Home About us Contact
|
Home About us Contact | ||
|
|
||
Petals
Terms modified by Petals Selected AbstractsThe whorl-specific action of a petunia class B floral homeotic geneGENES TO CELLS, Issue 2 2000Suguru Tsuchimoto Background GREEN PETAL (GP) is thought to be a petunia class B floral homeotic gene, because the gp mutant flower displays a severe homeotic conversion of petals into sepals in the second whorl. However, since the third whorl stamens remain unaffected in the gp null mutant, gp is different from class B mutants in Arabidopsis and Antirrhinum, which also show a conversion of the third whorl stamens into the carpelloid tissue. BLIND (BL) is thought to be a petunia class A floral homeotic gene, because the bl mutant flower displays homeotic conversions of sepals into the stigmatoid tissue in the first whorl and of the corolla limb into antheroid structures in the second whorl. Results A double mutant line homozygous for both bl and gp mutations was constructed. The bl gp double mutant flower displays homeotic conversions of sepals into the stigmatoid tissue in the first whorl and of the corolla limb into antheroid structures with stigmatoid tips in the second whorl. In the third and fourth whorls of the mutant flower, organs remained unchanged. In the gp flower, a petunia B-type gene FBP1 is expressed strongly in the third whorl organs, but much more weakly in the second whorl organs. In the bl gp flower, FBP1 was found to be expressed strongly in the second whorl organs as well as in the third whorl organs. Conclusions Petunia has a class B gene other than GP that determines organ identities, both in the second and third whorls of the double mutant flower, and the action of the postulated class B gene (here called PhBX) is prevented by the BL gene in the second whorl of the gp flower. PhBX appears to be a gene that specifically interacts with the FBP1 gene, and is involved in the up-regulation of FBP1. [source] Genetic Analysis of ele Mutants and Comparative Mapping of ele1 Locus in the Control of Organ Internal Asymmetry in Garden PeaJOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 6 2010Xin Li Previous study has shown that during zygomorphic development in garden pea (Pisum sativum L.), the organ internal (IN) asymmetry of lateral and ventral petals was regulated by a genetic locus, SYMMETRIC PETAL 1 (SYP1), while the dorsoventral (DV) asymmetry was determined by two CYC - like TCP genes or the PsCYC genes, KEELED WINGS (K) and LOBED STANDARD 1 (LST1). In this study, two novel loci, ELEPHANT EAR-LIKE LEAF 1 (ELE1) and ELE2 were characterized. These mutants exhibit a similar defect of IN asymmetry as syp1 in lateral and ventral petals, but also display pleiotropic effects of enlarged organ size. Genetic analysis showed that ELE1 and ELE2 were involved in same genetic pathway and the enlarged size of petals but not compound leaves in ele2 was suppressed by introducing k and lst1, indicating that the enlargement of dorsal petal in ele2 requires the activities of K and LST1. An experimental framework of comparative genomic mapping approach was set up to map and clone LjELE1 locus in Lotus japonicus. Cloning the ELE1 gene will shed light on the underlying molecular mechanism during zygomorphic development and further provide the molecular basis for genetic improvement on legume crops. [source] Proliferating Floral Organs (Pfo), a Lotus japonicus gene required for specifying floral meristem determinacy and organ identity, encodes an F-box proteinTHE PLANT JOURNAL, Issue 4 2003Shulu Zhang Summary To study flower development in the model legume Lotus japonicus, a population of transgenic plants containing a maize transposable element (Ac) in their genome was screened for floral mutants. One mutation named proliferating floral organs (pfo) causes plants to produce a large number of sepal-like organs instead of normal flowers. It segregates as a single recessive Mendelian locus, and causes sterility. Scanning electron microscopy revealed that pfo affects the identity, number and arrangement of floral organs. Sepal-like organs form in the first whorl, and secondary floral meristems are produced in the next whorl. These in turn produce sepal-like organs in the first whorl and floral meristems in the second whorl, and the process is reiterated. Petals and stamens are absent while carpels are either absent or reduced. The pfo phenotype was correlated with the presence of an Ac insertion yielding a 1.6-kb HindIII restriction fragment on Southern blots. Both the mutant phenotype and this Ac element are unstable. Using the transposon as a tag, the Pfo gene was isolated. Conceptual translation of Pfo predicts a protein containing an F-box, with high overall similarity to the Antirrhinum FIMBRIATA, Arabidopsis UNUSUAL FLORAL ORGANS and Pisum sativum Stamina pistilloida proteins. This suggests that Pfo may regulate floral organ identity and meristem determinacy by targeting proteins for ubiquitination. [source] Petals may act as a reward: myrmecochory in shrubby Darwinia species of south-eastern AustraliaAUSTRAL ECOLOGY, Issue 3 2009TONY D. AULD Abstract The removal rates of fruits (the diaspore) were assessed in exclusion experiments in three shrubby species of Darwinia, endemic to the Sydney Basin of south-eastern Australia. There was a clear pattern of fruit removal in just a few days by small species of ants from the genera Iridomyrmex, Crematogaster and Pheidole. When only ants had access to fruits an average of 41% of fruits were removed, whereas when only vertebrates had access an average of 13% of fruits were removed. There was some variation in the number of fruits removed both between species and within species across study sites or annual seed crops. When ants had access to seeds this variation in removal amounted to 10,80% over 1,4 days. Uniquely in Darwinia, it is the old petals (which remain attached to the fruit) that are attractive to the ants, rather than a