changes in morphology are mainly induced by shifts in space, caused by the time of initiation (heterochrony), pressure of organs, and alterations of the size of the floral meristem, and these operate independently or in parallel with genetic factors. A number of examples demonstrate this interaction and its importance in the establishment of different floral forms. Both perspectives are complementary and should be considered in the understanding of factors regulating floral development. It is suggested that floral evolution is the result of alternating bursts of physical constraints and genetic stabilization processes following each other in succession. Future research needs to combine

The homeodomain transcription factor TaHDZipI-2 from wheat regulates frost tolerance, flowering time and spike development in transgenic barley.

PubMed

Kovalchuk, Nataliya; Chew, William; Sornaraj, Pradeep; Borisjuk, Nikolai; Yang, Nannan; Singh, Rohan; Bazanova, Natalia; Shavrukov, Yuri; Guendel, Andre; Munz, Eberhard; Borisjuk, Ljudmilla; Langridge, Peter; Hrmova, Maria; Lopato, Sergiy

2016-07-01

Homeodomain leucine zipper class I (HD-Zip I) transcription factors (TFs) play key roles in the regulation of plant growth and development under stresses. Functions of the TaHDZipI-2 gene isolated from the endosperm of developing wheat grain were revealed. Molecular characterization of TaHDZipI-2 protein included studies of its dimerisation, protein-DNA interactions and gene activation properties using pull-down assays, in-yeast methods and transient expression assays in wheat cells. The analysis of TaHDZipI-2 gene functions was performed using transgenic barley plants. It included comparison of developmental phenotypes, yield components, grain quality, frost tolerance and the levels of expression of potential target genes in transgenic and control plants. Transgenic TaHDZipI-2 lines showed characteristic phenotypic features that included reduced growth rates, reduced biomass, early flowering, light-coloured leaves and narrowly elongated spikes. Transgenic lines produced 25-40% more seeds per spike than control plants, but with 50-60% smaller grain size. In vivo lipid imaging exposed changes in the distribution of lipids between the embryo and endosperm in transgenic seeds. Transgenic lines were significantly more tolerant to frost than control plants. Our data suggest the role of TaHDZipI-2 in controlling several key processes underlying frost tolerance, transition to flowering and spike development. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Identification of Genes Associated with Lemon Floral Transition and Flower Development during Floral Inductive Water Deficits: A Hypothetical Model

PubMed Central

Li, Jin-Xue; Hou, Xiao-Jin; Zhu, Jiao; Zhou, Jing-Jing; Huang, Hua-Bin; Yue, Jian-Qiang; Gao, Jun-Yan; Du, Yu-Xia; Hu, Cheng-Xiao; Hu, Chun-Gen; Zhang, Jin-Zhi

2017-01-01

Water deficit is a key factor to induce flowering in many woody plants, but reports on the molecular mechanisms of floral induction and flowering by water deficit are scarce. Here, we analyzed the morphology, cytology, and different hormone levels of lemon buds during floral inductive water deficits. Higher levels of ABA were observed, and the initiation of floral bud differentiation was examined by paraffin sections analysis. A total of 1638 differentially expressed genes (DEGs) were identified by RNA sequencing. DEGs were related to flowering, hormone biosynthesis, or metabolism. The expression of some DEGs was associated with floral induction by real-time PCR analysis. However, some DEGs may not have anything to do with flowering induction/flower development; they may be involved in general stress/drought response. Four genes from the phosphatidylethanolamine-binding protein family were further investigated. Ectopic expression of these genes in Arabidopsis changed the flowering time of transgenic plants. Furthermore, the 5′ flanking region of these genes was also isolated and sequence analysis revealed the presence of several putative cis-regulatory elements, including basic elements and hormone regulation elements. The spatial and temporal expression patterns of these promoters were investigated under water deficit treatment. Based on these findings, we propose a model for citrus flowering under water deficit conditions, which will enable us to further understand the molecular mechanism of water deficit-regulated flowering in citrus. Highlight: Based on gene activity during floral inductive water deficits identified by RNA sequencing and genes associated with lemon floral transition, a model for citrus flowering under water deficit conditions is proposed. PMID:28659956

Precocious flowering in trees: the FLOWERING LOCUS T gene as a research and breeding tool in Populus.

PubMed

Zhang, Huanling; Harry, David E; Ma, Cathleen; Yuceer, Cetin; Hsu, Chuan-Yu; Vikram, Vikas; Shevchenko, Olga; Etherington, Elizabeth; Strauss, Steven H

2010-06-01

Expression of FLOWERING LOCUS T (FT) and its homologues has been shown to accelerate the onset of flowering in a number of plant species, including poplar (Populus spp.). The application of FT should be of particular use in forest trees, as it could greatly accelerate and enable new kinds of breeding and research. Recent evidence showing the extent to which FT is effective in promoting flowering in trees is discussed, and its effectiveness in poplar is reported. Results using one FT gene from Arabidopsis and two from poplar, all driven by a heat-inducible promoter, transformed into two poplar genotypes are also described. Substantial variation in flowering response was observed depending on the FT gene and genetic background. Heat-induced plants shorter than 30 cm failed to flower as well as taller plants. Plants exposed to daily heat treatments lasting 3 weeks tended to produce fewer abnormal flowers than those in heat treatments of shorter durations; increasing the inductive temperature from 37 degrees C to 40 degrees C produced similar benefits. Using optimal induction conditions, approximately 90% of transgenic plants could be induced to flower. When induced FT rootstocks were grafted with scions that lacked FT, flowering was only observed in rootstocks. The results suggest that a considerable amount of species- or genotype-specific adaptation will be required to develop FT into a reliable means for shortening the generation cycle for breeding in poplar.

Molecular Mapping of Flowering Time Major Genes and QTLs in Chickpea (Cicer arietinum L.)

PubMed Central

Mallikarjuna, Bingi P.; Samineni, Srinivasan; Thudi, Mahendar; Sajja, Sobhan B.; Khan, Aamir W.; Patil, Ayyanagowda; Viswanatha, Kannalli P.; Varshney, Rajeev K.; Gaur, Pooran M.

2017-01-01

Flowering time is an important trait for adaptation and productivity of chickpea in the arid and the semi-arid environments. This study was conducted for molecular mapping of genes/quantitative trait loci (QTLs) controlling flowering time in chickpea using F2 populations derived from four crosses (ICCV 96029 × CDC Frontier, ICC 5810 × CDC Frontier, BGD 132 × CDC Frontier and ICC 16641 × CDC Frontier). Genetic studies revealed monogenic control of flowering time in the crosses ICCV 96029 × CDC Frontier, BGD 132 × CDC Frontier and ICC 16641 × CDC Frontier, while digenic control with complementary gene action in ICC 5810 × CDC Frontier. The intraspecific genetic maps developed from these crosses consisted 75, 75, 68 and 67 markers spanning 248.8 cM, 331.4 cM, 311.1 cM and 385.1 cM, respectively. A consensus map spanning 363.8 cM with 109 loci was constructed by integrating four genetic maps. Major QTLs corresponding to flowering time genes efl-1 from ICCV 96029, efl-3 from BGD 132 and efl-4 from ICC 16641 were mapped on CaLG04, CaLG08 and CaLG06, respectively. The QTLs and linked markers identified in this study can be used in marker-assisted breeding for developing early maturing chickpea. PMID:28729871

The colour of creation: Gertrude Jekyll and the art of flowers.

PubMed

Bisgrove, Richard

2013-12-01

Flowers were central to the life and work of Gertrude Jekyll (1843-1932), one of the 20th century's most influential garden designers. Born of parents with interests across a broad range of the art-science spectrum, Miss Jekyll developed an early interest in many arts and crafts, including painting and gardening in particular. During her course at the Central School of Design in Kensington she studied closely the work of JMW Turner. Many of the compositional elements of Turner's paintings, especially his use of colour, can be seen in Miss Jekyll's subsequent designs for c. 250 gardens. The use of blue and yellow flowers to create a sense of light, and the contrast of cool blue flowers and grey foliage with vivid reds and oranges are recurrent themes in her planting schemes, but many other aspects of her designs also reflect her broad interest in the art, craft, and science of plant cultivation. She encouraged others to seek the satisfaction offered by gardening as an art, convinced that a life spent seeking perfection would gradually yield 'the power of intelligent combination, the nearest thing we can know to the mighty force of creation'.

A Jasmonate ZIM-Domain Protein NaJAZd Regulates Floral Jasmonic Acid Levels and Counteracts Flower Abscission in Nicotiana attenuata Plants

PubMed Central

Oh, Youngjoo; Baldwin, Ian T.; Galis, Ivan

2013-01-01

Jasmonic acid is an important regulator of plant growth, development and defense. The jasmonate-ZIM domain (JAZ) proteins are key regulators in jasmonate signaling ubiquitously present in flowering plants but their functional annotation remains largely incomplete. Recently, we identified 12 putative JAZ proteins in native tobacco, Nicotiana attenuata, and initiated systematic functional characterization of these proteins by reverse genetic approaches. In this report, Nicotiana attenuata plants silenced in the expression of NaJAZd (irJAZd) by RNA interference were used to characterize NaJAZd function. Although NaJAZd transcripts were strongly and transiently up-regulated in the rosette leaves by simulated herbivory treatment, we did not observe strong defense-related phenotypes, such as altered herbivore performance or the constitutive accumulation of defense-related secondary metabolites in irJAZd plants compared to wild type plants, both in the glasshouse and the native habitat of Nicotiana attenuata in the Great Basin Desert, Utah, USA. Interestingly, irJAZd plants produced fewer seed capsules than did wild type plants as a result of increased flower abscission in later stages of flower development. The early- and mid-developmental stages of irJAZd flowers had reduced levels of jasmonic acid and jasmonoyl-L-isoleucine, while fully open flowers had normal levels, but these were impaired in NaMYB305 transcript accumulations. Previously, NaMYB305-silenced plants were shown to have strong flower abscission phenotypes and contained lower NECTARIN 1 transcript levels, phenotypes which are copied in irJAZd plants. We propose that the NaJAZd protein is required to counteract flower abscission, possibly by regulating jasmonic acid and jasmonoyl-L-isoleucine levels and/or expression of NaMYB305 gene in Nicotiana attenuata flowers. This novel insight into the function of JAZ proteins in flower and seed development highlights the diversity of functions played by jasmonates

Genetic Architecture of Flowering-Time Variation in Brachypodium distachyon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Woods, Daniel P.; Bednarek, Ryland; Bouché, Frédéric

The transition to reproductive development is a crucial step in the plant life cycle, and the timing of this transition is an important factor in crop yields. Here, we report new insights into the genetic control of natural variation in flowering time in Brachypodium distachyon, a nondomesticated pooid grass closely related to cereals such as wheat (Triticum spp.) and barley (Hordeum vulgare L.). A recombinant inbred line population derived from a cross between the rapid-flowering accession Bd21 and the delayed-flowering accession Bd1-1 were grown in a variety of environmental conditions to enable exploration of the genetic architecture of flowering time.more » A genotyping-by-sequencing approach was used to develop SNP markers for genetic map construction, and quantitative trait loci (QTLs) that control differences in flowering time were identified. Many of the flowering-time QTLs are detected across a range of photoperiod and vernalization conditions, suggesting that the genetic control of flowering within this population is robust. The two major QTLs identified in undomesticated B. distachyon colocalize with VERNALIZATION1/PHYTOCHROME C and VERNALIZATION2, loci identified as flowering regulators in the domesticated crops wheat and barley. This suggests that variation in flowering time is controlled in part by a set of genes broadly conserved within pooid grasses.« less

Genetic Architecture of Flowering-Time Variation in Brachypodium distachyon

DOE PAGES

Woods, Daniel P.; Bednarek, Ryland; Bouché, Frédéric; ...

2016-10-14

The transition to reproductive development is a crucial step in the plant life cycle, and the timing of this transition is an important factor in crop yields. Here, we report new insights into the genetic control of natural variation in flowering time in Brachypodium distachyon, a nondomesticated pooid grass closely related to cereals such as wheat (Triticum spp.) and barley (Hordeum vulgare L.). A recombinant inbred line population derived from a cross between the rapid-flowering accession Bd21 and the delayed-flowering accession Bd1-1 were grown in a variety of environmental conditions to enable exploration of the genetic architecture of flowering time.more » A genotyping-by-sequencing approach was used to develop SNP markers for genetic map construction, and quantitative trait loci (QTLs) that control differences in flowering time were identified. Many of the flowering-time QTLs are detected across a range of photoperiod and vernalization conditions, suggesting that the genetic control of flowering within this population is robust. The two major QTLs identified in undomesticated B. distachyon colocalize with VERNALIZATION1/PHYTOCHROME C and VERNALIZATION2, loci identified as flowering regulators in the domesticated crops wheat and barley. This suggests that variation in flowering time is controlled in part by a set of genes broadly conserved within pooid grasses.« less

Unexpected Diversity during Community Succession in the Apple Flower Microbiome

PubMed Central

Shade, Ashley; McManus, Patricia S.; Handelsman, Jo

2013-01-01

ABSTRACT Despite its importance to the host, the flower microbiome is poorly understood. We report a culture-independent, community-level assessment of apple flower microbial diversity and dynamics. We collected flowers from six apple trees at five time points, starting before flowers opened and ending at petal fall. We applied streptomycin to half of the trees when flowers opened. Assessment of microbial diversity using tag pyrosequencing of 16S rRNA genes revealed that the apple flower communities were rich and diverse and dominated by members of TM7 and Deinococcus-Thermus, phyla about which relatively little is known. From thousands of taxa, we identified six successional groups with coherent dynamics whose abundances peaked at different times before and after bud opening. We designated the groups Pioneer, Early, Mid, Late, Climax, and Generalist communities. The successional pattern was attributed to a set of prevalent taxa that were persistent and gradually changing in abundance. These taxa had significant associations with other community members, as demonstrated with a cooccurrence network based on local similarity analysis. We also detected a set of less-abundant, transient taxa that contributed to general tree-to-tree variability but not to the successional pattern. Communities on trees sprayed with streptomycin had slightly lower phylogenetic diversity than those on unsprayed trees but did not differ in structure or succession. Our results suggest that changes in apple flower microbial community structure are predictable over the life of the flower, providing a basis for ecological understanding and disease management. PMID:23443006

Unexpected diversity during community succession in the apple flower microbiome.

PubMed

Shade, Ashley; McManus, Patricia S; Handelsman, Jo

2013-02-26

Despite its importance to the host, the flower microbiome is poorly understood. We report a culture-independent, community-level assessment of apple flower microbial diversity and dynamics. We collected flowers from six apple trees at five time points, starting before flowers opened and ending at petal fall. We applied streptomycin to half of the trees when flowers opened. Assessment of microbial diversity using tag pyrosequencing of 16S rRNA genes revealed that the apple flower communities were rich and diverse and dominated by members of TM7 and Deinococcus-Thermus, phyla about which relatively little is known. From thousands of taxa, we identified six successional groups with coherent dynamics whose abundances peaked at different times before and after bud opening. We designated the groups Pioneer, Early, Mid, Late, Climax, and Generalist communities. The successional pattern was attributed to a set of prevalent taxa that were persistent and gradually changing in abundance. These taxa had significant associations with other community members, as demonstrated with a cooccurrence network based on local similarity analysis. We also detected a set of less-abundant, transient taxa that contributed to general tree-to-tree variability but not to the successional pattern. Communities on trees sprayed with streptomycin had slightly lower phylogenetic diversity than those on unsprayed trees but did not differ in structure or succession. Our results suggest that changes in apple flower microbial community structure are predictable over the life of the flower, providing a basis for ecological understanding and disease management. Flowering plants (angiosperms) represent a diverse group of an estimated 400,000 species, and their successful cultivation is essential to agriculture. Yet fundamental knowledge of flower-associated microbiotas remains largely unknown. Even less well understood are the changes that flower microbial communities experience through time. Flowers are

Functional homogenization of flower visitor communities with urbanization.

PubMed

Deguines, Nicolas; Julliard, Romain; de Flores, Mathieu; Fontaine, Colin

2016-04-01

Land-use intensification and resulting habitat loss are put forward as the main causes of flower visitor decline. However, the impact of urbanization, the prime driver of land-use intensification in Europe, is poorly studied. In particular, our understanding of whether and how it affects the composition and functioning of flower visitor assemblages is scant, yet required to cope with increasing urbanization worldwide. Here, we use a nation-wide dataset of plant-flower visitor (Coleoptera, Diptera, Hymenoptera, Lepidoptera) interactions sampled by citizen scientists following a standardized protocol to assess macroecological changes in richness and composition of flower visitor communities with urbanization. We measured the community composition by quantifying the relative occurrence of generalist and specialist flower visitors based on their specialisation on flowering plant families. We show that urbanization is associated with reduced flower visitor richness and a shift in community composition toward generalist insects, indicating a modification of the functional composition of communities. These results suggest that urbanization affects not only the richness of flower visitor assemblages but may also cause their large-scale functional homogenization. Future research should focus on designing measures to reconcile urban development with flower visitor conservation.

Dormancy release and flowering time in Ziziphus jujuba Mill., a "direct flowering" fruit tree, has a facultative requirement for chilling.

PubMed

Meir, Michal; Ransbotyn, Vanessa; Raveh, Eran; Barak, Simon; Tel-Zur, Noemi; Zaccai, Michele

2016-03-15

In deciduous fruit trees, the effect of chilling on flowering has mostly been investigated in the "indirect flowering" group, characterized by a period of rest between flower bud formation and blooming. In the present study, we explored the effects of chilling and chilling deprivation on the flowering of Ziziphus jujuba, a temperate deciduous fruit tree belonging to the "direct flowering" group, in which flower bud differentiation, blooming and fruit development occur after dormancy release, during a single growing season. Dormancy release, vegetative growth and flowering time in Z. jujuba cv. Ben-Li were assessed following several treatments of chilling. Chilling treatments quantitatively decreased the timing of vegetative bud dormancy release, thereby accelerating flowering, but had no effect on the time from dormancy release to flowering. Trees grown at a constant temperature of 25°C, without chilling, broke dormancy and flowered, indicating the facultative character of chilling in this species. We measured the expression of Z. jujuba LFY and AP1 homologues (ZjLFY and ZjAP1). Chilling decreased ZjLFY expression in dormant vegetative buds but had no effect on ZjAP1expression, which reached peak expression before dormancy release and at anthesis. In conclusion, chilling is not obligatory for dormancy release of Z. jujuba cv. Ben-Li vegetative buds. However, the exposure to chilling during dormancy does accelerate vegetative bud dormancy release and flowering. Copyright © 2016 Elsevier GmbH. All rights reserved.

Successful boll development after ovary damage during emasculation of upland cotton flowers

USDA-ARS?s Scientific Manuscript database

Gossypium hirsutum flowers are easily emasculated by splitting the staminal column with the fingernail and removing the corolla and androecium. However, any damage to the ovary is considered detrimental to successful boll formation and damaged flowers are typically discarded. This study evaluated ...

Flowering in space

NASA Astrophysics Data System (ADS)

Zheng, Hui Qiong

2018-05-01

The reproductive success of plants is often dependent on their flowering time being adapted to the terrestrial environment, in which gravity remain constant. Whether plants can follow the same rule to determine their flowering time under microgravity in space is unknown. Although numerous attempts have been made to grow a plant through a complete life cycle in space, apparently no published information exists concerning the flowering control of plants under microgravity in space. Here, we focused on two aspects. Firstly the environmental and intrinsic factors under microgravity related to flowering control. Secondly, the plant-derived regulators are involved in flowering control under microgravity condition. The potential environmental and intrinsic factors affect plant flowering under microgravity may include light, biological circadian clock as well as long-distance signaling, while the plant-derived flowering regulators in response to microgravity could include gibberellic acid, ethylene, microRNA and sugar. The results we have obtained from the space experiments on board the Chinese recoverable satellites (the SJ-8 and the SJ-10) and the experiment on the Chinese space lab TG-2 are also introduced. We conclude by suggesting that long-term space experiments from successive generations and a systematic analysis of regulatory networks at the molecular level is needed to understand the mechanism of plant flowering control under microgravity conditions in space.

Tomato Flower Abnormalities Induced by Low Temperatures Are Associated with Changes of Expression of MADS-Box Genes1

PubMed Central

Lozano, Rafael; Angosto, Trinidad; Gómez, Pedro; Payán, Carmen; Capel, Juan; Huijser, Peter; Salinas, Julio; Martínez-Zapater, José M.

1998-01-01

Flower and fruit development in tomato (Lycopersicon esculentum Mill.) were severely affected when plants were grown at low temperatures, displaying homeotic and meristic transformations and alterations in the fusion pattern of the organs. Most of these homeotic transformations modified the identity of stamens and carpels, giving rise to intermediate organs. Complete homeotic transformations were rarely found and always affected organs of the reproductive whorls. Meristic transformations were also commonly observed in the reproductive whorls, which developed with an excessive number of organs. Scanning electron microscopy revealed that meristic transformations take place very early in the development of the flower and are related to a significant increase in the floral meristem size. However, homeotic transformations should occur later during the development of the organ primordia. Steady-state levels of transcripts corresponding to tomato MADS-box genes TM4, TM5, TM6, and TAG1 were greatly increased by low temperatures and could be related to these flower abnormalities. Moreover, in situ hybridization analyses showed that low temperatures also altered the stage-specific expression of TM4. PMID:9576778

The quest for epigenetic regulation underlying unisexual flower development in Cucumis melo.

PubMed

Latrasse, David; Rodriguez-Granados, Natalia Y; Veluchamy, Alaguraj; Mariappan, Kiruthiga Gayathri; Bevilacqua, Claudia; Crapart, Nicolas; Camps, Celine; Sommard, Vivien; Raynaud, Cécile; Dogimont, Catherine; Boualem, Adnane; Benhamed, Moussa; Bendahmane, Abdelhafid

2017-01-01

Melon ( Cucumis melo ) is an important vegetable crop from the Cucurbitaceae family and a reference model specie for sex determination, fruit ripening and vascular fluxes studies. Nevertheless, the nature and role of its epigenome in gene expression regulation and more specifically in sex determination remains largely unknown. We have investigated genome wide H3K27me3 and H3K9ac histone modifications and gene expression dynamics, in five melon organs. H3K9ac and H3K27me3 were mainly distributed along gene-rich regions and constrained to gene bodies. H3K9ac was preferentially located at the TSS, whereas H3K27me3 distributed uniformly from TSS to TES. As observed in other species, H3K9ac and H3K27me3 correlated with high and low gene expression levels, respectively. Comparative analyses of unisexual flowers pointed out sex-specific epigenetic states of TFs involved in ethylene response and flower development. Chip-qPCR analysis of laser dissected carpel and stamina primordia, revealed sex-specific histone modification of MADS-box genes. Using sex transition mutants, we demonstrated that the female promoting gene, CmACS11 , represses the expression of the male promoting gene CmWIP1 via deposition of H3K27me3. Our findings reveal the organ-specific landscapes of H3K9ac and H3K27me3 in melon. Our results also provide evidence that the sex determination genes recruit histone modifiers to orchestrate unisexual flower development in monoecious species.

Trees as huge flowers and flowers as oversized floral guides: the role of floral color change and retention of old flowers in Tibouchina pulchra

PubMed Central

Brito, Vinícius L. G.; Weynans, Kevin; Sazima, Marlies; Lunau, Klaus

2015-01-01

Floral color changes and retention of old flowers are frequently combined phenomena restricted to the floral guide or single flowers in few-flowered inflorescences. They are thought to increase the attractiveness over long distances and to direct nearby pollinators toward the rewarding flowers. In Tibouchina pulchra, a massively flowering tree, the whole flower changes its color during anthesis. On the first day, the flowers are white and on the next 3 days, they change to pink. This creates a new large-scale color pattern in which the white pre-changed flowers contrast against the pink post-changed ones over the entire tree. We describe the spectral characteristics of floral colors of T. pulchra and test bumblebees’ response to this color pattern when viewed at different angles (simulating long and short distances). The results indicated the role of different color components in bumblebee attraction and the possible scenario in which this flower color pattern has evolved. We tested bumblebees’ preference for simulated trees with 75% pink and 25% white flowers resembling the color patterns of T. pulchra, and trees with green leaves and pink flowers (control) in long-distance approach. We also compared an artificial setting with three pink flowers and one white flower (T. pulchra model) against four pink flowers with white floral guides (control) in short-distance approach. Bumblebees spontaneously preferred the simulated T. pulchra patterns in both approaches despite similar reward. Moreover, in short distances, pollinator visits to peripheral, non-rewarding flowers occurred only half as frequently in the simulated T. pulchra when compared to the control. Thefore, this exceptional floral color change and the retention of old flowers in T. pulchra favors the attraction of pollinators over long distances in a deception process while it honestly directs them toward the rewarding flowers at short distances possibly exploring their innate color preferences. PMID

Say it with flowers: flowering acceleration by root communication.

PubMed

Falik, Omer; Hoffmann, Ishay; Novoplansky, Ariel

2014-01-01

The timing of reproduction is a critical determinant of fitness, especially in organisms inhabiting seasonal environments. Increasing evidence suggests that inter-plant communication plays important roles in plant functioning. Here, we tested the hypothesis that flowering coordination can involve communication between neighboring plants. We show that soil leachates from Brassica rapa plants growing under long-day conditions accelerated flowering and decreased allocation to vegetative organs in target plants growing under non-inductive short-day conditions. The results suggest that besides endogenous signaling and external abiotic cues, flowering timing may involve inter-plant communication, mediated by root exudates. The study of flowering communication is expected to illuminate neglected aspects of plant reproductive interactions and to provide novel opportunities for controlling the timing of plant reproduction in agricultural settings.

Say it with flowers: Flowering acceleration by root communication.

PubMed

Falik, Omer; Hoffmann, Ishay; Novoplansky, Ariel

2014-01-01

The timing of reproduction is a critical determinant of fitness, especially in organisms inhabiting seasonal environments. Increasing evidence suggests that inter-plant communication plays important roles in plant functioning. Here, we tested the hypothesis that flowering coordination can involve communication between neighboring plants. We show that soil leachates from Brassica rapa plants growing under long-day conditions accelerated flowering and decreased allocation to vegetative organs in target plants growing under non-inductive short-day conditions. The results suggest that besides endogenous signaling and external abiotic cues, flowering timing may involve inter-plant communication, mediated by root exudates. The study of flowering communication is expected to illuminate neglected aspects of plant reproductive interactions and to provide novel opportunities for controlling the timing of plant reproduction in agricultural settings.

Pollinator-mediated selection on floral display and flowering time in the perennial herb Arabidopsis lyrata.

PubMed

Sandring, Saskia; Agren, Jon

2009-05-01

The evolution of floral display and flowering time in animal-pollinated plants is commonly attributed to pollinator-mediated selection. Yet, the causes of selection on flowering phenology and traits contributing to floral display have rarely been tested experimentally in natural populations. We quantified phenotypic selection on morphological and phenological characters in the perennial, outcrossing herb Arabidopsis lyrata in two years using female reproductive success as a proxy of fitness. To determine whether selection on floral display and flowering phenology can be attributed to interactions with pollinators, selection was quantified both for open-pollinated controls and for plants receiving supplemental hand-pollination. We documented directional selection for many flowers, large petals, late start of flowering, and early end of flowering. Seed output was pollen-limited in both years and supplemental hand-pollination reduced the magnitude of selection on number of flowers, and reversed the direction of selection on end of flowering. The results demonstrate that interactions with pollinators may affect the strength of selection on floral display and the direction of selection on phenology of flowering in natural plant populations. They thus support the contention that pollinators can drive the evolution of both floral display and flowering time.

Flower thermoregulation facilitates fertilization in Asian sacred lotus

PubMed Central

Li, Jiao-Kun; Huang, Shuang-Quan

2009-01-01

Background and Aims The thermoregulatory flower of the Asian sacred lotus (Nelumbo nucifera) can maintain a relatively stable temperature despite great variations in ambient temperature during anthesis. The thermoregulation has been hypothesized to offer a direct energy reward for pollinators in lotus flowers. This study aims to examine whether the stable temperature maintained in the floral chamber influences the fertilization process and seed development. Methods An artificial refrigeration instrument was employed to cool flowers during the fertilization process and post-fertilization period in an experimental population. The effect of temperature on post-pollination events was also examined by removing petals in two field populations. Key Results Treatments with low floral temperature did not reduce stigma receptivity or pollen viability in undehisced anthers. Low temperature during the fertilization period significantly decreased seed set per flower but low temperature during the phase of seed development had no effect, suggesting that temperature regulation by lotus flowers facilitated fertilization success. Hand-pollination treatments in two field populations indicated that seed set of flowers with petals removed was lower than that of intact flowers in north China, where ambient temperatures are low, but not in south China, confirming that reducing the temperature of carpels did influence post-pollination events. Conclusions The experiments suggest that floral thermoregulation in lotus could enhance female reproductive success by facilitating fertilization. PMID:19282320

Grass meristems II: inflorescence architecture, flower development and meristem fate.

PubMed

Tanaka, Wakana; Pautler, Michael; Jackson, David; Hirano, Hiro-Yuki

2013-03-01

Plant development depends on the activity of various types of meristems that generate organs such as leaves and floral organs throughout the life cycle. Grass species produce complex inflorescences and unique flowers. The grass inflorescence is composed of different types of branches, including a specialized branch called a spikelet. The spikelet is a special unit of the inflorescence and forms one to several florets, depending on the species. In the floret, floral organs such as perianth organs, carpels and stamens are formed. In Arabidopsis, because the inflorescence meristem (IM) forms the floral meristems (FMs) directly on its flanks, the change of meristem fate is relatively simple. In contrast, in grasses, different types of meristem, such as the IM, the branch meristem (BM), the spikelet pair meristem (SPM) in some grasses, the spikelet meristem (SM) and the FM, are responsible for the elaboration of their complex inflorescences and flowers. Therefore, sequential changes of meristem fate are required, and a number of genes involved in the specification of the fate of each meristem have been identified. In this review, we focus on the following issues concerning the fate of the reproductive meristems in two grass species, maize (Zea mays) and rice (Oryza sativa): (i) meristem regulation during inflorescence development; (ii) specification and fate change of the BM and the SM; (iii) determinacy of the FM; and (iv) communication between the meristem and lateral organs.

Cold Tolerance of the Male Gametophyte during Germination and Tube Growth Depends on the Flowering Time

PubMed Central

Wagner, Johanna; Gastl, Evelyn; Kogler, Martin; Scheiber, Michaela

2016-01-01

In temperate climates, most plants flower during the warmer season of the year to avoid negative effects of low temperatures on reproduction. Nevertheless, few species bloom in midwinter and early spring despite severe and frequent frosts at that time. This raises the question of adaption of sensible progamic processes such as pollen germination and pollen tube growth to low temperatures. The performance of the male gametophyte of 12 herbaceous lowland species flowering in different seasons was examined in vitro at different test temperatures using an easy to handle testing system. Additionally, the capacity to recover after the exposure to cold was checked. We found a clear relationship between cold tolerance of the activated male gametophyte and the flowering time. In most summer-flowering species, pollen germination stopped between 1 and 5 °C, whereas pollen of winter and early spring flowering species germinated even at temperatures below zero. Furthermore, germinating pollen was exceptionally frost tolerant in cold adapted plants, but suffered irreversible damage already from mild sub-zero temperatures in summer-flowering species. In conclusion, male gametophytes show a high adaptation potential to cold which might exceed that of female tissues. For an overall assessment of temperature limits for sexual reproduction it is therefore important to consider female functions as well. PMID:28036058

Mid-Cretaceous charred fossil flowers reveal direct observation of arthropod feeding strategies

PubMed Central

Hartkopf-Fröder, Christoph; Rust, Jes; Wappler, Torsten; Friis, Else Marie; Viehofen, Agnes

2012-01-01

Although plant–arthropod relationships underpin the dramatic rise in diversity and ecological dominance of flowering plants and their associated arthropods, direct observations of such interactions in the fossil record are rare, as these ephemeral moments are difficult to preserve. Three-dimensionally preserved charred remains of Chloranthistemon flowers from the Late Albian to Early Cenomanian of Germany preserve scales of mosquitoes and an oribatid mite with mouthparts inserted into the pollen sac. Mosquitoes, which today are frequent nectar feeders, and the mite were feeding on pollen at the time wildfire consumed the flowers. These findings document directly arthropod feeding strategies and their role in decomposition. PMID:21900310

Flowering in Xanthium strumarium

PubMed Central

Leonard, Maggy; Kinet, Jean-Marie; Bodson, Monique; Havelange, Andrée; Jacqmard, Annie; Bernier, Georges

1981-01-01

Vegetative plants of Xanthium strumarium L. grown in long days were induced to flower by exposure to one or several 16-hour dark periods. The distribution of male and female inflorescences on the flowering shoot was described, and a scoring system was designed to assess the development of the female inflorescences. The time of movement of the floral stimulus out of the induced leaf and the timing of action of high temperature were shown to be similar for both the apical male and lateral female inflorescences. Strong photoperiodic induction of the plants favored female sex expression, while maleness was enhanced by exogenous gibberellic acid. The problem of the control of sex expression in Xanthium is discussed in relation to the distribution pattern of male and female inflorescences on the flowering shoot and to the state of the meristem at the time of the arrival of the floral stimulus. Images PMID:16661844

Laser capture microdissection to study flower morphogenesis

NASA Astrophysics Data System (ADS)

Pawełkowicz, Magdalena Ewa; Skarzyńska, Agnieszka; Kowalczuk, Cezary; PlÄ der, Wojciech; Przybecki, Zbigniew

2017-08-01

Laser Capture Microdissection (LCM) is a sample preparation microscopic method that enables isolation of an interesting cell or cells population from human, animal or plant tissue. This technique allows for obtaining pure sample from heterogeneous mixture. From isolated cells, it is possible to obtain the appropriate quality material used for genomic research in transcriptomics, proteomics and metabolomics. We used LCM method to study flower morphogenesis and specific bud's organ organization and development. The genes expression level in developing flower buds of male (B10) and female (2gg) lines were analyzed with qPCR. The expression was checked for stamen and carpel primordia obtained with LCM and for whole flower buds at successive stages of growth.

Recent advancements to study flowering time in almond and other Prunus species

PubMed Central

Sánchez-Pérez, Raquel; Del Cueto, Jorge; Dicenta, Federico; Martínez-Gómez, Pedro

2014-01-01

Flowering time is an important agronomic trait in almond since it is decisive to avoid the late frosts that affect production in early flowering cultivars. Evaluation of this complex trait is a long process because of the prolonged juvenile period of trees and the influence of environmental conditions affecting gene expression year by year. Consequently, flowering time has to be studied for several years to have statistical significant results. This trait is the result of the interaction between chilling and heat requirements. Flowering time is a polygenic trait with high heritability, although a major gene Late blooming (Lb) was described in “Tardy Nonpareil.” Molecular studies at DNA level confirmed this polygenic nature identifying several genome regions (Quantitative Trait Loci, QTL) involved. Studies about regulation of gene expression are scarcer although several transcription factors have been described as responsible for flowering time. From the metabolomic point of view, the integrated analysis of the mechanisms of accumulation of cyanogenic glucosides and flowering regulation through transcription factors open new possibilities in the analysis of this complex trait in almond and in other Prunus species (apricot, cherry, peach, plum). New opportunities are arising from the integration of recent advancements including phenotypic, genetic, genomic, transcriptomic, and metabolomics studies from the beginning of dormancy until flowering. PMID:25071812

Many to flower, few to fruit: the reproductive biology of Hamamelis virginiana (Hamamelidaceae).

PubMed

Anderson, Gregory J; Hill, James D

2002-01-01

Hamamelis virginiana flowers from late September to late November. In 1977, we began studying the reproductive biology of this eastern North American arborescent shrub by examining floral phenology and rewards, pollen-ovule ratios, breeding system, pollination, pollinator and resource limitation, and seed dispersal. The homogamous, self-incompatible flowers emit a faint odor, bear nectar with sucrose ratios typical of bee- and fly-pollinated flowers, and produce abundant sticky pollen. Flowers were visited infrequently by insects representing six orders. Flies were the most common floral visitors, specifically members of the genus Bradysia, but small bees also carried high percentages of Hamamelis pollen. Despite high pollen/ovule ratios (11 445 grains/ovule), bees and flies are likely pollinators, as experiments indicate wind pollination is less likely. Pollen quantity and resource availability did not appear to limit reproductive output, but pollen quality did. Tests of >40 000 flowers showed natural fruit set to be <1%. The flowering time, breeding system, and clumped distribution of plants, likely due in part to limited seed dispersal, combine to yield this remarkably low fruit set. Because all other species of Hamamelis flower from late winter to early summer, it may be that H. virginiana evolved a fall flowering phenology to avoid competition for pollinators with the closely related H. vernalis.