specific lipid body. This likely represents a case of successful ecological fitting by Darwinia to take advantage of the widespread presence of myrmecochory in the Australian flora. [source] Genetic Analysis of ele Mutants and Comparative Mapping of ele1 Locus in the Control of Organ Internal Asymmetry in Garden PeaJOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 6 2010Xin Li Previous study has shown that during zygomorphic development in garden pea (Pisum sativum L.), the organ internal (IN) asymmetry of lateral and ventral petals was regulated by a genetic locus, SYMMETRIC PETAL 1 (SYP1), while the dorsoventral (DV) asymmetry was determined by two CYC - like TCP genes or the PsCYC genes, KEELED WINGS (K) and LOBED STANDARD 1 (LST1). In this study, two novel loci, ELEPHANT EAR-LIKE LEAF 1 (ELE1) and ELE2 were characterized. These mutants exhibit a similar defect of IN asymmetry as syp1 in lateral and ventral petals, but also display pleiotropic effects of enlarged organ size. Genetic analysis showed that ELE1 and ELE2 were involved in same genetic pathway and the enlarged size of petals but not compound leaves in ele2 was suppressed by introducing k and lst1, indicating that the enlargement of dorsal petal in ele2 requires the activities of K and LST1. An experimental framework of comparative genomic mapping approach was set up to map and clone LjELE1 locus in Lotus japonicus. Cloning the ELE1 gene will shed light on the underlying molecular mechanism during zygomorphic development and further provide the molecular basis for genetic improvement on legume crops. [source] Characterisation of aurone biosynthesis in Antirrhinum majusPHYSIOLOGIA PLANTARUM, Issue 4 2006Kevin M. Davies Aurones are bright yellow flavonoids produced in petals of a limited range of plant species, including Antirrhinum majus. The biosynthesis of aurones is thought to occur by the action of aureusidin synthase (AUS), and possibly aureusidin 7- O -glucosyltransferase (A7GT). The temporal and spatial occurrence of AUS and A7GT transcript was examined in wild-type A. majus and two mutant lines; sulfurea, which has increased aurone production in petals, and violacea, which has reduced aurone production. AUS and A7GT transcript abundance was similar in all three lines, increasing during flower development coincident with yellow coloration. The spatial pattern of AUS occurrence was also similar in all three lines, being spatially restricted to the inner epidermis of the face and throat of the lower petal. A new recessive line (CFR1011) with greatly reduced aurone production in all parts of the petal was identified by ethylmethanesulfonate mutagenesis of the homozygous recessive sulfurea line. Transcript abundance for AUS was not changed in the CFR1011 line compared with the wild-type line, and neither were any point mutations detected in the coding sequences for AUS or A7GT. Thus, the sulfurea, violacea and CFR1011 mutations do not seem to control aurone production through a change in transcript abundance of the predicted biosynthetic genes AUS or A7GT. To examine AUS gene regulation further, the putative AUS gene promoter region was isolated and compared with other A. majus flavonoid gene promoters. A number of conserved potential regulatory regions were identified, in particular a consensus site for the MYB-type transcription factors. [source] MADS-Box Genes Controlling Flower Development in RicePLANT BIOLOGY, Issue 1 2003F. Fornara Abstract: The separation between monocot and dicot plants occurred about 120 - 180 million years ago and since then major morphological changes have led to the striking differences that can be observed today. To understand whether, despite these differences, the processes controlling flower development are fundamentally comparable in dicot and monocot species, it is necessary to perform comparative studies. However, until recently flower development has been studied mainly in dicot plant species. Genetic and molecular analyses of two dicot model species, Arabidopsis thaliana and Antirrhinum majus, led to the formulation of the ABC model of flower development that describes how the combined activities of three classes of genes are required to drive flower organ development. This model has recently been extended by the inclusion of two other gene classes, namely D and E, which are involved in ovule development, and petal, stamen and carpel development, respectively. Most of the A, B, C, D and E genes identified so far have been shown to encode MADS-box transcription factors. In rice a number of regulatory genes belonging to the MADS-box transcription factor family have been cloned in the last few years and the functions of some of them have been investigated in detail. Here we review the current state of knowledge on rice flower development and focus on MADS-box genes that determine floral organ identity in this species. We compare results obtained in rice with the information known for Arabidopsis and the differences between these two species are discussed. [source] Genetic variation in Candidatus Phytoplasma australiensePLANT PATHOLOGY, Issue 1 2005C. Streten This study examined whether genes that are less conserved than the 16S rRNA gene can distinguish Candidatus Phytoplasma australiense strains that are identical based on their 16S rRNA genes, with a view to providing insight into their origins and distribution, and any patterns of association with particular plant hosts. Sequence analysis of the tuf gene and rp operon showed that Ca. P. australiense strains could be differentiated into four subgroups, named 16SrXII-B (tuf -Australia I; rp -A), 16SrXII-B (tuf -New Zealand I; rp -B), 16SrXII-B (tuf -New Zealand II) and 16SrXII-B (rp -C). Strawberry lethal yellows 1, strawberry green petal, Australian grapevine yellows, pumpkin yellow leaf curl and cottonbush witches' broom phytoplasmas were designated members of the 16SrXII-B (tuf -Australia I; rp -A) subgroup. The