Susceptibility of blackberry flowers to freezing temperatures

USDA-ARS?s Scientific Manuscript database

Injury of tight buds, open flowers and green fruit often occur in fruit crops during spring frost events. In this study, freezing tolerance of ‘Triple Crown’ blackberry flowers at different reproductive stages of development (tight bud to green drupe) was determined using two methods. One method i...

Identification of successive flowering phases highlights a new genetic control of the flowering pattern in strawberry

PubMed Central

Perrotte, Justine; Guédon, Yann; Gaston, Amèlia; Denoyes, Béatrice

2016-01-01

The genetic control of the switch between seasonal and perpetual flowering has been deciphered in various perennial species. However, little is known about the genetic control of the dynamics of perpetual flowering, which changes abruptly at well-defined time instants during the growing season. Here, we characterize the perpetual flowering pattern and identify new genetic controls of this pattern in the cultivated strawberry. Twenty-one perpetual flowering strawberry genotypes were phenotyped at the macroscopic scale for their course of emergence of inflorescences and stolons during the growing season. A longitudinal analysis based on the segmentation of flowering rate profiles using multiple change-point models was conducted. The flowering pattern of perpetual flowering genotypes takes the form of three or four successive phases: an autumn-initiated flowering phase, a flowering pause, and a single stationary perpetual flowering phase or two perpetual flowering phases, the second one being more intense. The genetic control of flowering was analysed by quantitative trait locus mapping of flowering traits based on these flowering phases. We showed that the occurrence of a fourth phase of intense flowering is controlled by a newly identified locus, different from the locus FaPFRU, controlling the switch between seasonal and perpetual flowering behaviour. The role of this locus was validated by the analysis of data obtained previously during six consecutive years. PMID:27664957

Analysis of the Arabidopsis superman allelic series and the interactions with other genes demonstrate developmental robustness and joint specification of male-female boundary, flower meristem termination and carpel compartmentalization.

PubMed

Breuil-Broyer, Stéphanie; Trehin, Christophe; Morel, Patrice; Boltz, Véronique; Sun, Bo; Chambrier, Pierre; Ito, Toshiro; Negrutiu, Ioan

2016-04-01

SUPERMAN is a cadastral gene controlling the sexual boundary in the flower. The gene's functions and role in flower development and evolution have remained elusive. The analysis of a contrasting SUP allelic series (for which the names superman, superwoman and supersex have been coined) makes it possible to distinguish early vs. late regulatory processes at the flower meristem centre to which SUP is an important contributor. Their understanding is essential in further addressing evolutionary questions linking bisexuality and flower meristem homeostasis. Inter-allelic comparisons were carried out and SUP interactions with other boundary factors and flower meristem patterning and homeostasis regulators (such as CLV, WUS, PAN, CUC, KNU, AG, AP3/PI, CRC and SPT) have been evaluated at genetic, molecular, morphological and histological levels. Early SUP functions include mechanisms of male-female (sexual) boundary specification, flower mersitem termination and control of stamen number. A SUP-dependent flower meristem termination pathway is identified and analysed. Late SUP functions play a role in organ morphogenesis by controlling intra-whorl organ separation and carpel medial region formation. By integrating early and late SUP functions, and by analyzing in one single experiment a series of SUP genetic interactions, the concept of meristematic 'transference' (cascade) - a regulatory bridging process redundantly and sequentially co-ordinating the triggering and completion of flower meristem termination, and carpel margin meristem and placenta patterning - is proposed. Taken together, the results strongly support the view that SUP(-type) function(s) have been instrumental in resolving male/female gradients into sharp male and female identities (whorls, organs) and in enforcing flower homeostasis during evolution. This has probably been achieved by incorporating the meristem patterning system of the floral axis into the female/carpel programme. © The Author 2016

Analysis of the Arabidopsis superman allelic series and the interactions with other genes demonstrate developmental robustness and joint specification of male–female boundary, flower meristem termination and carpel compartmentalization

PubMed Central

Breuil-Broyer, Stéphanie; Trehin, Christophe; Morel, Patrice; Boltz, Véronique; Sun, Bo; Chambrier, Pierre; Ito, Toshiro; Negrutiu, Ioan

2016-01-01

Background and Aims SUPERMAN is a cadastral gene controlling the sexual boundary in the flower. The gene’s functions and role in flower development and evolution have remained elusive. The analysis of a contrasting SUP allelic series (for which the names superman, superwoman and supersex have been coined) makes it possible to distinguish early vs. late regulatory processes at the flower meristem centre to which SUP is an important contributor. Their understanding is essential in further addressing evolutionary questions linking bisexuality and flower meristem homeostasis. Methods Inter-allelic comparisons were carried out and SUP interactions with other boundary factors and flower meristem patterning and homeostasis regulators (such as CLV, WUS, PAN, CUC, KNU, AG, AP3/PI, CRC and SPT) have been evaluated at genetic, molecular, morphological and histological levels. Key Results Early SUP functions include mechanisms of male–female (sexual) boundary specification, flower mersitem termination and control of stamen number. A SUP-dependent flower meristem termination pathway is identified and analysed. Late SUP functions play a role in organ morphogenesis by controlling intra-whorl organ separation and carpel medial region formation. By integrating early and late SUP functions, and by analyzing in one single experiment a series of SUP genetic interactions, the concept of meristematic ‘transference’ (cascade) – a regulatory bridging process redundantly and sequentially co-ordinating the triggering and completion of flower meristem termination, and carpel margin meristem and placenta patterning – is proposed. Conclusions Taken together, the results strongly support the view that SUP(-type) function(s) have been instrumental in resolving male/female gradients into sharp male and female identities (whorls, organs) and in enforcing flower homeostasis during evolution. This has probably been achieved by incorporating the meristem patterning system of the floral

Expression of the poplar Flowering Locus T1 (FT1) gene reduces the generation time in plum (Prunus domestica L.)

USDA-ARS?s Scientific Manuscript database

Plums normally begin to flower and fruit three to seven years from seed. To shorten this generation time, early flowering plum genotypes were produced by transforming plum hypocotyls with the poplar (Populus trichocarpa) Flowering Locus T1 (PtFT1) gene. Ectopic expression of 35S::PtFT1 induced ear...

Effects of abscisic acid on ethylene biosynthesis and perception in Hibiscus rosa-sinensis L. flower development

PubMed Central

Trivellini, Alice; Ferrante, Antonio; Vernieri, Paolo; Serra, Giovanni

2011-01-01

The effect of the complex relationship between ethylene and abscisic acid (ABA) on flower development and senescence in Hibiscus rosa-sinensis L. was investigated. Ethylene biosynthetic (HrsACS and HrsACO) and receptor (HrsETR and HrsERS) genes were isolated and their expression evaluated in three different floral tissues (petals, style–stigma plus stamens, and ovaries) of detached buds and open flowers. This was achieved through treatment with 0.1 mM 1-aminocyclopropane-1-carboxylic acid (ACC) solution, 500 nl l−1 methylcyclopropene (1-MCP), and 0.1 mM ABA solution. Treatment with ACC and 1-MCP confirmed that flower senescence in hibiscus is ethylene dependent, and treatment with exogenous ABA suggested that ABA may play a role in this process. The 1-MCP impeded petal in-rolling and decreased ABA content in detached open flowers after 9 h. This was preceded by an earlier and sequential increase in ABA content in 1-MCP-treated petals and style–stigma plus stamens between 1 h and 6 h. ACC treatment markedly accelerated flower senescence and increased ethylene production after 6 h and 9 h, particularly in style–stigma plus stamens. Ethylene evolution was positively correlated in these floral tissues with the induction of the gene expression of ethylene biosynthetic and receptor genes. Finally, ABA negatively affected the ethylene biosynthetic pathway and tissue sensitivity in all flower tissues. Transcript abundance of HrsACS, HrsACO, HrsETR, and HrsERS was reduced by exogenous ABA treatment. This research underlines the regulatory effect of ABA on the ethylene biosynthetic and perception machinery at a physiological and molecular level when inhibitors or promoters of senescence are exogenously applied. PMID:21841180

Spatial expression dynamics of Men-9 delineate the third floral whorl in male and female flowers of dioecious Silene latifolia.

PubMed

Robertson, S E; Li, Y; Scutt, C P; Willis, M E; Gilmartin, P M

1997-07-01

Sex determination in Silene latifolia is controlled by heteromorphic sex chromosomes. Female flowers have five fused carpels and ten arrested stamen primordia. The male-determining Y chromosome overrides female development to suppress carpel formation and promote stamen development. The isolation and characterization of two S. latifolia. Male enhanced cDNAs, Men-9a and Men-9b, which probably represent different alleles of a novel gene are reported here. Men-9a and Men-9b share 91.8% coding sequence nucleotide identity, yet only 85.4% amino acid identity. The Men-9 cDNAs are related to the previously reported MROS3 cDNA from S. latifolia. However, MROS3 is not present in the S. latifolia population used in these studies and the expression dynamics of Men-9a and Men-9b contrast dramatically with those reported for MROS3. Men-9 cDNAs are expressed primarily in anthers of young male flowers, with highest expression in 1-2 mm buds. Men-9 expression is also observed at a low level in female flowers. In situ hybridization analysis reveals two phases of Men-9 expression. The first phase is during a common stage of early stamen development in male and female flowers prior to stamen arrest in female flowers. The second phase of Men-9 expression is maximal in the epidermis and endothecium of Y chromosome- and Ustilago violacea-induced stamens; expression in male and female flowers extends to the epidermis of the staminal nectaries with strict boundaries at the second and fourth whorls, Men-9 gene expression therefore delineates the boundaries of the third floral whorl in S. latifolia flowers.

Comparative transcriptomic analyses of normal and malformed flowers in sugar apple (Annona squamosa L.) to identify the differential expressed genes between normal and malformed flowers.

PubMed

Liu, Kaidong; Li, Haili; Li, Weijin; Zhong, Jundi; Chen, Yan; Shen, Chenjia; Yuan, Changchun

2017-10-23

Sugar apple (Annona squamosa L.), a popular fruit with high medicinal and nutritional properties, is widely cultivated in tropical South Asia and America. The malformed flower is a major cause for a reduction in production of sugar apple. However, little information is available on the differences between normal and malformed flowers of sugar apple. To gain a comprehensive perspective on the differences between normal and malformed flowers of sugar apple, cDNA libraries from normal and malformation flowers were prepared independently for Illumina sequencing. The data generated a total of 70,189,896 reads that were integrated and assembled into 55,097 unigenes with a mean length of 783 bp. A large number of differentially expressed genes (DEGs) were identified. Among these DEGs, 701 flower development-associated transcript factor encoding genes were included. Furthermore, a large number of flowering- and hormone-related DEGs were also identified, and most of these genes were down-regulated expressed in the malformation flowers. The expression levels of 15 selected genes were validated using quantitative-PCR. The contents of several endogenous hormones were measured. The malformed flowers displayed lower endogenous hormone levels compared to the normal flowers. The expression data as well as hormone levels in our study will serve as a comprehensive resource for investigating the regulation mechanism involved in floral organ development in sugar apple.

Spatial and temporal transcriptome changes occurring during flower opening and senescence of the ephemeral hibiscus flower, Hibiscus rosa-sinensis

PubMed Central

Trivellini, Alice; Cocetta, Giacomo; Hunter, Donald A.; Vernieri, Paolo; Ferrante, Antonio

2016-01-01

Flowers are complex systems whose vegetative and sexual structures initiate and die in a synchronous manner. The rapidity of this process varies widely in flowers, with some lasting for months while others such as Hibiscus rosa-sinensis survive for only a day. The genetic regulation underlying these differences is unclear. To identify key genes and pathways that coordinate floral organ senescence of ephemeral flowers, we identified transcripts in H. rosa-sinensis floral organs by 454 sequencing. During development, 2053 transcripts increased and 2135 decreased significantly in abundance. The senescence of the flower was associated with increased abundance of many hydrolytic genes, including aspartic and cysteine proteases, vacuolar processing enzymes, and nucleases. Pathway analysis suggested that transcripts altering significantly in abundance were enriched in functions related to cell wall-, aquaporin-, light/circadian clock-, autophagy-, and calcium-related genes. Finding enrichment in light/circadian clock-related genes fits well with the observation that hibiscus floral development is highly synchronized with light and the hypothesis that ageing/senescence of the flower is orchestrated by a molecular clock. Further study of these genes will provide novel insight into how the molecular clock is able to regulate the timing of programmed cell death in tissues. PMID:27591432

Overexpression of a novel chrysanthemum SUPERMAN-like gene in tobacco affects lateral bud outgrowth and flower organ development.

PubMed

Liu, Qing-Lin; Xu, Ke-Dong; Ma, Nan; Zhao, Liang-Jun; Xi, Lin

2014-04-01

Previous studies have shown that the SUP genes play important roles in flower development and plant growth and morphogenesis. In this study, we isolated and characterized a SUPERMAN-like gene DgSZFP from chrysanthemum. DgSZFP contains one conserved Cys2/His2-type zinc finger motifs in the N-terminal region and an EAR-box in C-terminus. Its expression was significantly higher in nodes, flower buds, disc stamens, and petals than in the other tissues. Overexpression of DgSZFP in tobacco resulted in enhanced branching, reduced plant height, increased the width of petal tubes, produced the staminoid petals and petaloid stamens in flowers, and enhanced the seed weight and size. In addition, DgSZFP-overexpression tobacco plants accumulated high concentrations of cytokinin and chlorophyll. These results suggest that DgSZFP may be the candidate gene for regulating branching and floral organ development in chrysanthemum. Crown Copyright © 2014. Published by Elsevier Masson SAS. All rights reserved.

Multisensory integration in Lepidoptera: Insights into flower-visitor interactions.

PubMed

Kinoshita, Michiyo; Stewart, Finlay J; Ômura, Hisashi

2017-04-01

As most work on flower foraging focuses on bees, studying Lepidoptera can offer fresh perspectives on how sensory capabilities shape the interaction between flowers and insects. Through a combination of innate preferences and learning, many Lepidoptera persistently visit particular flower species. Butterflies tend to rely on their highly developed sense of colour to locate rewarding flowers, while moths have evolved sophisticated olfactory systems towards the same end. However, these modalities can interact in complex ways; for instance, butterflies' colour preference can shift depending on olfactory context. The mechanisms by which such cross-modal interaction occurs are poorly understood, but the mushroom bodies appear to play a central role. Because of the diversity seen within Lepidoptera in terms of their sensory capabilities and the nature of their relationships with flowers, they represent a fruitful avenue for comparative studies to shed light on the co-evolution of flowers and flower-visiting insects. © 2017 WILEY Periodicals, Inc.

Tulipa gesneriana and Lilium longiflorum PEBP Genes and Their Putative Roles in Flowering Time Control.

PubMed

Leeggangers, Hendrika A C F; Rosilio-Brami, Tamar; Bigas-Nadal, Judit; Rubin, Noam; van Dijk, Aalt D J; Nunez de Caceres Gonzalez, Francisco F; Saadon-Shitrit, Shani; Nijveen, Harm; Hilhorst, Henk W M; Immink, Richard G H; Zaccai, Michele

2018-01-01

Floral induction in Tulipa gesneriana and Lilium longiflorum is triggered by contrasting temperature conditions, high and low temperature, respectively. In Arabidopsis, the floral integrator FLOWERING LOCUS T (FT), a member of the PEBP (phosphatidyl ethanolamine-binding protein) gene family, is a key player in flowering time control. In this study, one PEBP gene was identified and characterized in lily (LlFT) and three PEBP genes were isolated from tulip (TgFT1, TgFT2 and TgFT3). Overexpression of these genes in Arabidopsis thaliana resulted in an early flowering phenotype for LlFT and TgFT2, but a late flowering phenotype for TgFT1 and TgFT3. Overexpression of LlFT in L. longiflorum also resulted in an early flowering phenotype, confirming its proposed role as a flowering time-controlling gene. The tulip PEBP genes TgFT2 and TgFT3 have a similar expression pattern in tulip, but show opposite effects on the timing of flowering in Arabidopsis. Therefore, the difference between these two proteins was further investigated by interchanging amino acids thought to be important for the FT function. This resulted in the conversion of phenotypes in Arabidopsis upon overexpressing the substituted TgFT2 and TgFT3 genes, revealing the importance of these interchanged amino acid residues. Based on all obtained results, we hypothesize that LlFT is involved in creating meristem competence to flowering-related cues in lily, and TgFT2 is considered to act as a florigen involved in the floral induction in tulip. The function of TgFT3 remains unclear, but, based on our observations and phylogenetic analysis, we propose a bulb-specific function for this gene. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

[Functional saponins in tea flower (flower buds of Camellia sinensis): gastroprotective and hypoglycemic effects of floratheasaponins and qualitative and quantitative analysis using HPLC].

PubMed

Yoshikawa, Masayuki; Wang, Tao; Sugimoto, Sachiko; Nakamura, Seikou; Nagatomo, Akifumi; Matsuda, Hisashi; Harima, Shoichi

2008-01-01

As a part of our characterization studies on the bioactive saponin constituents of tea flowers (Camellia sinensis, flower buds), the methanolic extract and 1-butanol-soluble portion (the saponin fraction) from the flower buds were found to exhibit potent inhibitory effects on ethanol- and indomethacin-induced gastric mucosal lesions in rats and on serum glucose elevation in sucrose-loaded rats. Among the constituents of the 1-butanol-soluble portion, floratheasaponins A, B, and C showed gastroprotective and hypoglycemic activities. Furthermore, we have developed qualitative and quantitative methods using HPLC for the principle saponins, floratheasaponins A-F, in tea flowers, which were previously found to show antiallergic and antiobesity effects. Using those methods, the saponin composition of Indian tea flowers were found to be similar to those of Chinese (Anhui) but not of Japanese tea flowers. On the other hand, it was found that the floratheasaponin contents in tea flowers varied markedly during the blooming period, and they were abundant at half-bloom. Additionally, the contents of caffeine in the tea flowers were examined using HPLC.

Gravitropism in cut flower stalks of snapdragon

NASA Astrophysics Data System (ADS)

Philosoph-Hadas, S.; Friedman, H.; Meir, S.; Berkovitz-SimanTov, R.; Rosenberger, I.; Halevy, A. H.; Kaufman, P. B.; Balk, P.; Woltering, E. J.

The negative gravitropic response of cut flower stalks is a complex multistep process that requires the participation of various cellular components acting in succession or in parallel. The process was particularly characterized in snapdragon (Antirrhinum majus L.) spikes with regard to (1) gravity stimulus perception associated with amyloplast reorientation; (2) stimulus transduction mediated through differential changes in the level, action and related genes of auxin and ethylene and their possible interaction; (3) stimulus response associated with differential growth leading to stalk curvature; (4) involvement of cytosolic calcium and actin cytoskeleton. Results show that the gravity-induced amyloplast reorientation, differential over-expression of two early auxin responsive genes and asymmetrical distribution of free IAA are early events in the bending process. These precede the asymmetrical ethylene production and differential stem growth, which was derived from initial shrinkage of the upper stem side and a subsequent elongation of the lower stem side. Results obtained with various calcium- and cytoskeleton-related agents indicate that cytosolic calcium and actin filaments may play essential roles in gravitropism-related processes of cut flower stalks. Therefore, modulators of these two physiological mediators may serve as means for controlling any undesired gravitropic bending.

Cretaceous flowers of Nymphaeaceae and implications for complex insect entrapment pollination mechanisms in early angiosperms.

PubMed

Gandolfo, M A; Nixon, K C; Crepet, W L

2004-05-25

Based on recent molecular systematics studies, the water lily lineage (Nymphaeales) provides an important key to understanding ancestral angiosperm morphology and is of considerable interest in the context of angiosperm origins. Therefore, the fossil record of Nymphaeales potentially provides evidence on both the timing and nature of diversification of one of the earliest clades of flowering plants. Recent fossil evidence of Turonian age (approximately 90 million years B.P.) includes fossil flowers with characters that, upon rigorous analysis, firmly place them within Nymphaeaceae. Unequivocally the oldest floral record of the Nymphaeales, these fossils are closely related to the modern Nymphaealean genera Victoria (the giant Amazon water lily) and Euryale. Although the fossils are much smaller than their modern relatives, the precise and dramatic correspondence between the fossil floral morphology and that of modern Victoria flowers suggests that beetle entrapment pollination was present in the earliest part of the Late Cretaceous.

Use of transcriptome sequencing to understand the pistillate flowering in hickory (Carya cathayensis Sarg.).

PubMed

Huang, You-Jun; Liu, Li-Li; Huang, Jian-Qin; Wang, Zheng-Jia; Chen, Fang-Fang; Zhang, Qi-Xiang; Zheng, Bing-Song; Chen, Ming

2013-10-10

Different from herbaceous plants, the woody plants undergo a long-period vegetative stage to achieve floral transition. They then turn into seasonal plants, flowering annually. In this study, a preliminary model of gene regulations for seasonal pistillate flowering in hickory (Carya cathayensis) was proposed. The genome-wide dynamic transcriptome was characterized via the joint-approach of RNA sequencing and microarray analysis. Differential transcript abundance analysis uncovered the dynamic transcript abundance patterns of flowering correlated genes and their major functions based on Gene Ontology (GO) analysis. To explore pistillate flowering mechanism in hickory, a comprehensive flowering gene regulatory network based on Arabidopsis thaliana was constructed by additional literature mining. A total of 114 putative flowering or floral genes including 31 with differential transcript abundance were identified in hickory. The locations, functions and dynamic transcript abundances were analyzed in the gene regulatory networks. A genome-wide co-expression network for the putative flowering or floral genes shows three flowering regulatory modules corresponding to response to light abiotic stimulus, cold stress, and reproductive development process, respectively. Totally 27 potential flowering or floral genes were recruited which are meaningful to understand the hickory specific seasonal flowering mechanism better. Flowering event of pistillate flower bud in hickory is triggered by several pathways synchronously including the photoperiod, autonomous, vernalization, gibberellin, and sucrose pathway. Totally 27 potential flowering or floral genes were recruited from the genome-wide co-expression network function module analysis. Moreover, the analysis provides a potential FLC-like gene based vernalization pathway and an 'AC' model for pistillate flower development in hickory. This work provides an available framework for pistillate flower development in hickory, which is

Use of transcriptome sequencing to understand the pistillate flowering in hickory (Carya cathayensis Sarg.)

PubMed Central

2013-01-01

Background Different from herbaceous plants, the woody plants undergo a long-period vegetative stage to achieve floral transition. They then turn into seasonal plants, flowering annually. In this study, a preliminary model of gene regulations for seasonal pistillate flowering in hickory (Carya cathayensis) was proposed. The genome-wide dynamic transcriptome was characterized via the joint-approach of RNA sequencing and microarray analysis. Results Differential transcript abundance analysis uncovered the dynamic transcript abundance patterns of flowering correlated genes and their major functions based on Gene Ontology (GO) analysis. To explore pistillate flowering mechanism in hickory, a comprehensive flowering gene regulatory network based on Arabidopsis thaliana was constructed by additional literature mining. A total of 114 putative flowering or floral genes including 31 with differential transcript abundance were identified in hickory. The locations, functions and dynamic transcript abundances were analyzed in the gene regulatory networks. A genome-wide co-expression network for the putative flowering or floral genes shows three flowering regulatory modules corresponding to response to light abiotic stimulus, cold stress, and reproductive development process, respectively. Totally 27 potential flowering or floral genes were recruited which are meaningful to understand the hickory specific seasonal flowering mechanism better. Conclusions Flowering event of pistillate flower bud in hickory is triggered by several pathways synchronously including the photoperiod, autonomous, vernalization, gibberellin, and sucrose pathway. Totally 27 potential flowering or floral genes were recruited from the genome-wide co-expression network function module analysis. Moreover, the analysis provides a potential FLC-like gene based vernalization pathway and an 'AC’ model for pistillate flower development in hickory. This work provides an available framework for pistillate flower

Impacts of climate change on spring flower tourism in Beijing, China

NASA Astrophysics Data System (ADS)

Wang, Huanjiong

2016-04-01

The beauty of blooming flowers causes spring to be one of the most picturesque and pleasant seasons in which to travel. However, the blooming time of plant species are very sensitive to small changes in climate. Therefore, recent climate change may shift flowering time and, as a result, may affect timing of spring tourism for tourists. In order to prove this assumption, we gathered data of first flowering date and end of flowering date (1963-2014) for 49 common ornamental plants in Beijing, China. In addition, we used the number of messages (2010-2014) posted on Sina Weibo (one of the most popular microblogs sites in China, in use by well over 30% of internet users, with a market penetration similar to the United States' Twitter) to indicate the tourist numbers of five scenic spots in Beijing. These spots are most famous places for seeing spring flowers, including the Summer Palace, Yuyuantan Park, Beijing Botanical Garden, Jingshan Park, Dadu City Wall Relics Park. The results showed that the number of species in flower starts to increase in early spring and peaks in middle spring, and then begins to decrease from late spring. The date when the number of species in flower peaks can be defined as best date of spring flower tourism, because on this day people can see blooming flowers of most plant species. The best date of spring flower tourism varied from March 31 to May 1 among years with a mean of April 20. At above scenic spots characterized by the beauty of blooming flowers, tourist numbers also had a peak value during spring. Furthermore, peak time of tourist numbers derived from Weibo varied among different years and was related to best date of spring flower tour derived from phenological data. This suggests that the time of spring outing for tourists is remarkably attracted by flowering phenology. From 1963 to 2014, the best date of spring flower tour became earlier at a rate of 1.6 days decade-1, but the duration for spring flower tour (defined as width at

Eastern White Pine Flowering in Response to Spray Application of Gibbrellin A4/7 or ProconeTM

Treesearch

Paula M. Pijut

2002-01-01

Eastern white pine (Pinus strobus L.) is an important forestry species in the northeastern and midwestern United States and in eastern Canada. Induction of early and reliable flowering and cone production will shorten the breeding cycle and aid in the development of genetically improved white pine. The objective of this study was to determine if a...

Promoter difference of LcFT1 is a leading cause of natural variation of flowering timing in different litchi cultivars (Litchi chinensis Sonn.).

PubMed

Ding, Feng; Zhang, Shuwei; Chen, Houbin; Su, Zuanxian; Zhang, Rong; Xiao, Qiusheng; Li, Hongli

2015-12-01

Litchi (Litchi chinensis) is an important subtropical evergreen fruit crop with high commercial value due to its high nutritional values and favorable tastes. However, irregular bearing attributed to unstable flowering is a major ongoing problem for litchi producers. There is a need to better understand the genetic and molecular mechanisms underlying the reproductive process in litchi. In a previous study, our laboratory had analyzed the transcriptome of litchi leaves before and after low-temperature treatment with RNA-seq technology. Herein, we demonstrated that litchi flowering was induced by low-temperature and identified two FLOWERING LOCUS T (FT) homologue genes named LcFT1 and LcFT2, respectively. We found that low-temperature could only induce LcFT1 expression in leaves, but could not induce LcFT2 expression. Heterologous expression of LcFT1 in transgenic tobacco and Arabidopsis plants induced their precocious flowering. These results indicate that LcFT1 plays a pivotal role in litchi floral induction by low-temperature. In addition, we found that two types of LcFT1 promoter existed in different litchi cultivars. The LcFT1 promoters in the early-flowering cultivars belonged to one type whereas LcFT1 promoters in the late-flowering belonged to another one. LcFT1 promoter in the early-flowering cultivars was more sensitive to low-temperature than that of the late-flowering cultivars was, which may be caused by the different cis-acting elements, including MYC, MYB, ABRE, and WRKY cis-acting elements, which were found to be present in the LcFT1 promoter sequences of the early-flowering cultivars. This difference may be responsible for the different requirements of low-temperature for floral induction in the early- and late-flowering cultivars of litchi. Taken together, the difference in LcFT1 promoter sequences may be one of the leading cause for the natural variation of flowering timing in different litchi cultivars. Our study has provided valuable genetic

Phylogeny determines flower size-dependent sex allocation at flowering in a hermaphroditic family.

PubMed

Teixido, A L; Guzmán, B; Staggemeier, V G; Valladares, F

2017-11-01

In animal-pollinated hermaphroditic plants, optimal floral allocation determines relative investment into sexes, which is ultimately dependent on flower size. Larger flowers disproportionally increase maleness whereas smaller and less rewarding flowers favour female function. Although floral traits are considered strongly conserved, phylogenetic relationships in the interspecific patterns of resource allocation to floral sex remain overlooked. We investigated these patterns in Cistaceae, a hermaphroditic family. We reconstructed phylogenetic relationships among Cistaceae species and quantified phylogenetic signal for flower size, dry mass and nutrient allocation to floral structures in 23 Mediterranean species using Blomberg's K-statistic. Lastly, phylogenetically-controlled correlational and regression analyses were applied to examine flower size-based allometry in resource allocation to floral structures. Sepals received the highest dry mass allocation, followed by petals, whereas sexual structures increased nutrient allocation. Flower size and resource allocation to floral structures, except for carpels, showed a strong phylogenetic signal. Larger-flowered species allometrically allocated more resources to maleness, by increasing allocation to corollas and stamens. Our results suggest a major role of phylogeny in determining interspecific changes in flower size and subsequent floral sex allocation. This implies that flower size balances the male-female function over the evolutionary history of Cistaceae. While allometric resource investment in maleness is inherited across species diversification, allocation to the female function seems a labile trait that varies among closely related species that have diversified into different ecological niches. © 2017 German Botanical Society and The Royal Botanical Society of the Netherlands.

Functional Characterization of Phalaenopsis aphrodite Flowering Genes PaFT1 and PaFD

PubMed Central

Jang, Seonghoe; Choi, Sang-Chul; Li, Hsing-Yi; An, Gynheung; Schmelzer, Elmon

2015-01-01

We show that the key flowering regulators encoded by Phalaenopsis aphrodite FLOWERING LOCUS T1 (PaFT1) and PaFD share high sequence homologies to these from long-day flowering Arabidopsis and short-day flowering rice. Interestingly, PaFT1 is specifically up-regulated during flowering inductive cooling treatment but is not subjected to control by photoperiod in P. aphrodite. Phloem or shoot apex-specific expression of PaFT1 restores the late flowering of Arabidopsis ft mutants. Moreover, PaFT1 can suppress the delayed flowering caused by SHORT VEGATATIVE PHASE (SVP) overexpression as well as an active FRIGIDA (FRI) allele, indicating the functional conservation of flowering regulatory circuit in different plant species. PaFT1 promoter:GUS in Arabidopsis showed similar staining pattern to that of Arabidopsis FT in the leaves and guard cells but different in the shoot apex. A genomic clone or heat shock-inducible expression of PaFT1 is sufficient to the partial complementation of the ft mutants. Remarkably, ectopic PaFT1 expression also triggers precocious heading in rice. To further demonstrate the functional conservation of the flowering regulators, we show that PaFD, a bZIP transcription factor involved in flowering promotion, interacts with PaFT1, and PaFD partially complemented Arabidopsis fd mutants. Transgenic rice expressing PaFD also flowered early with increased expression of rice homologues of APETALA1 (AP1). Consistently, PaFT1 knock-down Phalaenopsis plants generated by virus-induced gene silencing exhibit delayed spiking. These studies suggest functional conservation of FT and FD genes, which may have evolved and integrated into distinct regulatory circuits in monopodial orchids, Arabidopsis and rice that promote flowering under their own inductive conditions. PMID:26317412

Development of sampling methods for the slash pine flower thrips Gnophothrips fuscus (Morgan), (Thysanoptera: Phlaeothripidae)

Treesearch

Carl W. Fatzinger; Wayne N. Dixen

1991-01-01

Slash pine flower thrips typically destroy about 24% of the flowers (cones) present in slash pine seed orchards. The seasonal distribution and abundance of slash pine flower thrips are being investigated and methods for sampling field populations of the insect are being evaluated for potential use in integrated pest management strategies. The efficacies of several...

Design a Hummingbird Flower.

ERIC Educational Resources Information Center

Bailey, Kim

2002-01-01

Presents an activity that engages students in designing and making an artificial flower adapted for pollination by hummingbirds. Students work in teams to design flowers that maximize the benefit from attracting hummingbirds. Examines characteristics of real flowers adapted to pollination by hummingbirds. (DLH)

Pollinator-mediated selection on flower color, flower scent and flower morphology of Hemerocallis: evidence from genotyping individual pollen grains on the stigma.

PubMed

Hirota, Shun K; Nitta, Kozue; Suyama, Yoshihisa; Kawakubo, Nobumitsu; Yasumoto, Akiko A; Yahara, Tetsukazu

2013-01-01

To trace the fate of individual pollen grains through pollination processes, we determined genotypes of single pollen grains deposited on Hemerocallis stigmas in an experimental mixed-species array. Hemerocallis fulva, pollinated by butterflies, has diurnal, reddish and unscented flowers, and H. citrina, pollinated by hawkmoths, has nocturnal, yellowish and sweet scent flowers. We observed pollinator visits to an experimental array of 24 H. fulva and 12 F2 hybrids between the two species (H. fulva and H. citrina) and collected stigmas after every trip bout of swallowtail butterflies or hawkmoths. We then measured selection by swallowtail butterflies or hawkmoths through male and female components of pollination success as determined by single pollen genotyping. As expected, swallowtail butterflies imposed selection on reddish color and weak scent: the number of outcross pollen grains acquired is a quadratic function of flower color with the maximum at reddish color, and the combined pollination success was maximal at weak scent (almost unrecognizable for human). This explains why H. fulva, with reddish flowers and no recognizable scent, is mainly pollinated by swallowtail butterflies. However, we found no evidence of hawkmoths-mediated selection on flower color or scent. Our findings do not support a hypothesis that yellow flower color and strong scent intensity, the distinctive floral characteristics of H. citrina, having evolved in adaptations to hawkmoths. We suggest that the key trait that triggers the evolution of nocturnal flowers is flowering time rather than flower color and scent.

Pollinator-Mediated Selection on Flower Color, Flower Scent and Flower Morphology of Hemerocallis: Evidence from Genotyping Individual Pollen Grains On the Stigma

PubMed Central

Hirota, Shun K.; Nitta, Kozue; Suyama, Yoshihisa; Kawakubo, Nobumitsu; Yasumoto, Akiko A.; Yahara, Tetsukazu

2013-01-01

To trace the fate of individual pollen grains through pollination processes, we determined genotypes of single pollen grains deposited on Hemerocallis stigmas in an experimental mixed-species array. Hemerocallis fulva, pollinated by butterflies, has diurnal, reddish and unscented flowers, and H. citrina, pollinated by hawkmoths, has nocturnal, yellowish and sweet scent flowers. We observed pollinator visits to an experimental array of 24 H. fulva and 12 F2 hybrids between the two species (H. fulva and H. citrina) and collected stigmas after every trip bout of swallowtail butterflies or hawkmoths. We then measured selection by swallowtail butterflies or hawkmoths through male and female components of pollination success as determined by single pollen genotyping. As expected, swallowtail butterflies imposed selection on reddish color and weak scent: the number of outcross pollen grains acquired is a quadratic function of flower color with the maximum at reddish color, and the combined pollination success was maximal at weak scent (almost unrecognizable for human). This explains why H. fulva, with reddish flowers and no recognizable scent, is mainly pollinated by swallowtail butterflies. However, we found no evidence of hawkmoths-mediated selection on flower color or scent. Our findings do not support a hypothesis that yellow flower color and strong scent intensity, the distinctive floral characteristics of H. citrina, having evolved in adaptations to hawkmoths. We suggest that the key trait that triggers the evolution of nocturnal flowers is flowering time rather than flower color and scent. PMID:24376890

Transcriptomic Analysis of Flower Blooming in Jasminum sambac through De Novo RNA Sequencing.

PubMed

Li, Yong-Hua; Zhang, Wei; Li, Yong

2015-06-10

Flower blooming is a critical and complicated plant developmental process in flowering plants. However, insufficient information is available about the complex network that regulates flower blooming in Jasminum sambac. In this study, we used the RNA-Seq platform to analyze the molecular regulation of flower blooming in J. sambac by comparing the transcript profiles at two flower developmental stages: budding and blooming. A total of 4577 differentially-expressed genes (DEGs) were identified between the two floral stages. The Gene Ontology and the Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses revealed that the DEGs in the "oxidation-reduction process", "extracellular region", "steroid biosynthesis", "glycosphingolipid biosynthesis", "plant hormone signal transduction" and "pentose and glucuronate interconversions" might be associated with flower development. A total of 103 and 92 unigenes exhibited sequence similarities to the known flower development and floral scent genes from other plants. Among these unigenes, five flower development and 19 floral scent unigenes exhibited at least four-fold differences in expression between the two stages. Our results provide abundant genetic resources for studying the flower blooming mechanisms and molecular breeding of J. sambac.