strawberry lethal yellows 2 and cottonbush reduced yellow leaves phytoplasmas were assigned to the 16SrXII (tuf -New Zealand II; rp -B) subgroup. No relationship was observed between these phytoplasma subgroups and collection date, location or host plant. However, the study revealed evolutionary divergence in the 16SrXII group. [source] The petunia AGL6 gene has a SEPALLATA -like function in floral patterningTHE PLANT JOURNAL, Issue 1 2009Anneke S. Rijpkema Summary SEPALLATA (SEP) MADS-box genes are required for the regulation of floral meristem determinacy and the specification of sepals, petals, stamens, carpels and ovules, specifically in angiosperms. The SEP subfamily is closely related to the AGAMOUS LIKE6 (AGL6) and SQUAMOSA (SQUA) subfamilies. So far, of these three groups only AGL6 -like genes have been found in extant gymnosperms. AGL6 genes are more similar to SEP than to SQUA genes, both in sequence and in expression pattern. Despite the ancestry and wide distribution of AGL6 -like MADS-box genes, not a single loss-of-function mutant exhibiting a clear phenotype has yet been reported; consequently the function of AGL6 -like genes has remained elusive. Here, we characterize the Petunia hybrida AGL6 (PhAGL6, formerly called PETUNIA MADS BOX GENE4/pMADS4) gene, and show that it functions redundantly with the SEP genes FLORAL BINDING PROTEIN2 (FBP2) and FBP5 in petal and anther development. Moreover, expression analysis suggests a function for PhAGL6 in ovary and ovule development. The PhAGL6 and FBP2 proteins interact in in vitro experiments overall with the same partners, indicating that the two proteins are biochemically quite similar. It will be interesting to determine the functions of AGL6 -like genes of other species, especially those of gymnosperms. [source] Analysis of B function in legumes: PISTILLATA proteins do not require the PI motif for floral organ development in Medicago truncatulaTHE PLANT JOURNAL, Issue 1 2009Reyes Benlloch Summary The B-class gene PISTILLATA (PI) codes for a MADS-box transcription factor required for floral organ identity in angiosperms. Unlike Arabidopsis, it has been suggested that legume PI genes contribute to a variety of processes, such as the development of floral organs, floral common petal,stamen primordia, complex leaves and N-fixing root nodules. Another interesting feature of legume PI homologues is that some of them lack the highly conserved C-terminal PI motif suggested to be crucial for function. Therefore, legume PI genes are useful for addressing controversial questions on the evolution of B-class gene function, including how they may have diverged in both function and structure to affect different developmental processes. However, functional analysis of legume PI genes has been hampered because no mutation in any B-class gene has been identified in legumes. Here we fill this gap by studying the PI function in the model legume species Medicago truncatula using mutant and RNAi approaches. Like other legume species, M. truncatula has two PI homologues. The expression of the two genes, MtPI and MtNGL9, has strongly diverged, suggesting differences in function. Our analyses show that these genes are required for petal and stamen identity, where MtPI appears to play a predominant role. However, they appear not to be required for development of the nodule, the common primordia or the complex leaf. Moreover, both M. truncatula PI homologues lack the PI motif, which indicates that the C-terminal motif is not essential for PI activity. [source] Tobacco bZIP transcription factor TGA2.2 and related factor TGA2.1 have distinct roles in plant defense responses and plant developmentTHE PLANT JOURNAL, Issue 1 2005Corinna Thurow Summary Salicylic acid (SA) is a crucial internal signaling molecule needed for the induction of plant defense responses upon attack of a variety of pathogens. Basic leucine zipper transcription factors of the TGA family bind to activating sequence-1 (as-1) -like elements which are SA-responsive cis elements found in promoters of ,immediate early' and ,late' SA-inducible genes. TGA2.2 constitutes the main component of tobacco as -1 -binding factor-1 (ASF-1). TGA2.1, which differs from TGA2.2 by being able to activate transcription in yeast, constitutes a minor fraction of the complex. Both proteins interact with NPR1, a protein essential for SA inducibility of ,late' genes. Here we demonstrate using dsRNAi mediated gene silencing that reducing the amount of TGA2.2 and TGA2.1 correlates with a significant decrease in ASF-1 activity and with a decreased inducibility of both ,immediate early' and ,late' genes. In contrast, reducing the amount of TGA2.1 alone had no effect on the expression of these target genes suggesting that TGA2.1 is dispensable for SA-inducible gene expression from the as-1 element. Expression of a TGA2.2 mutant unable to form heterodimers with the endogenous pool of TGA factors led to reduced SA-inducibility of ,immediate early' gene Nt103, indicating that the native leucine zipper is important for the protein to act positively on transcription. Plants with reduced amounts of TGA2.1 developed petal like stamens indicating a regulatory role of TGA2.1 in defining organ identity in tobacco flowers. A model is suggested that unifies conflicting results on the function of tobacco TGA factors with respect to activation of the ,late'PR-1a promoter. [source] China rose (Hibiscus rosasinensis) petals: a potent natural carotenoid source for goldfish (Carassius auratus L.)AQUACULTURE RESEARCH, Issue 11 2007Archana Sinha Abstract Goldfish (Carassius auratus) are in demand in world markets due to their attractive golden colour. Carotenoids are the primary source of colour in the skin of fish. To optimize the colour in captivity, fish must obtain an adequate level of carotenoids in their feed. With this objective, four natural colour enhancers were tested. A common batch of feed was divided into five equal