Testing the influence of gravity on flower symmetry in five Saxifraga species.

PubMed

Koethe, Sebastian; Bloemer, Judith; Lunau, Klaus

2017-04-01

Flower symmetry is considered a species-specific trait and is categorized in asymmetry, actinomorphic symmetry, bisymmetry and zygomorphic symmetry. Here we report on the intra-individual variation of flower symmetry in the genus Saxifraga and the influence of light, gravity and intrinsic factors on the development of flower symmetry. We tested five species-Saxifraga cuneifolia, Saxifraga imparilis, Saxifraga rotundifolia, Saxifraga stolonifera and Saxifraga umbrosa-concerning six flower parameters-angles between petals, petal length, petal pigmentation, angular position of carpels, movement of stamens and (only for S. imparilis and S. stolonifera) the length of the two lower elongated petals in regard to their position towards the stem. Specimens of all species were tested on a vertical clinostat as a gravity compensator, on a horizontal clinostat as a light incidence compensator and on a stationary control. The results show that the angle of incident light has no apparent impact on flower symmetry, whereas gravity affects the angular position of petals in S. cuneifolia and S. umbrosa and the petal colouration in S. rotundifolia. In S. cuneifolia and S. umbrosa, the absence of directional gravity resulted in the development of actinomorphic flowers, whereas the corresponding control flowers were zygomorphic. The development of flowers in S. rotundifolia was not altered by this treatment. The length of the two elongated petals in S. stolonifera and S. imparilis was not affected by gravity, but rather was determined by position of the flower within the inflorescence and resulted in asymmetrical flowers.

Testing the influence of gravity on flower symmetry in five Saxifraga species

NASA Astrophysics Data System (ADS)

Koethe, Sebastian; Bloemer, Judith; Lunau, Klaus

2017-04-01

Flower symmetry is considered a species-specific trait and is categorized in asymmetry, actinomorphic symmetry, bisymmetry and zygomorphic symmetry. Here we report on the intra-individual variation of flower symmetry in the genus Saxifraga and the influence of light, gravity and intrinsic factors on the development of flower symmetry. We tested five species— Saxifraga cuneifolia, Saxifraga imparilis, Saxifraga rotundifolia, Saxifraga stolonifera and Saxifraga umbrosa—concerning six flower parameters—angles between petals, petal length, petal pigmentation, angular position of carpels, movement of stamens and (only for S. imparilis and S. stolonifera) the length of the two lower elongated petals in regard to their position towards the stem. Specimens of all species were tested on a vertical clinostat as a gravity compensator, on a horizontal clinostat as a light incidence compensator and on a stationary control. The results show that the angle of incident light has no apparent impact on flower symmetry, whereas gravity affects the angular position of petals in S. cuneifolia and S. umbrosa and the petal colouration in S. rotundifolia. In S. cuneifolia and S. umbrosa, the absence of directional gravity resulted in the development of actinomorphic flowers, whereas the corresponding control flowers were zygomorphic. The development of flowers in S. rotundifolia was not altered by this treatment. The length of the two elongated petals in S. stolonifera and S. imparilis was not affected by gravity, but rather was determined by position of the flower within the inflorescence and resulted in asymmetrical flowers.

Evolvability of flower geometry: Convergence in pollinator-driven morphological evolution of flowers.

PubMed

Woźniak, Natalia Joanna; Sicard, Adrien

2018-07-01

Flowers represent a key innovation during plant evolution. Driven by reproductive optimization, evolution of flower morphology has been central in boosting species diversification. In most cases, this has happened through specialized interactions with animal pollinators and subsequent reduction of gene flow between specialized morphs. While radiation has led to an enormous variability in flower forms and sizes, recurrent evolutionary patterns can be observed. Here, we discuss the targets of selection involved in major trends of pollinator-driven flower evolution. We review recent findings on their adaptive values, developmental grounds and genetic bases, in an attempt to better understand the repeated nature of pollinator-driven flower evolution. This analysis highlights how structural innovation can provide flexibility in phenotypic evolution, adaptation and speciation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Reduction in the critical dark length for flower induction during aging in the short-day plant Pharbitis nil var. Kidachi.

PubMed

Hasegawa, Hiroshi; Yamada, Mizuki; Iwase, Yuiko; Wada, Kaede C; Takeno, Kiyotoshi

2010-12-01

The stress-sensitive short-day plant Pharbitis nil var. Kidachi flowers under a 16-h light and 8-h dark regime and non-stress conditions when grown for long periods of time. Such flowering was found to occur from the third week, and the floral buds were formed from the eighth node of the main stem. When young plants were grafted onto aged plants, the scions were induced to flower early. This flower induction by grafting was more effective when older plants were used as rootstocks. Grafting experiments using a single leaf as a donor revealed that younger leaves are more responsive to flower induction, suggesting that this age-mediated flowering response is not induced by aging or senescence of individual leaves. Rather, the plant may obtain the ability to flower as the whole plant ages. Flowering does not occur under continuous light conditions. A night break given in the 8-h dark period inhibits flowering. These results suggest that 8-h dark conditions, which are normally considered to be long-day conditions, actually correspond to short-day conditions for this plant. The 8-h dark conditions caused early flowering more efficiently in older plants. The critical dark length determined by a single treatment was 12 h in 0-week-old plants and was reduced to 6 h in 2- and 4-week-old plants. These results suggest that the critical dark length becomes shorter when plants get older. The expression of PnFT1 and PnFT2, orthologs of the flowering gene flowering locus T, was analyzed by reverse transcription-polymerase chain reaction revealing that the expression of PnFT at the end of dark period is correlated with flowering.

Flower constancy in insect pollinators

PubMed Central

Ratnieks, Francis L.W.

2011-01-01

As first noted by Aristotle in honeybee workers, many insect pollinators show a preference to visit flowers of just one species during a foraging trip. This “flower constancy” probably benefits plants, because pollen is more likely to be deposited on conspecific stigmas. But it is less clear why insects should ignore rewarding alternative flowers. Many researchers have argued that flower constancy is caused by constraints imposed by insect nervous systems rather than because flower constancy is itself an efficient foraging method. We argue that this view is unsatisfactory because it both fails to explain why foragers flexibly adjust the degree of flower constancy and does not explain why foragers of closely related species show different degrees of constancy. While limitations of the nervous system exist and are likely to influence flower constancy to some degree, the observed behavioural flexibility suggests that flower constancy is a successful foraging strategy given the insect’s own information about different foraging options. PMID:22446521

Effects of small-scale clustering of flowers on pollinator foraging behaviour and flower visitation rate.

PubMed

Akter, Asma; Biella, Paolo; Klecka, Jan

2017-01-01

Plants often grow in clusters of various sizes and have a variable number of flowers per inflorescence. This small-scale spatial clustering affects insect foraging strategies and plant reproductive success. In our study, we aimed to determine how visitation rate and foraging behaviour of pollinators depend on the number of flowers per plant and on the size of clusters of multiple plants using Dracocephalum moldavica (Lamiaceae) as a target species. We measured flower visitation rate by observations of insects visiting single plants and clusters of plants with different numbers of flowers. Detailed data on foraging behaviour within clusters of different sizes were gathered for honeybees, Apis mellifera, the most abundant visitor of Dracocephalum in the experiments. We found that the total number of flower visitors increased with the increasing number of flowers on individual plants and in larger clusters, but less then proportionally. Although individual honeybees visited more flowers in larger clusters, they visited a smaller proportion of flowers, as has been previously observed. Consequently, visitation rate per flower and unit time peaked in clusters with an intermediate number of flowers. These patterns do not conform to expectations based on optimal foraging theory and the ideal free distribution model. We attribute this discrepancy to incomplete information about the distribution of resources. Detailed observations and video recordings of individual honeybees also showed that the number of flowers had no effect on handling time of flowers by honeybees. We evaluated the implications of these patterns for insect foraging biology and plant reproduction.

Effects of small-scale clustering of flowers on pollinator foraging behaviour and flower visitation rate

PubMed Central

2017-01-01

Plants often grow in clusters of various sizes and have a variable number of flowers per inflorescence. This small-scale spatial clustering affects insect foraging strategies and plant reproductive success. In our study, we aimed to determine how visitation rate and foraging behaviour of pollinators depend on the number of flowers per plant and on the size of clusters of multiple plants using Dracocephalum moldavica (Lamiaceae) as a target species. We measured flower visitation rate by observations of insects visiting single plants and clusters of plants with different numbers of flowers. Detailed data on foraging behaviour within clusters of different sizes were gathered for honeybees, Apis mellifera, the most abundant visitor of Dracocephalum in the experiments. We found that the total number of flower visitors increased with the increasing number of flowers on individual plants and in larger clusters, but less then proportionally. Although individual honeybees visited more flowers in larger clusters, they visited a smaller proportion of flowers, as has been previously observed. Consequently, visitation rate per flower and unit time peaked in clusters with an intermediate number of flowers. These patterns do not conform to expectations based on optimal foraging theory and the ideal free distribution model. We attribute this discrepancy to incomplete information about the distribution of resources. Detailed observations and video recordings of individual honeybees also showed that the number of flowers had no effect on handling time of flowers by honeybees. We evaluated the implications of these patterns for insect foraging biology and plant reproduction. PMID:29136042

Spatial and temporal transcriptome changes occurring during flower opening and senescence of the ephemeral hibiscus flower, Hibiscus rosa-sinensis.

PubMed

Trivellini, Alice; Cocetta, Giacomo; Hunter, Donald A; Vernieri, Paolo; Ferrante, Antonio

2016-10-01

Flowers are complex systems whose vegetative and sexual structures initiate and die in a synchronous manner. The rapidity of this process varies widely in flowers, with some lasting for months while others such as Hibiscus rosa-sinensis survive for only a day. The genetic regulation underlying these differences is unclear. To identify key genes and pathways that coordinate floral organ senescence of ephemeral flowers, we identified transcripts in H. rosa-sinensis floral organs by 454 sequencing. During development, 2053 transcripts increased and 2135 decreased significantly in abundance. The senescence of the flower was associated with increased abundance of many hydrolytic genes, including aspartic and cysteine proteases, vacuolar processing enzymes, and nucleases. Pathway analysis suggested that transcripts altering significantly in abundance were enriched in functions related to cell wall-, aquaporin-, light/circadian clock-, autophagy-, and calcium-related genes. Finding enrichment in light/circadian clock-related genes fits well with the observation that hibiscus floral development is highly synchronized with light and the hypothesis that ageing/senescence of the flower is orchestrated by a molecular clock. Further study of these genes will provide novel insight into how the molecular clock is able to regulate the timing of programmed cell death in tissues. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

The Flavonoid Pathway Regulates the Petal Colors of Cotton Flower

PubMed Central

Tan, Jiafu; Wang, Maojun; Tu, Lili; Nie, Yichun; Lin, Yongjun; Zhang, Xianlong

2013-01-01

Although biochemists and geneticists have studied the cotton flower for more than one century, little is known about the molecular mechanisms underlying the dramatic color change that occurs during its short developmental life following blooming. Through the analysis of world cotton germplasms, we found that all of the flowers underwent color changes post-anthesis, but there is a diverse array of petal colors among cotton species, with cream, yellow and red colors dominating the color scheme. Genetic and biochemical analyses indicated that both the original cream and red colors and the color changes post-anthesis were related to flavonoid content. The anthocyanin content and the expression of biosynthesis genes were both increased from blooming to one day post-anthesis (DPA) when the flower was withering and undergoing abscission. Our results indicated that the color changes and flavonoid biosynthesis of cotton flowers were precisely controlled and genetically regulated. In addition, flavonol synthase (FLS) genes involved in flavonol biosynthesis showed specific expression at 11 am when the flowers were fully opened. The anthocyanidin reductase (ANR) genes, which are responsible for proanthocyanidins biosynthesis, showed the highest expression at 6 pm on 0 DPA, when the flowers were withered. Light showed primary, moderate and little effects on flavonol, anthocyanin and proanthocyanidin biosynthesis, respectively. Flavonol biosynthesis was in response to light exposure, while anthocyanin biosynthesis was involved in flower color changes. Further expression analysis of flavonoid genes in flowers of wild type and a flavanone 3-hydroxylase (F3H) silenced line showed that the development of cotton flower color was controlled by a complex interaction between genes and light. These results present novel information regarding flavonoids metabolism and flower development. PMID:23951318

Flower development of Phalaenopsis orchid involves functionally divergent SEPALLATA-like genes

PubMed Central

Pan, Zhao-Jun; Chen, You-Yi; Du, Jian-Syun; Chen, Yun-Yu; Chung, Mei-Chu; Tsai, Wen-Chieh; Wang, Chun-Neng; Chen, Hong-Hwa

2014-01-01

The Phalaenopsis orchid produces complex flowers that are commercially valuable, which has promoted the study of its flower development. E-class MADS-box genes, SEPALLATA (SEP), combined with B-, C- and D-class MADS-box genes, are involved in various aspects of plant development, such as floral meristem determination, organ identity, fruit maturation, seed formation and plant architecture. Four SEP-like genes were cloned from Phalaenopsis orchid, and the duplicated PeSEPs were grouped into PeSEP1/3 and PeSEP2/4. All PeSEPs were expressed in all floral organs. PeSEP2 expression was detectable in vegetative tissues. The study of protein–protein interactions suggested that PeSEPs may form higher order complexes with the B-, C-, D-class and AGAMOUS LIKE6-related MADS-box proteins to determine floral organ identity. The tepal became a leaf-like organ when PeSEP3 was silenced by virus-induced silencing, with alterations in epidermis identity and contents of anthocyanin and chlorophyll. Silencing of PeSEP2 had minor effects on the floral phenotype. Silencing of the E-class genes PeSEP2 and PeSEP3 resulted in the downregulation of B-class PeMADS2-6 genes, which indicates an association of PeSEP functions and B-class gene expression. These findings reveal the important roles of PeSEP in Phalaenopsis floral organ formation throughout the developmental process by the formation of various multiple protein complexes. PMID:24571782

Reproductive isolation between Zaluzianskya species: the influence of volatiles and flower orientation on hawkmoth foraging choices.

PubMed

Campbell, Diane R; Jürgens, Andreas; Johnson, Steven D

2016-04-01

Floral trait differences between related species may play a key role in reproductive isolation imposed by pollinators. Volatile emissions can influence pollinator choice, but how they act in combination with traits such as flower orientation is rarely studied. We compared flower-opening patterns, morphology, colour, orientation and volatile emissions for two closely related species of Zaluzianskya and their natural hybrids. Hawkmoth pollinators were tested for preference between flowers of the two species, and between flowers with manipulations of volatiles or orientation. Flowers of Z. natalensis and Z. microsiphon open at night and day, respectively, but they overlap during early evening, when hawkmoths showed a strong preference for Z. natalensis. The species have similar flower size and colour, but Z. natalensis emits more floral volatiles in the evening and presents flowers vertically face-up as opposed to horizontally in Z. microsiphon, whereas natural hybrids are intermediate. Adding methyl benzoate and linalool to flowers of Z. microsiphon did not increase hawkmoth attraction, but re-orientation of flowers to face vertically increased attraction when scent cues were present, whereas re-orientation of Z. natalensis flowers to face horizontally decreased attraction. This study highlights the importance of flower orientation in imposing reproductive isolation. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

Molecular cloning and characterization of a gene regulating flowering time from Alfalfa (Medicago sativa L.).

PubMed

Zhang, Tiejun; Chao, Yuehui; Kang, Junmei; Ding, Wang; Yang, Qingchuan

2013-07-01

Genes that regulate flowering time play crucial roles in plant development and biomass formation. Based on the cDNA sequence of Medicago truncatula (accession no. AY690425), the LFY gene of alfalfa was cloned. Sequence similarity analysis revealed high homology with FLO/LFY family genes of other plants. When fused to the green fluorescent protein, MsLFY protein was localized in the nucleus of onion (Allium cepa L.) epidermal cells. The RT-qPCR analysis of MsLFY expression patterns showed that the expression of MsLFY gene was at a low level in roots, stems, leaves and pods, and the expression level in floral buds was the highest. The expression of MsLFY was induced by GA3 and long photoperiod. Plant expression vector was constructed and transformed into Arabidopsis by the agrobacterium-mediated methods. PCR amplification with the transgenic Arabidopsis genome DNA indicated that MsLFY gene had integrated in Arabidopsis genome. Overexpression of MsLFY specifically caused early flowering under long day conditions compared with non-transgenic plants. These results indicated MsLFY played roles in promoting flowering time.

Insect Seed Predators in Erythrina falcata (Fabaceae): Identification of Predatory Species and Ecological Consequences of Asynchronous Flowering.

PubMed

Pereira, C M; Moura, M O; Da-Silva, P R

2014-06-01

Seed predation by insects exerts negative effects on plant reproduction by limiting the supply of seeds and preventing germination. Seed predators of the family Fabaceae are usually generalists, which increases the rate of predation. One strategy to minimize seed predation, developed by plants from temperate regions, is "escape in time," i.e., flowering before or after the peak of predation. For tropical species, few studies have investigated the strategies used by plants to minimize seed predation. Here, using Erythrina falcata, a tropical species of Fabaceae, we test three main hypotheses: (i) escape in time is a mechanism used by E. falcata to minimize seed predation, (ii) the predators of E. falcata seeds are generalists, and (iii) the biometric variables of the pods can influence seed predation. In order to test these hypotheses, we determined the flowering time of E. falcata, rate of seed predation, the predators insects, and biometric variables of the pods. The analyzed trees were grouped into three classes: "early," "peak," and "late" flowering. The average seed predation rates on trees in the early and late classes were 65% and 50%, respectively, and in the peak class, 80%; thus, our first hypothesis can be accepted. Three species of Lepidoptera and two of Coleoptera were found preying on E. falcata seeds. These species were observed to be generalist predators; thus, our second hypothesis can be accepted. The biometric variables of the pods cannot influence seed predation rate. The ecological consequences of asynchronous flowering on plants and insects are discussed.

What flowers do we like? The influence of shape and color on the rating of flower beauty.