portions and colour ingredients, spirulina (D-S), china rose petals (D-C), marigold petals (D-M) and Lactobacil, a commercial probiotic (D-L), were added at 5 mg kg,1 to four portions of feed; one portion (D-O) was kept as a control without any additive. A feeding trial was conducted for 8 weeks. Each 70 L aquarium was stocked with 10 fish (average weight 1.6 g) and feed was given at 5% of the body weight. Growth rate, survival, biochemical composition and pigmentation in the skin of fish were measured. Histological studies of gonads were also conducted. Growth of fish in different treatments was significantly different. There was no difference in the proximate composition of the fish at the start of the experiment but after 8 weeks of feeding, fish fed the diet supplemented with china rose petals had a lower moisture content (70.48%) and higher protein (17.7%) and lipid (5.25%) levels than the group fed the control diet. Pigmentation was the highest (4.01 ,g g,1) in D-C, followed by D-M (3.16 ,g g,1), D-S (2.92 ,g g,1) and D-L (2.84 ,g g,1) and the lowest (0.24 ,g g,1) in D-O. Gonad development of fish fed with the D-C diet was better compared with the gonads of control (D-O) fish, followed by D-M-, D-L- and D-S-fed fish. Gonads of fish, fed D-C, showed well-marked changes in the testis where a large number of seminiferous tubules bound together by means of a thin layer of connective tissue were observed. These tubules were highly convoluted and were separated from each other by thin connective tissue stroma. The intra space contained connective tissue, blood capillaries and interstitial cells. The spermatogonia could be seen as a large spherical cell containing a large central nucleus with a distinct nucleolus. The study shows that the china rose (Hibiscus rosasinensis) petal is a potent natural carotenoid source for goldfish to enhance its colour and also accelerate gonadal development. [source] Roles of synorganisation, zygomorphy and heterotopy in floral evolution: the gynostemium and labellum of orchids and other lilioid monocotsBIOLOGICAL REVIEWS, Issue 3 2002PAULA J. RUDALL ABSTRACT A gynostemium, comprising stamen filaments adnate to a syncarpous style, occurs in only three groups of monocots: the large family Orchidaceae (Asparagales) and two small genera Pauridia (Hypoxidaceae: Asparagales) and Corsia (Corsiaceae, probably in Liliales), all epigynous taxa. Pauridia has actinomorphic (polysymmetric) flowers, whereas those of Corsia and most orchids are strongly zygomorphic (monosymmetric) with a well-differentiated labellum. In Corsia the labellum is formed from the outer median tepal (sepal), whereas in orchids it is formed from the inner median tepal (petal) and is developmentally adaxial (but positionally abaxial in orchids with resupinate flowers). Furthermore, in orchids zygomorphy is also expressed in the stamen whorls, in contrast to Corsia. In Pauridia a complete stamen whorl is suppressed, but the ,lost' outer whorl is fused to the style. The evolution of adnation and zygomorphy are discussed in the context of the existing phylogenetic framework in monocotyledons. An arguably typological classification of floral terata is presented, focusing on three contrasting modes each of peloria and pseudopeloria. Dynamic evolutionary transitions in floral morphology are assigned to recently revised concepts of heterotopy (including homeosis) and heterochrony, seeking patterns that delimit developmental constraints and allow inferences regarding underlying genetic controls. Current evidence suggests that lateral heterotopy is more frequent than acropetal heterotopy, and that full basipetal heterotopy does not occur. Pseudopeloria is more likely to generate a radically altered yet functional perianth, but is also more likely to cause acropetal modification of the gynostemium. These comparisons indicate that there are at least two key genes or sets of genes controlling adnation, adaxial stamen suppression and labellum development in lilioid monocots; at least one is responsible for stamen adnation to the style (i.e. gynostemium formation), and another controls adaxial stamen suppression and adaxial labellum formation in orchids. Stamen adnation to the style may be a product of over-expression of the genes related to epigyny (i.e. a form of hyper-epigyny). If, as seems likely, stamen-style adnation preceded zygomorphy in orchid evolution, then the flowers of Pauridia may closely resemble those of the immediate ancestors of Orchidaceae, although existing molecular phylogenetic data indicate that a sister-group relationship is unlikely. The initial radiation in Orchidaceae can be attributed to the combination of hyper-epigyny, zygomorphy and resupination, but later radiations at lower taxonomic levels that generated the remarkable species richness of subfamilies Orchidoideae and Epidendroideae are more likely to reflect more subtle innovations that directly influence pollinator specificity, such as the development of stalked pollinaria and heavily marked and or spur-bearing labella. [source] Floral anatomy and systematics of Bretschneidera (Bretschneideraceae)BOTANICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 1 2002LOUIS P. RONSE DE CRAENE FLS External morphology and anatomy of the flower and pollen of Bretschneidera sinensis Hemsl. are described to clarify the position of the family Bretschneideraceae relative to the Sapindales and the glucosinolate-producing families. Anatomical and micromorphological characters are investigated and sections are used to understand the structure of the flower. Observation of buds and sections reveal that the flower is obliquely monosymmetric, with the symmetry line running from one petal to a sepal. The upper petal shields the stamens and pistil and becomes positioned apically by the partial resupination of the pedicel. The octomerous androecium is characterized by variable empty positions which are related to the variable insertion of the three carpels. The loss of stamens is linked with a displacement of the remaining stamens. Floral anatomy demonstrates the presence of a nectary extending on the hypanthium from the base of the filaments to the base of the gynoecium. Details of floral anatomy are compared with members of Sapindaceae, Hippocastanaceae, Moringaceae, Akaniaceae, Tropaeolaceae and Capparaceae. Comparison with other characters supports a close relationship with Akaniaceae and Tropaeolaceae in an order Tropaeolales, in concordance with macromolecular results, either at the base of the glucosinolate clade, or in remote connection with the Sapindales. A number of floral anatomical characters with a strong phylogenetic signal are highlighted. © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society, 2002, 139, 29,45. [source] Thrips see red , flower colour and the host relationships of a polyphagous anthophilic thripsECOLOGICAL ENTOMOLOGY, Issue 5 2007A. YAKU Abstract 1.,The common blossom thrips, Frankliniella schultzei, is a polyphagous anthophilic species that colonises a wide range of host-plant species across different plant taxa. The environmental cues used by these polyphagous insects to recognise and locate host plants are not known. We therefore determined if colour is an important environmental signal used by F. schultzei to recognise flowers of eight of its more significant host-plant species. 2.,The effect of flower colour on the colonisation of different host plant species by F. schultzei was investigated by collecting and analysing the following: (a) numbers of thrips from different heights and aspects of the primary host plant Malvaviscus arboreus, (b) thrips distribution within flowers of Hibiscus rosasinensis, (c) colour reflectance from flowers of eight different host-plant species, and (d) reflectance from different coloured sticky traps and the number of thrips trapped on them at different times of the day and on different dates. 3.,The results indicate that: (a) the thrips (both sexes) concentrate towards the top of the primary host plant M. arboreus and are not distributed differentially according to sunny or shady aspect of the plant, (b) the number of female thrips on H. rosasinensis was higher in anthers compared to petals (corolla) and the basal parts of the flower, and males were as numerous on the petals as were females, and (c) there is a common floral reflectance pattern (but with different intensities) across the eight host plant species, mainly in the red part of the spectrum (600,700 nm). 4.,Results of colour sticky trapping show that red attracts more female thrips compared to any other colour and that most were caught between 09.00 and 11.00 hours. By contrast, more male thrips were trapped between 07.00 and 09.00 hours. Males were more evenly distributed across the different colours but the highest numbers were associated with the yellow traps. 5.,The higher densities of thrips at the top of their host plant may be related to the early morning (07.00,11.00 hours) activity of the thrips, when the top portions of the plant are more exposed to sunlight. The sex-related distributions of F. schultzei thrips across time, coloured sticky traps, and various parts of the flowers seem to be related to mating swarm formation by the males, on the one hand, and the relative frequency and intensity of the use of M. arboreus by the females, on the other, as a feeding and oviposition site. Frankliniella schultzei females respond more strongly to red than to any other colours, so it is predicted that the spectral properties of colour recognition by this species will correlate with the predominant red reflectance of its primary host, M. arboreus, and that there may well be a sex-related difference in colour recognition within this species. [source] Study of the mechanism of microwave-assisted extraction of Mahonia bealei (Fort.) leaves and Chrysanthemum morifolium (Ramat.) petalsFLAVOUR AND FRAGRANCE JOURNAL, Issue 3 2004Shan Gao Abstract A study of microwave-assisted extraction (MAE) for berberine in Mahonia bealei (Fort.) was carried out with batch equipment, in order to investigate the mechanism of the extraction related to structural changes in the glands. The extracts were analysed by ultraviolet-visible spectrophotometry at 347 nm. The parameters investigated were solvent types, the intensity of microwave energy and the process ratio (g/ml) of materials to solvent volume. The microwave-assisted extraction of different moisture content of materials was developed and optimized by means of three-factor and three-level orthogonal designs. Electron and optical micrographs of M. bealei (Fort.) leaves and Chrysanthemum morifolium (Ramat.) petals showed that the mechanism of the extractions was related to structural changes in the plant cells. Copyright © 2004 John Wiley & Sons, Ltd. [source] The whorl-specific action of a petunia class B floral homeotic geneGENES TO CELLS, Issue 2 2000Suguru Tsuchimoto Background GREEN PETAL (GP) is thought to be a petunia class B floral homeotic gene, because the gp mutant flower displays a severe homeotic conversion of petals into sepals in the second whorl. However, since the third whorl stamens remain unaffected in the gp null mutant, gp is different from class B mutants in Arabidopsis and Antirrhinum, which also show a conversion of the third whorl stamens into the carpelloid tissue. BLIND (BL) is thought to be a petunia class A floral homeotic gene, because the bl mutant flower displays homeotic conversions of sepals into the stigmatoid tissue in the first whorl and of the corolla limb into antheroid structures in the second whorl. Results A double mutant line homozygous for both bl and gp mutations was constructed. The bl gp double mutant flower displays homeotic conversions of sepals into the stigmatoid tissue in the first whorl and of the corolla limb into antheroid structures with stigmatoid tips in the second whorl. In the third