PubMed

Hůla, Martin; Flegr, Jaroslav

2016-01-01

There is no doubt that people find flowers beautiful. Surprisingly, we know very little about the actual properties which make flowers so appealing to humans. Although the evolutionary aesthetics provides some theories concerning generally preferred flower traits, empirical evidence is largely missing. In this study, we used an online survey in which residents of the Czech Republic (n = 2006) rated the perceived beauty of 52 flower stimuli of diverse shapes and colors. Colored flowers were preferred over their uncolored versions. When controlling for flower shape, we found an unequal preference for different flower colors, blue being the most and yellow the least preferred. In the overall assessment of beauty, shape was more important than color. Prototypical flowers, i.e., radially symmetrical flowers with low complexity, were rated as the most beautiful. We also found a positive effect of sharp flower contours and blue color on the overall rating of flower beauty. The results may serve as a basis for further studies in some areas of the people-plant interaction research.

What flowers do we like? The influence of shape and color on the rating of flower beauty

PubMed Central

Flegr, Jaroslav

2016-01-01

There is no doubt that people find flowers beautiful. Surprisingly, we know very little about the actual properties which make flowers so appealing to humans. Although the evolutionary aesthetics provides some theories concerning generally preferred flower traits, empirical evidence is largely missing. In this study, we used an online survey in which residents of the Czech Republic (n = 2006) rated the perceived beauty of 52 flower stimuli of diverse shapes and colors. Colored flowers were preferred over their uncolored versions. When controlling for flower shape, we found an unequal preference for different flower colors, blue being the most and yellow the least preferred. In the overall assessment of beauty, shape was more important than color. Prototypical flowers, i.e., radially symmetrical flowers with low complexity, were rated as the most beautiful. We also found a positive effect of sharp flower contours and blue color on the overall rating of flower beauty. The results may serve as a basis for further studies in some areas of the people-plant interaction research. PMID:27330863

Flowering phenology and its implications for management of big-leaf mahogany Swietenia macrophylla in Brazilian Amazonia.

PubMed

Grogan, James; Loveless, Marilyn D

2013-11-01

Flowering phenology is a crucial determinant of reproductive success and offspring genetic diversity in plants. We measure the flowering phenology of big-leaf mahogany (Swietenia macrophylla, Meliaceae), a widely distributed neotropical tree, and explore how disturbance from logging impacts its reproductive biology. We use a crown scoring system to estimate the timing and duration of population-level flowering at three forest sites in the Brazilian Amazon over a five-year period. We combine this information with data on population structure and spatial distribution to consider the implications of logging for population flowering patterns and reproductive success. Mahogany trees as small as 14 cm diam flowered, but only trees > 30 cm diam flowered annually or supra-annually. Mean observed flowering periods by focal trees ranged from 18-34 d, and trees flowered sequentially during 3-4 mo beginning in the dry season. Focal trees demonstrated significant interannual correlation in flowering order. Estimated population-level flowering schedules resembled that of the focal trees, with temporal isolation between early and late flowering trees. At the principal study site, conventional logging practices eliminated 87% of mahogany trees > 30 cm diam and an estimated 94% of annual pre-logging floral effort. Consistent interannual patterns of sequential flowering among trees create incompletely isolated subpopulations, constraining pollen flow. After harvests, surviving subcommercial trees will have fewer, more distant, and smaller potential partners, with probable consequences for post-logging regeneration. These results have important implications for the sustainability of harvesting systems for tropical timber species.

Deciphering the Role of POLYCOMB REPRESSIVE COMPLEX1 Variants in Regulating the Acquisition of Flowering Competence in Arabidopsis1

PubMed Central

Picó, Sara; Merini, Wiam

2015-01-01

Polycomb group (PcG) proteins play important roles in regulating developmental phase transitions in plants; however, little is known about the role of the PcG machinery in regulating the transition from juvenile to adult phase. Here, we show that Arabidopsis (Arabidopsis thaliana) B lymphoma Moloney murine leukemia virus insertion region1 homolog (BMI1) POLYCOMB REPRESSIVE COMPLEX1 (PRC1) components participate in the repression of microRNA156 (miR156). Loss of AtBMI1 function leads to the up-regulation of the primary transcript of MIR156A and MIR156C at the time the levels of miR156 should decline, resulting in an extended juvenile phase and delayed flowering. Conversely, the PRC1 component EMBRYONIC FLOWER (EMF1) participates in the regulation of SQUAMOSA PROMOTER-BINDING PROTEIN-LIKE and MIR172 genes. Accordingly, plants impaired in EMF1 function displayed misexpression of these genes early in development, which contributes to a CONSTANS-independent up-regulation of FLOWERING LOCUS T (FT) leading to the earliest flowering phenotype described in Arabidopsis. Our findings show how the different regulatory roles of two functional PRC1 variants coordinate the acquisition of flowering competence and help to reach the threshold of FT necessary to flower. Furthermore, we show how two central regulatory mechanisms, such as PcG and microRNA, assemble to achieve a developmental outcome. PMID:25897002

Transcriptomics analysis of the flowering regulatory genes involved in the herbicide resistance of Asia minor bluegrass (Polypogon fugax).

PubMed

Zhou, Fengyan; Zhang, Yong; Tang, Wei; Wang, Mei; Gao, Tongchun

2017-12-06

Asia minor bluegrass (Polypogon fugax, P. fugax), a weed that is both distributed across China and associated with winter crops, has evolved resistance to acetyl-CoA carboxylase (ACCase) herbicides, but the resistance mechanism remains unclear. The goal of this study was to analyze the transcriptome between resistant and sensitive populations of P. fugax at the flowering stage. Populations resistant and susceptible to clodinafop-propargyl showed distinct transcriptome profiles. A total of 206,041 unigenes were identified; 165,901 unique sequences were annotated using BLASTX alignment databases. Among them, 5904 unigenes were classified into 58 transcription factor families. Nine families were related to the regulation of plant growth and development and to stress responses. Twelve unigenes were differentially expressed between the clodinafop-propargyl-sensitive and clodinafop-propargyl-resistant populations at the early flowering stage; among those unigenes, three belonged to the ABI3VP1, BHLH, and GRAS families, while the remaining nine belonged to the MADS family. Compared with the clodinafop-propargyl-sensitive plants, the resistant plants exhibited different expression pattern of these 12 unigenes. This study identified differentially expressed unigenes related to ACCase-resistant P. fugax and thus provides a genomic resource for understanding the molecular basis of early flowering.

Discussion on Comprehensive Utilization Value of Scutellaria Baicalensis Flower

NASA Astrophysics Data System (ADS)

Song, Yagang; Miao, Mingsan

2018-01-01

The chemical constituents of Scutellaria baicalensis flower are flavonoids, volatile oils and melanin, It has anti-tumor, anti-inflammatory, antioxidant, anti angiogenic and antithrombotic pharmacological effects, and it has the effect of clearing away heat and relieving lung fire. Scutellaria baicalensis flower is rich in resources, cheap, easy to obtain, accurate effect, With the prevention and treatment of a variety of diseases. In this paper, the ancient application, chemical constituents, pharmacological actions and comprehensive utilization of Scutellaria baicalensis flower were reviewed, The purpose of this study was to explore the value of its development and utilization, so as to provide reference for the comprehensive utilization of Scutellaria baicalensis flower.

Effects of plant size, temperature, and light intensity on flowering of Phalaenopsis hybrids in Mediterranean greenhouses.

PubMed

Paradiso, Roberta; De Pascale, Stefania

2014-01-01

Mediterranean greenhouses for cultivation of Phalaenopsis orchids reproduce the warm, humid, and shaded environment of tropical underbrush. Heating represents the highest production cost, due to the high thermal requirements and the long unproductive phase of juvenility, in which plants attain the critical size for flowering. Our researches aimed to investigate the effect of plant size, temperature, and light intensity, during the phase of flower induction, on flowering of modern genotypes selected for Mediterranean greenhouses. Three experiments were carried out to compare (i) plant size: reduced size versus size considered optimal for flowering (hybrids "Sogo Yukidian," "Chain Xen Diamond," and "Pinlong"); (ii) temperature: moderate reduction of temperature versus standard thermal regime (hybrid "Premium"); (iii) light intensity: supplemental lighting versus reference light intensity (hybrid "Premium"). The premature exposure of plants to the inductive treatment delayed the beginning of flowering and reduced the flower stem quality, in all the tested hybrids. In "Premium," the lower temperature did not affect flowering earliness and commercial quality of flower stems compared to the standard regime, whereas it promoted stem branching. In the same hybrid, supplemental lighting anticipated flowering and promoted the emission of the second stem and the stem branching, compared to the reference light regime.

Flowering responses of insect-pollinated plants to elevated CO{sub 2} levels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cushman, J.H.; Koch, G.W.; Chiariello, N.R.

1995-06-01

Elevated atmospheric CO{sub 2} concentrations have been predicted or shown to substantially influence plants, communities and ecosystems in a variety of ways. Here, we examined the effects of elevated CO{sub 2} levels on the timing and magnitude of flowering for two insect-pollinated annual plant species in a serpentine grassland. We focused on Lasthenia californica and Linanthus parviflorus and addressed three questions: (1) Do elevated CO{sub 2} levels influence flowering phenologies and is this species specific? (2) Do elevated CO{sub 2} levels affect flower production and is this due to altered numbers of individuals, flowers per plant, or both? and (3)more » Are effects on flowering due to elevated CO{sub 2} levels per se or changes in environmental conditions associated with methods used to manipulate CO{sub 2} levels? To address these questions, we used the ecosystem experiment at Stanford University`s Jasper Ridge Biological Preserve (San Mateo Co., CA). This system consists of 20 open-topped chambers - half receiving ambient CO{sub 2} (360 ppm) and half receiving elevated CO{sub 2} (720 ppm) - and 10 untreated plots serving as chamber controls. Results from the 1994 season demonstrated that there were species-specific responses to elevated CO{sub 2} levels and the field chambers. For Lasthenia californica, elevated CO{sub 2} per se did not affect relative abundance, inflorescence production, or phenology, but chambers did significantly increase inflorescence production and extend the duration of flowering. For Linanthus parviflorus, elevated CO{sub 2} levels significantly increased relative abundance and flower production, and extended the flowering period slightly, while the chambers significantly decreased flower production early in the season and increased it later in the season.« less

Tropical flowering phenologies

NASA Astrophysics Data System (ADS)

Wright, S. J.

2016-12-01

Most tropical plants flower synchronously at species-specific times. This holds at the geographic equator where day length is constant and at the meteorological equator where temperature is virtually aseasonal. Thus, the well-studied environmental cues for flowering at higher latitudes can be irrelevant in the tropics where they are replaced by an abundance of hypotheses. Low and high temperatures, drought and rain, day length, daily solar irradiance, and seasonal changes in solar insolation at the forest canopy or at the top of the atmosphere have all been hypothesized to act as environmental cues for tropical flowering. This abundance of hypotheses has been confronted by a paucity of data, precluding rejection of even one hypothesis. I will use new long-term data sets from Barro Colorado Island (BCI), Panama (9°N, 79°W) and a model selection framework to begin the winnowing. The data extend from 1987 to the present and include more than 250,000 flower records obtained in 1,515 weekly censuses of 200 passive traps and standard meteorological variables obtained just above the forest canopy. The model selection framework was used to evaluate every proximate cue hypothesized to control tropical flowering times for the 55 tree and liana species best represented in the data. Hypotheses concerning seasonal variation in day length, temperature, rainfall and photosynthetically active radiation (PAR) best matched the data for five, zero, seven and 32 species, respectively. Many species previously believed to respond to seasonal changes in moisture availability are actually sensitive to seasonal variation in cloud cover and PAR. BCI lies on the meteorological equator, thus it is unsurprising that temperature variation is not a viable proximate cue. The flowering phenology of the remaining 11 species could not be explained by any of the hypothesized proximate cues. Solutions to the environmental control of tropical flowering times remain to be discovered.

Insects on flowers

PubMed Central

Wardhaugh, Carl W.; Stork, Nigel E.; Edwards, Will; Grimbacher, Peter S.

2013-01-01

Insect biodiversity peaks in tropical rainforest environments where a large but as yet unknown proportion of species are found in the canopy. While there has been a proliferation of insect biodiversity research undertaken in the rainforest canopy, most studies focus solely on insects that inhabit the foliage. In a recent paper, we examined the distribution of canopy insects across five microhabitats (mature leaves, new leaves, flowers, fruit and suspended dead wood) in an Australian tropical rainforest, showing that the density (per dry weight gram of microhabitat) of insects on flowers were ten to ten thousand times higher than on the leaves. Flowers also supported a much higher number of species than expected based on their contribution to total forest biomass. Elsewhere we show that most of these beetle species were specialized to flowers with little overlap in species composition between different canopy microhabitats. Here we expand our discussion of the implications of our results with respect to specialization and the generation of insect biodiversity in the rainforest canopy. Lastly, we identify future directions for research into the biodiversity and specialization of flower-visitors in complex tropical rainforests. PMID:23802039

Flower power: tree flowering phenology as a settlement cue for migrating birds.

PubMed

McGrath, Laura J; van Riper, Charles; Fontaine, Joseph J

2009-01-01

1. Neotropical migrant birds show a clear preference for stopover habitats with ample food supplies; yet, the proximate cues underlying these decisions remain unclear. 2. For insectivorous migrants, cues associated with vegetative phenology (e.g. flowering, leaf flush, and leaf loss) may reliably predict the availability of herbivorous arthropods. Here we examined whether migrants use the phenology of five tree species to choose stopover locations, and whether phenology accurately predicts food availability. 3. Using a combination of experimental and observational evidence, we show migrant populations closely track tree phenology, particularly the flowering phenology of honey mesquite (Prosopis glandulosa), and preferentially forage in trees with more flowers. Furthermore, the flowering phenology of honey mesquite reliably predicts overall arthropod abundance as well as the arthropods preferred by migrants for food. 4. Together, these results suggest that honey mesquite flowering phenology is an important cue used by migrants to assess food availability quickly and reliably, while in transit during spring migration.

Flower power: Tree flowering phenology as a settlement cue for migrating birds

USGS Publications Warehouse

McGrath, L.J.; van Riper, Charles; Fontaine, J.J.

2009-01-01

1. Neotropical migrant birds show a clear preference for stopover habitats with ample food supplies; yet, the proximate cues underlying these decisions remain unclear. 2. For insectivorous migrants, cues associated with vegetative phenology (e.g. flowering, leaf flush, and leaf loss) may reliably predict the availability of herbivorous arthropods. Here we examined whether migrants use the phenology of five tree species to choose stopover locations, and whether phenology accurately predicts food availability. 3. Using a combination of experimental and observational evidence, we show migrant populations closely track tree phenology, particularly the flowering phenology of honey mesquite (Prosopis glandulosa), and preferentially forage in trees with more flowers. Furthermore, the flowering phenology of honey mesquite reliably predicts overall arthropod abundance as well as the arthropods preferred by migrants for food. 4. Together, these results suggest that honey mesquite flowering phenology is an important cue used by migrants to assess food availability quickly and reliably, while in transit during spring migration. ?? 2008 The Authors.

An apple MYB transcription factor, MdMYB3, is involved in regulation of anthocyanin biosynthesis and flower development.

PubMed

Vimolmangkang, Sornkanok; Han, Yuepeng; Wei, Guochao; Korban, Schuyler S

2013-11-07

TF is involved in regulation of flower development. This study has identified a novel MYB transcription factor in the apple genome. This TF, designated as MdMYB3, is involved in transcriptional activation of several flavonoid pathway genes. Moreover, this TF not only regulates the accumulation of anthocyanin in the skin of apple fruits, but it is also involved in the regulation of flower development, particularly that of pistil development.

Choctaw Culture Early Education Activities.

ERIC Educational Resources Information Center

Brescia, William, Ed.; Reeves, Carolyn, Ed.; Skinner, Linda, Ed.

An effort to better prepare Choctaw youngsters for kindergarten, the Choctaw Culture Early Education Program developed a resource of 58 activities adapted to meet the needs of Choctaw 3- and 4-year olds. The activities are divided into four sections pertaining to getting started, relating to five project publications (How the Flowers Came to Be,…

The effect of flower position on variation and covariation in floral traits in a wild hermaphrodite plant

PubMed Central

2010-01-01

Background Floral traits within plants can vary with flower position or flowering time. Within an inflorescence, sexual allocation of early produced basal flowers is often female-biased while later produced distal flowers are male-biased. Such temporal adjustment of floral resource has been considered one of the potential advantages of modularity (regarding a flower as a module) in hermaphrodites. However, flowers are under constraints of independent evolution of a given trait. To understand flower diversification within inflorescences, here we examine variation and covariation in floral traits within racemes at the individual and the maternal family level respectively in an alpine herb Aconitum gymnandrum (Ranunculaceae). Results We found that floral traits varied significantly with flower position and among families, and position effects were family-specific. Most of the variance of floral traits was among individuals rather than among flowers within individuals or among families. Significant phenotypic correlations between traits were not affected by position, indicating trait integration under shared developmental regulation. In contrast, positive family-mean correlations in floral traits declined gradually from basal to distal flowers (nine significant correlations among floral traits in basal flowers and only three in distal flowers), showing position-specificity. Therefore, the pattern and magnitude of genetic correlations decreased with flower position. Conclusions This finding on covariation pattern in floral reproductive structures within racemes has not been revealed before, providing insights into temporal variation and position effects in floral traits within plants and the potential advantages of modularity in hermaphrodites. PMID:20482889

The effect of flower position on variation and covariation in floral traits in a wild hermaphrodite plant.

PubMed

Zhao, Zhi-Gang; Du, Guo-Zhen; Huang, Shuang-Quan

2010-05-20

Floral traits within plants can vary with flower position or flowering time. Within an inflorescence, sexual allocation of early produced basal flowers is often female-biased while later produced distal flowers are male-biased. Such temporal adjustment of floral resource has been considered one of the potential advantages of modularity (regarding a flower as a module) in hermaphrodites. However, flowers are under constraints of independent evolution of a given trait. To understand flower diversification within inflorescences, here we examine variation and covariation in floral traits within racemes at the individual and the maternal family level respectively in an alpine herb Aconitum gymnandrum (Ranunculaceae). We found that floral traits varied significantly with flower position and among families, and position effects were family-specific. Most of the variance of floral traits was among individuals rather than among flowers within individuals or among families. Significant phenotypic correlations between traits were not affected by position, indicating trait integration under shared developmental regulation. In contrast, positive family-mean correlations in floral traits declined gradually from basal to distal flowers (nine significant correlations among floral traits in basal flowers and only three in distal flowers), showing position-specificity. Therefore, the pattern and magnitude of genetic correlations decreased with flower position. This finding on covariation pattern in floral reproductive structures within racemes has not been revealed before, providing insights into temporal variation and position effects in floral traits within plants and the potential advantages of modularity in hermaphrodites.