and fourth whorls of the mutant flower, organs remained unchanged. In the gp flower, a petunia B-type gene FBP1 is expressed strongly in the third whorl organs, but much more weakly in the second whorl organs. In the bl gp flower, FBP1 was found to be expressed strongly in the second whorl organs as well as in the third whorl organs. Conclusions Petunia has a class B gene other than GP that determines organ identities, both in the second and third whorls of the double mutant flower, and the action of the postulated class B gene (here called PhBX) is prevented by the BL gene in the second whorl of the gp flower. PhBX appears to be a gene that specifically interacts with the FBP1 gene, and is involved in the up-regulation of FBP1. [source] The comparison of in vivo antigenotoxic and antioxidative capacity of two propylene glycol extracts of Calendula officinalis (marigold) and vitamin E in young growing pigsJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 6 2009T. Franki Summary The objective of the study was to evaluate the protective effect of Calendula officinalis propylene glycol extracts against oxidative DNA damage and lipid peroxidation induced by high polyunsaturated fatty acid (PUFA) intake in young growing pigs. Forty young growing pigs were assigned to five treatment groups: control; oil (linseed oil supplementation); C. officinalis 1 and 2 groups (linseed oil plus 3 ml/day of C. officinalis propylene glycol extracts); and vitamin E group (linseed oil plus 100 mg/kg of vitamin E). Lymphocyte DNA fragmentation and 24-h urinary 8-hydroxy-2,-deoxyguanosine (8-OHdG) excretion were measured to determine DNA damage. Lipid peroxidation was studied by analysing plasma and urine malondialdehyde (MDA), and urine isoprostane concentrations (iPF2,-VI), total antioxidant status of plasma and glutathione peroxidase (GPx) assays. C. officinalis 1 (extract from petals) effectively protected DNA from oxidative damage. It indicated a numerical trend towards the reduction of plasma MDA and urinary iPF2,-VI excretion. Its effect was comparable with that of vitamin E. C. officinalis 2 (extract from flower tops) showed less antioxidant potential than the extract from petals. We can conclude that the amount of C. officinalis extracts proposed for internal use by traditional medicine protects the organism against DNA damage induced by high PUFA intake. [source] Morph-specific selection on floral traits in a polymorphic plantJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 6 2010D. VANHOENACKER Abstract Correlations between phenotypic traits are common in many organisms, but the relative importance of nonadaptive mechanisms and selection for the evolution and maintenance of such correlations are poorly understood. In polymorphic species, morphs may evolve quantitative differences in additional characters as a result of morph-specific selection. The perennial rosette herb Primula farinosa is polymorphic for scape length. The short-scaped morph is less damaged by grazers and seed predators but is more strongly pollen limited than the long-scaped morph. We examined whether morph-specific differences in biotic interactions are associated with differences in selection on two other traits affecting floral display (number of flowers and petal size) and on one trait likely to affect pollination efficiency (corolla tube width) in three P. farinosa populations. Differences in selection between morphs were detected in one population. In this population, selection for more flowers and larger petals was stronger in the short-scaped than in the long-scaped morph, and although there was selection for narrower corolla tubes in the short-scaped morph, no statistically significant selection on corolla tube width could be detected in the long-scaped morph. In the study populations, the short-scaped morph produced more and larger flowers and wider corolla tubes. Current morph-specific selection was thus only partly consistent with trait differences between morphs. The results provide evidence of morph-specific selection on traits associated with floral display and pollination efficiency, respectively. [source] Genetic Analysis of ele Mutants and Comparative Mapping of ele1 Locus in the Control of Organ Internal Asymmetry in Garden PeaJOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 6 2010Xin Li Previous study has shown that during zygomorphic development in garden pea (Pisum sativum L.), the organ internal (IN) asymmetry of lateral and ventral petals was regulated by a genetic locus, SYMMETRIC PETAL 1 (SYP1), while the dorsoventral (DV) asymmetry was determined by two CYC - like TCP genes or the PsCYC genes, KEELED WINGS (K) and LOBED STANDARD 1 (LST1). In this study, two novel loci, ELEPHANT EAR-LIKE LEAF 1 (ELE1) and ELE2 were characterized. These mutants exhibit a similar defect of IN asymmetry as syp1 in lateral and ventral petals, but also display pleiotropic effects of enlarged organ size. Genetic analysis showed that ELE1 and ELE2 were involved in same genetic pathway and the enlarged size of petals but not compound leaves in ele2 was suppressed by introducing k and lst1, indicating that the enlargement of dorsal petal in ele2 requires the activities of K and LST1. An experimental framework of comparative genomic mapping approach was set up to map and clone LjELE1 locus in Lotus japonicus. Cloning the ELE1 gene will shed light on the underlying molecular mechanism during zygomorphic development and further provide the molecular basis for genetic improvement on legume crops. [source] Floral Ontogeny of Two Species in Magnolia L.JOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 10 2006Feng-Xia Xu Abstract Floral ontogeny is described in two species of genus Magnolia (Magnoliaceae), Magnolia albosericea Chun et C. Tsoong, and M. amoena Cheng, representing subgenus Magnolia and subgenus Yulania in Magnolia, by using scanning electron microscope (SEM). The sequence of initiation of floral organs is from proximal to distal. The three distinct outermost and middle organs are initiated in sequence, but ultimately form a single whorl, thus their ontogeny is consistent with a sepal interpretation. The last three tepals (petals) alternate with the preceding tepal whorl. The members of androecium and gynoecium arise spirally, although the androecium shows some intermediacy between a spiral and whorled arrangement. The carpel primordia initiate in group of four to five. The order of stamen initiation within each tier is not determined. The floral ontogeny is remarkably homogeneous between the subgenus Magnolia and subgenus Yulania that does not support the resuming of genus Yulania. (Managing editor: Wei Wang) [source] Atomic Force Microscopy Characterization and Interpretation of Thin-Film Poly(butylene adipate) Spherulites with Ring BandsMACROMOLECULAR RAPID COMMUNICATIONS, Issue 15 2008Andreas Frömsdorf Abstract Atomic force microscopy characterization has been conducted to reveal the morphological difference between single-ring bands in poly(butylene adipate) (PBA). Furthermore, morphological features of the ring-less Maltese-cross spherulites are compared to the ring-band spherulites. Periodic changes in height seem to be common for either the ring-band or ring-less (Maltese-cross) crystal domains; however, the steepness in height change is greater for the ring-band crystal, while height change in the ring-less crystal exhibits a terrace-like layer pattern. In the ring-band crystal region, the lamellar stalks, which taper off to pointed needle-like stalks, monotonously protrude out of the layers of softer materials, with no signs of twisting, bending, or turning. In contrast, all lamellae in the ring-less (Maltese-cross) crystal region are uniform platelets arranged like flower petals in a layered pattern. [source] Genetic differentiation and reproductive isolation of a naturally occurring floral homeotic mutant within a wild-type population of Capsella bursa-pastoris (Brassicaceae)MOLECULAR ECOLOGY, Issue 12 2009STEFFEN HAMEISTER Abstract Apart from the common floral architecture in Brassicaceae, variation in flower morphology occurs in several genera within the family and is considered to affect speciation processes. We analysed genetic differentiation and flowering time variation of two floral variants of Capsella bursa-pastoris, the Spe variant and the wild-type, which occur sympatrically in a vineyard in southwest Germany. The Spe variant is characterized by an additional whorl of stamens instead of petals and was formerly classified as an independent taxon ,Capsella apetala' Opiz. Amplified fragment length polymorphism and allozyme analysis revealed a substantial genetic differentiation of the two floral variants and a higher genetic variation within the wild-type subpopulation compared with the Spe subpopulation. The low genetic variation in the mutant provided evidence of a recent local origin or recent introduction. Flowering time analysis indicated that, within the analysed population, the Spe variant flowers significantly later than the wild-type (P < 0.001). We conclude that the evolution and persistence of Spe within a wild-type population is facilitated by high selfing rates and been enhanced by a shift in flowering phenology. Hence, our data provide substantial evidence that the Spe phenotype has established itself as an isolated entity within a wild-type population and may thus serve as a model for the analysis of the evolutionary significance of homeotic mutants in wild populations. [source] Conservation and diversification of the symmetry developmental program among close relatives of snapdragon with divergent floral morphologiesNEW PHYTOLOGIST, Issue 3 2009Jill C. Preston Summary ,,Multiple evolutionary shifts in floral symmetry and stamen number have occurred in the snapdragon (Antirrhinum majus) family Veronicaceae. In Mohavea, Veronica and Gratiola there have been independent evolutionary reductions in stamen number and modifications to corolla shape. It is hypothesized that changes in the regulation of homologs of snapdragon dorsal flower identity genes CYCLOIDEA (CYC) and RADIALIS (RAD) underlie these floral transitions. ,,CYC -like and RAD -like genes from Veronica montana and Gratiola officinalis were cloned and sequenced, compared with homologs from other Veronicaceae species using phylogenetic analysis, and their expression was investigated by reverse transcriptase-polymerase chain reaction (RT-PCR) and in situ hybridization. ,,VmCYC1, GoCYC1, GoCYC2 and RAD -like genes are expressed exclusively in the dorsal region of floral meristems and developing flowers. Their expression patterns do not correlate with patterns of stamen arrest. VmCYC2 and GoCYC3 are expressed in both vegetative and floral tissues, with VmCYC2 being most abundant in all regions of the floral meristem and all petals. ,,These results support conservation of the floral symmetry gene network for Veronicaceae RAD -like and some CYC -like paralogs, suggest regulatory evolution of other CYC -like genes following gene duplication and implicate different genetic mechanisms underlying dorsal versus ventral stamen abortion within Veronica and Gratiola. [source] Programmed cell death (PCD) processes begin extremely early in Alstroemeria petal senescenceNEW PHYTOLOGIST, Issue 1 2003Carol Wagstaff Summary ,,In the Liliaceous species Alstroemeria, petal senescence is characterized by wilting and inrolling, terminating in abscission 8,10 d after flower opening. ,,In many species, flower development and senescence involves programmed cell death (PCD). PCD in Alstroemeria petals was investigated by light (LM) and transmission electron microscopy (TEM) (to study nuclear degradation and cellular integrity), DNA laddering and the expression programme of the DAD-1 gene. ,,TEM showed nuclear and cellular degradation commenced before the flowers were fully open and that epidermal cells