Nonlinear flowering responses to climate: are species approaching their limits of phenological change?

PubMed

Iler, Amy M; Høye, Toke T; Inouye, David W; Schmidt, Niels M

2013-08-19

Many alpine and subalpine plant species exhibit phenological advancements in association with earlier snowmelt. While the phenology of some plant species does not advance beyond a threshold snowmelt date, the prevalence of such threshold phenological responses within plant communities is largely unknown. We therefore examined the shape of flowering phenology responses (linear versus nonlinear) to climate using two long-term datasets from plant communities in snow-dominated environments: Gothic, CO, USA (1974-2011) and Zackenberg, Greenland (1996-2011). For a total of 64 species, we determined whether a linear or nonlinear regression model best explained interannual variation in flowering phenology in response to increasing temperatures and advancing snowmelt dates. The most common nonlinear trend was for species to flower earlier as snowmelt advanced, with either no change or a slower rate of change when snowmelt was early (average 20% of cases). By contrast, some species advanced their flowering at a faster rate over the warmest temperatures relative to cooler temperatures (average 5% of cases). Thus, some species seem to be approaching their limits of phenological change in response to snowmelt but not temperature. Such phenological thresholds could either be a result of minimum springtime photoperiod cues for flowering or a slower rate of adaptive change in flowering time relative to changing climatic conditions.

[Natural history of flowers and gravity].

PubMed

Yamashita, Masamichi; Tomita-Yokotani, Kaori; Nakamura, Teruko

2004-06-01

Many flowers have coevolved with their pollinator animals. Gravity has been one of selection pressure for the evolution of flowers. Gravity rules morphology and other features of flowers in many aspects. Pair matching between the flower and its specific pollinator is one of factors that determine the fitness of both sides. Evolution of flower morphology and its molecular basis are reviewed briefly. Anemophilous flowers are also under the influence of gravity. Shape and other features of entomophilous flowers have been highly diversed. Gravitropic response and its mechanism are summarized. Recent findings on gravitropism and phototropism of pistils and stamens are presented in this article.

Deciphering the Role of POLYCOMB REPRESSIVE COMPLEX1 Variants in Regulating the Acquisition of Flowering Competence in Arabidopsis.

PubMed

Picó, Sara; Ortiz-Marchena, M Isabel; Merini, Wiam; Calonje, Myriam

2015-08-01

Polycomb group (PcG) proteins play important roles in regulating developmental phase transitions in plants; however, little is known about the role of the PcG machinery in regulating the transition from juvenile to adult phase. Here, we show that Arabidopsis (Arabidopsis thaliana) B lymphoma Moloney murine leukemia virus insertion region1 homolog (BMI1) POLYCOMB REPRESSIVE COMPLEX1 (PRC1) components participate in the repression of microRNA156 (miR156). Loss of AtBMI1 function leads to the up-regulation of the primary transcript of MIR156A and MIR156C at the time the levels of miR156 should decline, resulting in an extended juvenile phase and delayed flowering. Conversely, the PRC1 component EMBRYONIC FLOWER (EMF1) participates in the regulation of SQUAMOSA PROMOTER-BINDING PROTEIN-LIKE and MIR172 genes. Accordingly, plants impaired in EMF1 function displayed misexpression of these genes early in development, which contributes to a CONSTANS-independent up-regulation of FLOWERING LOCUS T (FT) leading to the earliest flowering phenotype described in Arabidopsis. Our findings show how the different regulatory roles of two functional PRC1 variants coordinate the acquisition of flowering competence and help to reach the threshold of FT necessary to flower. Furthermore, we show how two central regulatory mechanisms, such as PcG and microRNA, assemble to achieve a developmental outcome. © 2015 American Society of Plant Biologists. All Rights Reserved.

Transcriptome Analysis of Flower Sex Differentiation in Jatropha curcas L. Using RNA Sequencing.

PubMed

Xu, Gang; Huang, Jian; Yang, Yong; Yao, Yin-an

2016-01-01

Jatropha curcas is thought to be a promising biofuel material, but its yield is restricted by a low ratio of instaminate/staminate flowers (1/10-1/30). Furthermore, valuable information about flower sex differentiation in this plant is scarce. To explore the mechanism of this process in J. curcas, transcriptome profiling of flower development was carried out, and certain genes related with sex differentiation were obtained through digital gene expression analysis of flower buds from different phases of floral development. After Illumina sequencing and clustering, 57,962 unigenes were identified. A total of 47,423 unigenes were annotated, with 85 being related to carpel and stamen differentiation, 126 involved in carpel and stamen development, and 592 functioning in the later development stage for the maturation of staminate or instaminate flowers. Annotation of these genes provided comprehensive information regarding the sex differentiation of flowers, including the signaling system, hormone biosynthesis and regulation, transcription regulation and ubiquitin-mediated proteolysis. A further expression pattern analysis of 15 sex-related genes using quantitative real-time PCR revealed that gibberellin-regulated protein 4-like protein and AMP-activated protein kinase are associated with stamen differentiation, whereas auxin response factor 6-like protein, AGAMOUS-like 20 protein, CLAVATA1, RING-H2 finger protein ATL3J, auxin-induced protein 22D, and r2r3-myb transcription factor contribute to embryo sac development in the instaminate flower. Cytokinin oxidase, Unigene28, auxin repressed-like protein ARP1, gibberellin receptor protein GID1 and auxin-induced protein X10A are involved in both stages mentioned above. In addition to its function in the differentiation and development of the stamens, the gibberellin signaling pathway also functions in embryo sac development for the instaminate flower. The auxin signaling pathway also participates in both stamen development

Transcriptome Analysis of Flower Sex Differentiation in Jatropha curcas L. Using RNA Sequencing

PubMed Central

Xu, Gang; Huang, Jian; Yang, Yong; Yao, Yin-an

2016-01-01

Background Jatropha curcas is thought to be a promising biofuel material, but its yield is restricted by a low ratio of instaminate / staminate flowers (1/10-1/30). Furthermore, valuable information about flower sex differentiation in this plant is scarce. To explore the mechanism of this process in J. curcas, transcriptome profiling of flower development was carried out, and certain genes related with sex differentiation were obtained through digital gene expression analysis of flower buds from different phases of floral development. Results After Illumina sequencing and clustering, 57,962 unigenes were identified. A total of 47,423 unigenes were annotated, with 85 being related to carpel and stamen differentiation, 126 involved in carpel and stamen development, and 592 functioning in the later development stage for the maturation of staminate or instaminate flowers. Annotation of these genes provided comprehensive information regarding the sex differentiation of flowers, including the signaling system, hormone biosynthesis and regulation, transcription regulation and ubiquitin-mediated proteolysis. A further expression pattern analysis of 15 sex-related genes using quantitative real-time PCR revealed that gibberellin-regulated protein 4-like protein and AMP-activated protein kinase are associated with stamen differentiation, whereas auxin response factor 6-like protein, AGAMOUS-like 20 protein, CLAVATA1, RING-H2 finger protein ATL3J, auxin-induced protein 22D, and r2r3-myb transcription factor contribute to embryo sac development in the instaminate flower. Cytokinin oxidase, Unigene28, auxin repressed-like protein ARP1, gibberellin receptor protein GID1 and auxin-induced protein X10A are involved in both stages mentioned above. In addition to its function in the differentiation and development of the stamens, the gibberellin signaling pathway also functions in embryo sac development for the instaminate flower. The auxin signaling pathway also participates in both

The bouquet of grapevine (Vitis vinifera L. cv. Cabernet Sauvignon) flowers arises from the biosynthesis of sesquiterpene volatiles in pollen grains

PubMed Central

Martin, Diane M.; Toub, Omid; Chiang, Angela; Lo, Bernard C.; Ohse, Sebastian; Lund, Steven T.; Bohlmann, Jörg

2009-01-01

Terpenoid volatiles are important information molecules that enable pollinators to locate flowers and may protect reproductive tissues against pathogens or herbivores. Inflorescences of grapevine (Vitis vinifera L.) are composed of tiny green flowers that produce an abundance of sesquiterpenoid volatiles. We demonstrate that male flower parts of grapevines are responsible for sesquiterpenoid floral scent formation. We describe temporal and spatial patterns of biosynthesis and release of floral volatiles throughout the blooming of V. vinifera L. cv. Cabernet Sauvignon. The biosynthesis of sesquiterpene volatiles, which are emitted with a light-dependent diurnal pattern early in the morning at prebloom and bloom, is localized to anthers and, more specifically, within the developing pollen grains. Valencene synthase (VvValCS) enzyme activity, which produces the major sesquiterpene volatiles of grapevine flowers, is present in anthers. VvValCS transcripts are most abundant in flowers at prebloom stages. Western blot analysis identified VvValCS protein in anthers, and in situ immunolabeling located VvValCS protein in pollen grains during bloom. Histochemical staining, as well as immunolabeling analysis by fluorescent microscopy and transmission electron microscopy, indicated that VvValCS localizes close to lipid bodies within the maturing microspore. PMID:19359488

Molecular mechanisms underlying the diverse array of petal colors in chrysanthemum flowers.

PubMed

Ohmiya, Akemi

2018-01-01

Chrysanthemum ( Chrysanthemum morifolium Ramat.) is one of the most important floricultural crops in the world. Although the origin of modern chrysanthemum cultivars is uncertain, several species belonging to the family Asteraceae are considered to have been integrated during the long history of breeding. The flower color of ancestral species is limited to yellow, pink, and white, and is derived from carotenoids, anthocyanins, and the absence of both pigments, respectively. A wide range of flower colors, including purplish-red, orange, red, and dark red, has been developed by increasing the range of pigment content or the combination of both pigments. Recently, green-flowered cultivars containing chlorophylls in their ray petals have been produced, and have gained popularity. In addition, blue/violet flowers have been developed using a transgenic approach. Flower color is an important trait that influences the commercial value of chrysanthemum cultivars. Understanding the molecular mechanisms that regulate flower pigmentation may provide important implications for the rationale manipulation of flower color. This review describes the pigment composition, genetics, and molecular basis of ray petal color formation in chrysanthemum cultivars.

Identification and Functional Analysis of Flowering Related microRNAs in Common Wild Rice (Oryza rufipogon Griff.)

PubMed Central

Dong, Yibo; Yuan, Qianhua; Wang, Feng; Li, Weimin; Jiang, Ying; Jia, Shirong; Pei, XinWu

2013-01-01

Background MicroRNAs (miRNAs) is a class of non-coding RNAs involved in post- transcriptional control of gene expression, via degradation and/or translational inhibition. Six-hundred sixty-one rice miRNAs are known that are important in plant development. However, flowering-related miRNAs have not been characterized in Oryza rufipogon Griff. It was approved by supervision department of Guangdong wild rice protection. We analyzed flowering-related miRNAs in O. rufipogon using high-throughput sequencing (deep sequencing) to understand the changes that occurred during rice domestication, and to elucidate their functions in flowering. Results Three O. rufipogon sRNA libraries, two vegetative stage (CWR-V1 and CWR-V2) and one flowering stage (CWR-F2) were sequenced using Illumina deep sequencing. A total of 20,156,098, 21,531,511 and 20,995,942 high quality sRNA reads were obtained from CWR-V1, CWR-V2 and CWR-F2, respectively, of which 3,448,185, 4,265,048 and 2,833,527 reads matched known miRNAs. We identified 512 known rice miRNAs in 214 miRNA families and predicted 290 new miRNAs. Targeted functional annotation, GO and KEGG pathway analyses predicted that 187 miRNAs regulate expression of flowering-related genes. Differential expression analysis of flowering-related miRNAs showed that: expression of 95 miRNAs varied significantly between the libraries, 66 are flowering-related miRNAs, such as oru-miR97, oru-miR117, oru-miR135, oru-miR137, et al. 17 are early-flowering -related miRNAs, including osa-miR160f, osa-miR164d, osa-miR167d, osa-miR169a, osa-miR172b, oru-miR4, et al., induced during the floral transition. Real-time PCR revealed the same expression patterns as deep sequencing. miRNAs targets were confirmed for cleavage by 5′-RACE in vivo, and were negatively regulated by miRNAs. Conclusions This is the first investigation of flowering miRNAs in wild rice. The result indicates that variation in miRNAs occurred during rice domestication and lays a foundation

Identification and functional analysis of flowering related microRNAs in common wild rice (Oryza rufipogon Griff.).

PubMed

Chen, Zongxiang; Li, Fuli; Yang, Songnan; Dong, Yibo; Yuan, Qianhua; Wang, Feng; Li, Weimin; Jiang, Ying; Jia, Shirong; Pei, Xinwu

2013-01-01

MicroRNAs (miRNAs) is a class of non-coding RNAs involved in post- transcriptional control of gene expression, via degradation and/or translational inhibition. Six-hundred sixty-one rice miRNAs are known that are important in plant development. However, flowering-related miRNAs have not been characterized in Oryza rufipogon Griff. It was approved by supervision department of Guangdong wild rice protection. We analyzed flowering-related miRNAs in O. rufipogon using high-throughput sequencing (deep sequencing) to understand the changes that occurred during rice domestication, and to elucidate their functions in flowering. Three O. rufipogon sRNA libraries, two vegetative stage (CWR-V1 and CWR-V2) and one flowering stage (CWR-F2) were sequenced using Illumina deep sequencing. A total of 20,156,098, 21,531,511 and 20,995,942 high quality sRNA reads were obtained from CWR-V1, CWR-V2 and CWR-F2, respectively, of which 3,448,185, 4,265,048 and 2,833,527 reads matched known miRNAs. We identified 512 known rice miRNAs in 214 miRNA families and predicted 290 new miRNAs. Targeted functional annotation, GO and KEGG pathway analyses predicted that 187 miRNAs regulate expression of flowering-related genes. Differential expression analysis of flowering-related miRNAs showed that: expression of 95 miRNAs varied significantly between the libraries, 66 are flowering-related miRNAs, such as oru-miR97, oru-miR117, oru-miR135, oru-miR137, et al. 17 are early-flowering -related miRNAs, including osa-miR160f, osa-miR164d, osa-miR167d, osa-miR169a, osa-miR172b, oru-miR4, et al., induced during the floral transition. Real-time PCR revealed the same expression patterns as deep sequencing. miRNAs targets were confirmed for cleavage by 5'-RACE in vivo, and were negatively regulated by miRNAs. This is the first investigation of flowering miRNAs in wild rice. The result indicates that variation in miRNAs occurred during rice domestication and lays a foundation for further study of phase change

Endophytic and pathogenic fungi of developing cranberry ovaries from flower to mature fruit: diversity and succession

USDA-ARS?s Scientific Manuscript database

Culturable fungal population diversity and succession were investigated in developing cranberry ovaries of fruit rot-resistant and rot-susceptible cranberry selections, from flower through mature fruit. Fungi were recovered in culture from 1185 of 1338 ovary tissues collected from June to September,...

Genetic Enhancer Analysis Reveals that FLORAL ORGAN NUMBER2 and OsMADS3 Co-operatively Regulate Maintenance and Determinacy of the Flower Meristem in Rice.

PubMed

Yasui, Yukiko; Tanaka, Wakana; Sakamoto, Tomoaki; Kurata, Tetsuya; Hirano, Hiro-Yuki

2017-05-01

Meristems such as the shoot apical meristem and flower meristem (FM) act as a reservoir of stem cells, which reproduce themselves and supply daughter cells for the differentiation of lateral organs. In Oryza sativa (rice), the FLORAL ORGAN NUMBER2 (FON2) gene, which is similar to Arabidopsis CLAVATA3, is involved in meristem maintenance. In fon2 mutants, the numbers of floral organs are increased due to an enlargement of the FM. To identify new factors regulating meristem maintenance in rice, we performed a genetic screening of mutants that enhanced the fon2 mutation, and found a mutant line (2B-424) in which pistil number was dramatically increased. By using a map-based approach and next-generation sequencing, we found that the line 2B-424 had a complete loss-of-function mutation (a large deletion) in OsMADS3, a class C MADS-box gene that is known to be involved in stamen specification. Disruption of OsMADS3 in the fon2 mutant by CRISPR-Cas9 (clustered regularly interspaced short palindromic repeats-CRISPR-associated protein 9) technology caused a flower phenotype similar to that of 2B-424, confirming that the gene responsible for enhancement of fon2 was OsMADS3. Morphological analysis showed that the fon2 and osmads3 mutations synergistically affected pistil development and FM determinacy. We also found that whorl 3 was duplicated in mature flowers and the FM was enlarged at an early developmental stage in severe osmads3 single mutants. These findings suggest that OsMADS3 is involved not only in FM determinacy in late flower development but also in FM activity in early flower development. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

POLYGALACTURONASE INVOLVED IN EXPANSION1 functions in cell elongation and flower development in Arabidopsis.

PubMed

Xiao, Chaowen; Somerville, Chris; Anderson, Charles T

2014-03-01

Pectins are acidic carbohydrates that comprise a significant fraction of the primary walls of eudicotyledonous plant cells. They influence wall porosity and extensibility, thus controlling cell and organ growth during plant development. The regulated degradation of pectins is required for many cell separation events in plants, but the role of pectin degradation in cell expansion is poorly defined. Using an activation tag screen designed to isolate genes involved in wall expansion, we identified a gene encoding a putative polygalacturonase that, when overexpressed, resulted in enhanced hypocotyl elongation in etiolated Arabidopsis thaliana seedlings. We named this gene POLYGALACTURONASE INVOLVED IN EXPANSION1 (PGX1). Plants lacking PGX1 display reduced hypocotyl elongation that is complemented by transgenic PGX1 expression. PGX1 is expressed in expanding tissues throughout development, including seedlings, roots, leaves, and flowers. PGX1-GFP (green fluorescent protein) localizes to the apoplast, and heterologously expressed PGX1 displays in vitro polygalacturonase activity, supporting a function for this protein in apoplastic pectin degradation. Plants either overexpressing or lacking PGX1 display alterations in total polygalacturonase activity, pectin molecular mass, and wall composition and also display higher proportions of flowers with extra petals, suggesting PGX1's involvement in floral organ patterning. These results reveal new roles for polygalacturonases in plant development.

Molecular and geographic evolutionary support for the essential role of GIGANTEAa in soybean domestication of flowering time.

PubMed

Wang, Yan; Gu, Yongzhe; Gao, Huihui; Qiu, Lijuan; Chang, Ruzhen; Chen, Shouyi; He, Chaoying

2016-04-12

Flowering time is a domestication trait of Glycine max and varies in soybeans, yet, a gene for flowering time variation has not been associated with soybean domestication. GIGANTEA (GI) is a major gene involved in the control of flowering time in Arabidopsis, although three GI homologs complicate this model in the soybean genome. In the present work, we revealed that the geographic evolution of the GIGANTEAa (GIa) haplotypes in G. max (GmGIa) and Glycine soja (GsGIa). Three GIa haplotypes (H1, H2, and H3) were found among cultivated soybeans and their wild relatives, yet an additional 44 diverse haplotypes were observed in wild soybeans. H1 had a premature stop codon in the 10(th) exon, whereas the other haplotypes encoded full-length GIa protein isoforms. In both wild-type and cultivated soybeans, H2 was present in the Southern region of China, and H3 was restricted to areas near the Northeast region of China. H1 was genetically derived from H2, and it was dominant and widely distributed among cultivated soybeans, whereas in wild populations, the ortholog of this domesticated haplotype H1 was only found in Yellow River basin with a low frequency. Moreover, this mutated GIa haplotype significantly correlated with early flowering. We further determined that the differences in gene expression of the three GmGIa haplotypes were not correlated to flowering time variations in cultivated soybeans. However, only the truncated GmGIa H1 could partially rescue gi-2 Arabidopsis from delayed flowering in transgenic plants, whereas both GmGIa H2 and H3 haplotypes could significantly repress flowering in transgenic Arabidopsis with a wild-type background. Thus, GmGIa haplotype diversification may have contributed to flowering time adaptation that facilitated the radiation of domesticated soybeans. In light of the evolution of the GIa gene, soybean domestication history for an early flowering phenotype is discussed.

Pistil Starch Reserves at Anthesis Correlate with Final Flower Fate in Avocado (Persea americana)

PubMed Central

Alcaraz, María Librada; Hormaza, José Ignacio; Rodrigo, Javier

2013-01-01

A common observation in different plant species is a massive abscission of flowers and fruitlets even after adequate pollination, but little is known as to the reason for this drop. Previous research has shown the importance of nutritive reserves accumulated in the flower on fertilization success and initial fruit development but direct evidence has been elusive. Avocado (Persea americana) is an extreme case of a species with a very low fruit to flower ratio. In this work, the implications of starch content in the avocado flower on the subsequent fruit set are explored. Firstly, starch content in individual ovaries was analysed from two populations of flowers with a different fruit set capacity showing that the flowers from the population that resulted in a higher percentage of fruit set contained significantly more starch. Secondly, in a different set of flowers, the style of each flower was excised one day after pollination, once the pollen tubes had reached the base of the style, and individually fixed for starch content analysis under the microscope once the fate of its corresponding ovary (that remained in the tree) was known. A high variability in starch content in the style was found among flowers, with some flowers having starch content up to 1,000 times higher than others, and the flowers that successfully developed into fruits presented significantly higher starch content in the style at anthesis than those that abscised. The relationship between starch content in the ovary and the capacity of set of the flower together with the correlation found between the starch content in the style and the fate of the ovary support the hypothesis that the carbohydrate reserves accumulated in the flower at anthesis are related to subsequent abscission or retention of the developing fruit. PMID:24167627

Pistil starch reserves at anthesis correlate with final flower fate in avocado (Persea americana).

PubMed

Alcaraz, María Librada; Hormaza, José Ignacio; Rodrigo, Javier

2013-01-01

A common observation in different plant species is a massive abscission of flowers and fruitlets even after adequate pollination, but little is known as to the reason for this drop. Previous research has shown the importance of nutritive reserves accumulated in the flower on fertilization success and initial fruit development but direct evidence has been elusive. Avocado (Persea americana) is an extreme case of a species with a very low fruit to flower ratio. In this work, the implications of starch content in the avocado flower on the subsequent fruit set are explored. Firstly, starch content in individual ovaries was analysed from two populations of flowers with a different fruit set capacity showing that the flowers from the population that resulted in a higher percentage of fruit set contained significantly more starch. Secondly, in a different set of flowers, the style of each flower was excised one day after pollination, once the pollen tubes had reached the base of the style, and individually fixed for starch content analysis under the microscope once the fate of its corresponding ovary (that remained in the tree) was known. A high variability in starch content in the style was found among flowers, with some flowers having starch content up to 1,000 times higher than others, and the flowers that successfully developed into fruits presented significantly higher starch content in the style at anthesis than those that abscised. The relationship between starch content in the ovary and the capacity of set of the flower together with the correlation found between the starch content in the style and the fate of the ovary support the hypothesis that the carbohydrate reserves accumulated in the flower at anthesis are related to subsequent abscission or retention of the developing fruit.

Perpetual flowering in strawberry species

USDA-ARS?s Scientific Manuscript database

Studies have revealed genetic control of flowering patterns for seasonal flowering (SF) and perpetual flowering (PF) genotypes in the common garden strawberry, with associated links to gene homeologs in diploid alpine strawberry, F. vesca L. Within the genus Fragaria, 22 species and multiple subspec...

AINTEGUMENTA-LIKE genes have partly overlapping functions with AINTEGUMENTA but make distinct contributions to Arabidopsis thaliana flower development

PubMed Central

Krizek, Beth A.

2015-01-01

AINTEGUMENTA (ANT) is an important regulator of Arabidopsis flower development that has overlapping functions with the related AINTEGUMENTA-LIKE6 (AIL6) gene in floral organ initiation, identity specification, growth, and patterning. Two other AINTEGUMENTA-LIKE (AIL) genes, AIL5 and AIL7, are expressed in developing flowers in spatial domains that partly overlap with those of ANT. Here, it is shown that AIL5 and AIL7 also act in a partially redundant manner with ANT. The results demonstrate that AIL genes exhibit unequal genetic redundancy with roles for AIL5, AIL6, and AIL7 only revealed in the absence of ANT function. ant ail5 and ant ail7 double mutant flowers show alterations in floral organ positioning and growth, sepal fusion, and reductions in petal number. In ant ail5, petals are often replaced by filaments or dramatically reduced in size. ant ail7 double mutants produce increased numbers of carpels, which have defects in valve fusion and a loss of apical tissues. The distinct phenotypes of ant ail5, ant ail7 and the previously characterized ant ail6 indicate that AIL5, AIL6, and AIL7 make unique contributions to flower development. These distinct roles are also supported by genetic analyses of ant ail triple mutants. While ant ail5 ail6 triple mutants closely resemble ant ail6 double mutants, ant ail5 ail7 triple mutants exhibit more severe deviations from the wild type than either ant ail5 or ant ail7 double mutants. Furthermore, it is shown that AIL5, AIL6, and AIL7 act in a dose dependent manners in ant and other mutant backgrounds. PMID:25956884

Transcriptome analysis of Jatropha curcas L. flower buds responded to the paclobutrazol treatment.

PubMed

Seesangboon, Anupharb; Gruneck, Lucsame; Pokawattana, Tittinat; Eungwanichayapant, Prapassorn Damrongkool; Tovaranonte, Jantrararuk; Popluechai, Siam

2018-06-01

Jatropha seeds can be used to produce high-quality biodiesel due to their high oil content. However, Jatropha produces low numbers of female flowers, which limits seed yield. Paclobutrazol (PCB), a plant growth retardant, can increase number of Jatropha female flowers and seed yield. However, the underlying mechanisms of flower development after PCB treatment are not well understood. To identify the critical genes associated with flower development, the transcriptome of flower buds following PCB treatment was analyzed. Scanning Electron Microscope (SEM) analysis revealed that the flower developmental stage between PCB-treated and control flower buds was similar. Based on the presence of sex organs, flower buds at 0, 4, and 24 h after treatment were chosen for global transcriptome analysis. In total, 100,597 unigenes were obtained, 174 of which were deemed as interesting based on their response to PCB treatment. Our analysis showed that the JcCKX5 and JcTSO1 genes were up-regulated at 4 h, suggesting roles in promoting organogenic capacity and ovule primordia formation in Jatropha. The JcNPGR2, JcMGP2-3, and JcHUA1 genes were down-regulated indicating that they may contribute to increased number of female flowers and amount of seed yield. Expression of cell division and cellulose biosynthesis-related genes, including JcGASA3, JcCycB3;1, JcCycP2;1, JcKNAT7, and JcCSLG3 was decreased, which might have caused the compacted inflorescences. This study represents the first report combining SEM-based morphology, qRT-PCR and transcriptome analysis of PCB-treated Jatropha flower buds at different stages of flower development. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

An apple MYB transcription factor, MdMYB3, is involved in regulation of anthocyanin biosynthesis and flower development

PubMed Central

2013-01-01

suggesting that this TF is involved in regulation of flower development. Conclusions This study has identified a novel MYB transcription factor in the apple genome. This TF, designated as MdMYB3, is involved in transcriptional activation of several flavonoid pathway genes. Moreover, this TF not only regulates the accumulation of anthocyanin in the skin of apple fruits, but it is also involved in the regulation of flower development, particularly that of pistil development. PMID:24199943

Interacting effects of genetic variation for seed dormancy and flowering time on phenology, life history, and fitness of experimental Arabidopsis thaliana populations over multiple generations in the field.

PubMed

Taylor, Mark A; Cooper, Martha D; Sellamuthu, Reena; Braun, Peter; Migneault, Andrew; Browning, Alyssa; Perry, Emily; Schmitt, Johanna

2017-10-01

Major alleles for seed dormancy and flowering time are well studied, and can interact to influence seasonal timing and fitness within generations. However, little is known about how this interaction controls phenology, life history, and population fitness across multiple generations in natural seasonal environments. To examine how seed dormancy and flowering time shape annual plant life cycles over multiple generations, we established naturally dispersing populations of recombinant inbred lines of Arabidopsis thaliana segregating early and late alleles for seed dormancy and flowering time in a field experiment. We recorded seasonal phenology and fitness of each genotype over 2 yr and several generations. Strong seed dormancy suppressed mid-summer germination in both early- and late-flowering genetic backgrounds. Strong dormancy and late-flowering genotypes were both necessary to confer a winter annual life history; other genotypes were rapid-cycling. Strong dormancy increased within-season fecundity in an early-flowering background, but decreased it in a late-flowering background. However, there were no detectable differences among genotypes in population growth rates. Seasonal phenology, life history, and cohort fitness over multiple generations depend strongly upon interacting genetic variation for dormancy and flowering. However, similar population growth rates across generations suggest that different life cycle genotypes can coexist in natural populations. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Flower tracking in hawkmoths: behavior and energetics.

PubMed

Sprayberry, Jordanna D H; Daniel, Thomas L

2007-01-01

As hovering feeders, hawkmoths cope with flower motions by tracking those motions to maintain contact with the nectary. This study examined the tracking, feeding and energetic performance of Manduca sexta feeding from flowers moving at varied frequencies and in different directions. In general we found that tracking performance decreased as frequency increased; M. sexta tracked flowers moving at 1 Hz best. While feeding rates were highest for stationary flowers, they remained relatively constant for all tested frequencies of flower motion. Calculations of net energy gain showed that energy expenditure to track flowers is minimal compared to energy intake; therefore, patterns of net energy gain mimicked patterns of feeding rate. The direction effects of flower motion were greater than the frequency effects. While M. sexta appeared equally capable of tracking flowers moving in the horizontal and vertical motion axes, they demonstrated poor ability to track flowers moving in the looming axis. Additionally, both feeding rates and net energy gain were lower for looming axis flower motions.

cDNAs for the synthesis of cyclic carotenoids in petals of Gentiana lutea and their regulation during flower development.

PubMed

Zhu, Changfu; Yamamura, Saburo; Nishihara, Masashiro; Koiwa, Hiroyuki; Sandmann, Gerhard

2003-02-20

cDNAs encoding lycopene epsilon -cyclase, lycopene beta-cyclase, beta-carotene hydroxylase and zeaxanthin epoxidase were isolated from a Gentiana lutea petal cDNA library. The function of all cDNAs was analyzed by complementation in Escherichia coli. Transcript levels during different stages of flower development of G. lutea were determined and compared to the carotenoid composition. Expression of all genes increased by a factor of up to 2, with the exception of the lycopene epsilon -cyclase gene. The transcript amount of the latter was strongly decreased. These results indicate that during flower development, carotenoid formation is enhanced. Moreover, metabolites are shifted away from the biosynthetic branch to lutein and are channeled into beta-carotene and derivatives.

Clipping affects flowering of California poppy at two growth stages

Treesearch

Raymond D. Ratliff; Richard L. Hubbard

1975-01-01

The effects of clipping California-poppy (Eschscholzia californica Cham.) at various growth stages on plant survival, flowering, herbage yield, and root production were studied at the San Joaquin Experimental Range, in central California. Plants were clipped once to a 2-cm stubble at one of six stages. Through the early reproductive stage, a single...

Blooming Knit Flowers: Loop-Linked Soft Morphing Structures for Soft Robotics.

PubMed

Han, Min-Woo; Ahn, Sung-Hoon

2017-04-01

A loop-linked structure, which is capable of morphing in various modes, including volumetric transformation, is developed based on knitting methods. Morphing flowers (a lily-like, a daffodil-like, gamopetalous, and a calla-like flower) are fabricated using loop patterning, and their blooming motion is demonstrated by controlling a current that selectively actuates the flowers petals. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Phytoplasma Effector SAP54 Induces Indeterminate Leaf-Like Flower Development in Arabidopsis Plants1[C][W][OA

PubMed Central

MacLean, Allyson M.; Sugio, Akiko; Makarova, Olga V.; Findlay, Kim C.; Grieve, Victoria M.; Tóth, Réka; Nicolaisen, Mogens; Hogenhout, Saskia A.

2011-01-01

Phytoplasmas are insect-transmitted bacterial plant pathogens that cause considerable damage to a diverse range of agricultural crops globally. Symptoms induced in infected plants suggest that these phytopathogens may modulate developmental processes within the plant host. We report herein that Aster Yellows phytoplasma strain Witches’ Broom (AY-WB) readily infects the model plant Arabidopsis (Arabidopsis thaliana) ecotype Columbia, inducing symptoms that are characteristic of phytoplasma infection, such as the production of green leaf-like flowers (virescence and phyllody) and increased formation of stems and branches (witches’ broom). We found that the majority of genes encoding secreted AY-WB proteins (SAPs), which are candidate effector proteins, are expressed in Arabidopsis and the AY-WB insect vector Macrosteles quadrilineatus (Hemiptera; Cicadellidae). To identify which of these effector proteins induce symptoms of phyllody and virescence, we individually expressed the effector genes in Arabidopsis. From this screen, we have identified a novel AY-WB effector protein, SAP54, that alters floral development, resulting in the production of leaf-like flowers that are similar to those produced by plants infected with this phytoplasma. This study offers novel insight into the effector profile of an insect-transmitted plant pathogen and reports to our knowledge the first example of a microbial pathogen effector protein that targets flower development in a host. PMID:21849514

Endogenous ethylene does not regulate opening of unstressed Iris flowers but strongly inhibits it in water-stressed flowers.

PubMed

Çelikel, Fisun G; van Doorn, Wouter G

2012-09-15

The floral buds of Iris flowers (Iris x hollandica) are enclosed by two sheath leaves. Flower opening depends on lifting the flower up to a position whereby the tepals can move laterally. This upward movement is carried out by elongation of the subtending pedicel and ovary. In the pedicels and ovaries of unstressed control flowers, the concentration of ACC (1-aminocyclopropane-1-carboxylic acid) and the rate of ethylene production increased during d 0-1 of flower opening, and then decreased. Exposure to ≥200 nL L(-1) ethylene for 24 h at 20°C inhibited elongation of the pedicel+ovary, and inhibited flower opening. However, pulsing of unstressed flowers with solutions containing inhibitors of ethylene synthesis (AOA, AVG), or an inhibitor of ethylene action (STS), did not affect pedicel+ovary elongation or flower opening. When the flowers were dehydrated for 2 d at 20°C and 60% RH, they did not open when subsequently placed in water, and showed inhibited elongation in the pedicel+ovary. This dehydration treatment resulted in elevated pedicel+ovary ACC levels and in increased ethylene production. Treatment with STS prevented the increase in ACC levels and ethylene production, overcame the effect of dehydration on elongation of the pedicel+ovary, and resulted in full flower opening. It is concluded that flower opening in unstressed Iris flowers is not regulated by endogenous ethylene. An increase in endogenous ethylene above normal levels during stress, by contrast, strongly inhibited flower opening, due to its inhibitory effect on elongation of the pedicel+ovary. Copyright © 2012 Elsevier GmbH. All rights reserved.

Identification of Regulatory Genes Implicated in Continuous Flowering of Longan (Dimocarpus longan L.)

PubMed Central

Jia, Tianqi; Wei, Danfeng; Meng, Shan; Allan, Andrew C.; Zeng, Lihui

2014-01-01

Longan (Dimocarpus longan L.) is a tropical/subtropical fruit tree of significant economic importance in Southeast Asia. However, a lack of transcriptomic and genomic information hinders research on longan traits, such as the control of flowering. In this study, high-throughput RNA sequencing (RNA-Seq) was used to investigate differentially expressed genes between a unique longan cultivar ‘Sijimi’(S) which flowers throughout the year and a more typical cultivar ‘Lidongben’(L) which flowers only once in the season, with the aim of identifying candidate genes associated with continuous flowering. 36,527 and 40,982 unigenes were obtained by de novo assembly of the clean reads from cDNA libraries of L and S cultivars. Additionally 40,513 unigenes were assembled from combined reads of these libraries. A total of 32,475 unigenes were annotated by BLAST search to NCBI non-redundant protein (NR), Swiss-Prot, Clusters of Orthologous Groups (COGs) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. Of these, almost fifteen thousand unigenes were identified as significantly differentially expressed genes (DEGs) by using Reads Per kb per Million reads (RPKM) method. A total of 6,415 DEGs were mapped to 128 KEGG pathways, and 8,743 DEGs were assigned to 54 Gene Ontology categories. After blasting the DEGs to public sequence databases, 539 potential flowering-related DEGs were identified. In addition, 107 flowering-time genes were identified in longan, their expression levels between two longan samples were compared by RPKM method, of which the expression levels of 15 were confirmed by real-time quantitative PCR. Our results suggest longan homologues of SHORT VEGETATIVE PHASE (SVP), GIGANTEA (GI), F-BOX 1 (FKF1) and EARLY FLOWERING 4 (ELF4) may be involved this flowering trait and ELF4 may be a key gene. The identification of candidate genes related to continuous flowering will provide new insight into the molecular process of regulating flowering time in woody