remained intact whilst the mesophyll cells degenerated completely. DNA laddering increased throughout petal development. Expression of the ALSDAD-1 partial cDNA was shown to be downregulated after flower opening. ,,We conclude that some PCD processes are started extremely early and proceed throughout flower opening and senescence, whereas others occur more rapidly between stages 4,6 (i.e. postanthesis). The spatial distribution of PCD across the petals is discussed. Several molecular and physiological markers of PCD are present during Alstroemeria petal senescence. [source] Ranunculusanatolicus sp. nov. (Ranunculaceae) from northeast TurkeyNORDIC JOURNAL OF BOTANY, Issue 5-6 2007Ünal Akkemik RanunculusanatolicusÜ. Akkemik, E. Akalin & N. Özhatay sp. nov. from northeast Turkey is described and illustrated. The new species is related to R. fenzlii Boiss., R. caucasicus Bieb. subsp. subleiocarpus (Som. & Lev.) P. H. Davis, and R. dissectus Bieb. subsp. huetii (Boiss.) Davis, from which it mainly differs by its broadly cuneate leaflobes and multiplex petals (8,12). [source] A new genus of Sapindaceae from SomaliaNORDIC JOURNAL OF BOTANY, Issue 5 2004Mats Thulin The new genus Hirania (Sapindaceae), with the single species H. rosea from south-central Somalia, is decribed and illustrated. It is a shrub with simple, entire leaves, alternate or crowded on short-shoots, and without stipules. The inflorescences are branched with monochasially arranged, unisexual flowers. The flowers (only male ones known) are zygomorphic with five sepals with gland-tipped hairs along margins, four pink, subequal, clawed petals without appendages, and eight, glabrous stamens. The dark purple disk is narrow and tubular and consists of an upper broader segment partly enclosing a lower narrower segment. The closest relative is believed to be the Australian genus Diplopeltis. [source] Azimuthal anisotropy of light extraction from photonic crystal light-emitting diodesPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 6 2008Chun-Feng Lai Abstract Photonic crystal (PhC) light-emitting diodes (LEDs) exhibiting anisotropic light extraction have been investigated experimentally and theoretically. It is found that the anisotropic light extraction strongly depends on the lattice constant and orientation. Optical images of the anisotropy in the azimuthal direction are obtained using annular structure with triangular lattice. 6-fold symmetric light extraction patterns with varying number of petals are observed. More petals in multiple of 6 appear in the observed image with lattice constant increasing. This anisotropic behavior suggests a new means to optimize the PhC design of GaN LED for light extraction. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Characterisation of aurone biosynthesis in Antirrhinum majusPHYSIOLOGIA PLANTARUM, Issue 4 2006Kevin M. Davies Aurones are bright yellow flavonoids produced in petals of a limited range of plant species, including Antirrhinum majus. The biosynthesis of aurones is thought to occur by the action of aureusidin synthase (AUS), and possibly aureusidin 7- O -glucosyltransferase (A7GT). The temporal and spatial occurrence of AUS and A7GT transcript was examined in wild-type A. majus and two mutant lines; sulfurea, which has increased aurone production in petals, and violacea, which has reduced aurone production. AUS and A7GT transcript abundance was similar in all three lines, increasing during flower development coincident with yellow coloration. The spatial pattern of AUS occurrence was also similar in all three lines, being spatially restricted to the inner epidermis of the face and throat of the lower petal. A new recessive line (CFR1011) with greatly reduced aurone production in all parts of the petal was identified by ethylmethanesulfonate mutagenesis of the homozygous recessive sulfurea line. Transcript abundance for AUS was not changed in the CFR1011 line compared with the wild-type line, and neither were any point mutations detected in the coding sequences for AUS or A7GT. Thus, the sulfurea, violacea and CFR1011 mutations do not seem to control aurone production through a change in transcript abundance of the predicted biosynthetic genes AUS or A7GT. To examine AUS gene regulation further, the putative AUS gene promoter region was isolated and compared with other A. majus flavonoid gene promoters. A number of conserved potential regulatory regions were identified, in particular a consensus site for the MYB-type transcription factors. [source] The expression and promoter specificity of the birch homologs for PISTILLATA/GLOBOSA and APETALA3/DEFICIENSPHYSIOLOGIA PLANTARUM, Issue 2 2005Mika Lännenpää B-function genes determine the identity of petals and stamens in the flowers of model plants such as Arabidopsis and Antirrhinum. Here, we show that a putative B-function gene BpMADS2, a birch homolog for PISTILLATA, is expressed in stamens and carpels of birch inflorescences. We also present a novel birch gene BpMADS8, a homolog for APETALA3/DEFICIENS, which is expressed in stamens. Promoter-GUS analysis revealed that BpMADS2 promoter is active in the receptacle of Arabidopsis flower buds while BpMADS8 promoter is highly specific in mature stamens. BpMADS2 promoter::BARNASE construct prevented floral organ development in Arabidopsis and tobacco. In birch, inflorescences with degenerated stamens and carpels were obtained. BpMADS8::BARNASE resulted in degeneration of stamens in Arabidopsis and birch causing male sterility. In tobacco, only sepals were developed instead of normal flowers. The results show that the BpMADS2::BARNASE construct can be used to specifically disrupt floral organ development in phylogenetically distant plant species. The stamen-specific promoter of BpMADS8 is a promising tool for biotechnological applications in inducing male sterility or targeting gene expression in the late stamen development. [source] | ||||||||||||||||||||||||||||||||||