The role of genes influencing the corolla in pollination of <i>Antirrhinum majus</i>

Comba, Livio; Corbet, Sarah A.; Hunt, Harriet V.; Outram, S.; Parker, John; Glover, Beverley J.

doi:10.1046/j.1365-3040.2000.00580.x

Cited by 85 publications

(69 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…one of chromel, the other of alumel) was soldered onto the thicker wire (Wires, all from RS Components Ltd Corby, UK) using a standard aluminium solder. The wires were then insulated using a spray-on electrical circuit lacquer (Comba et al 2000). Illumination was provided by six Sylvania Activa 172 Professional 36W fluorescent tubes (Germany) that were modified with Phillips high frequency ballasts to have a flicker frequency greater than 1,200 Hz on a 12-h light/dark regime.…”

Section: Methodsmentioning

confidence: 99%

The interaction of temperature and sucrose concentration on foraging preferences in bumblebees

Whitney

Dyer

Chittka

et al. 2008

Naturwissenschaften

View full text Add to dashboard Cite

Several authors have found that flowers that are warmer than their surrounding environment have an advantage in attracting pollinators. Bumblebees will forage preferentially on warmer flowers, even if equal nutritional reward is available in cooler flowers. This raises the question of whether warmth and sucrose concentration are processed independently by bees, or whether sweetness detectors respond to higher sugar concentration as well as higher temperature. We find that bumblebees can use lower temperature as a cue to higher sucrose reward, showing that bees appear to process the two parameters strictly independently. Moreover, we demonstrate that sucrose concentration takes precedence over warmth, so that when there is a difference in sucrose concentration, bees will typically choose the sweeter feeder, even if the less sweet feeder is several degrees warmer.

show abstract

Section: Methodsmentioning

confidence: 99%

The interaction of temperature and sucrose concentration on foraging preferences in bumblebees

Whitney

Dyer

Chittka

et al. 2008

Naturwissenschaften

View full text Add to dashboard Cite

show abstract

“…The shape of the petal epidermal cells also affects the perceived intensity of the colour signal from the petals and its brightness as a result of differences in the reflection and absorption of light by these differently shaped cells (Gorton and Vogelmann, 1996;Kay, 1988;Kay et al, 1981;Noda et al, 1994). Field trials have shown that flowers of A. majus with conical cells (Mixta + ) are more attractive to bees than flowers with flat epidermal cells (mixta -), particularly under conditions of low pollinator density (Comba et al, 2000;. This might be due partly to the differences in the perceived colour intensity of the flowers, but pollinators showed preferences for flowers with conical epidermal cells even where no anthocyanin pigments were produced and the flowers were white.…”

Section: The Inner Epidermal Cell Layer Affects Overall Floral Architmentioning

confidence: 99%

“…Conical cells enhance the colour intensity and brightness of petal surfaces by reflecting a higher proportion of incident light into the epidermal cells, where more is absorbed by the vacuolar pigments, relative to flat petal epidermal cells (which appear pale and dull in comparison) (Kay, 1988;Kay et al, 1981;Noda et al, 1994). Flowers of Antirrhinum majus with conical epidermal cells are more attractive to pollinating bees than those with flat petal epidermal cells (Comba et al, 2000;.…”

Section: Introductionmentioning

confidence: 99%

Control of cell and petal morphogenesis by R2R3 MYB transcription factors

et al. 2007

View full text Add to dashboard Cite

Petals of animal-pollinated angiosperms have adapted to attract pollinators. Factors influencing pollinator attention include colour and overall size of flowers. Colour is determined by the nature of the pigments, their environment and by the morphology of the petal epidermal cells. Most angiosperms have conical epidermal cells, which enhance the colour intensity and brightness of petal surfaces. The MYB-related transcription factor MIXTA controls the development of conical epidermal cells in petals of Antirrhinum majus. Another gene encoding an R2R3 MYB factor very closely related to MIXTA, AmMYBML2, is also expressed in flowers of A. majus. We have analysed the roles of AmMYBML2 and two MIXTA-related genes, PhMYB1 from Petunia hybrida and AtMYB16 from Arabidopsis thaliana, in petal development. The structural similarity between these genes, their comparable expression patterns and the similarity of the phenotypes they induce when ectopically expressed in tobacco, suggest they share homologous functions closely related to, but distinct from, that of MIXTA. Detailed phenotypic analysis of a phmyb1 mutant confirmed the role of PhMYB1 in the control of cell morphogenesis in the petal epidermis. The phmyb1 mutant showed that epidermal cell shape affects petal presentation, a phenotypic trait also observed following re-examination of mixta mutants. This suggests that the activity of MIXTA-like genes also contributes to petal form, another important factor influencing pollinator attraction.KEY WORDS: Petal, Cell shape, Petunia, Antirrhinum, MYB transcription factor Development 134, 1691Development 134, -1701Development 134, (2007 DEVELOPMENT 1692Emerging data from the study of transcription factors belonging to large families of structurally related proteins suggest that very similar members of phylogenetically-clustered subgroups usually share closely related functions, even though functions may have diverged over the entire family. Structural similarity has led to claims of orthology and functional equivalence between MIXTA, PhMYB1 and AtMYB16 (van Houwelingen et al., 1998;Romero et al., 1998). However, to achieve a general understanding of the control of morphogenesis of petal epidermal cells, the function of new genes needs to be assayed and compared with that of the prototype, MIXTA. In addition, the relevance of these genes to cell shaping and, specifically, to their roles in adapting petals for pollinator attraction, needs to be established in different angiosperm species.We have examined the function of three of the genes encoding proteins very closely related to MIXTA; PhMYB1 from Petunia hybrida, AmMYBML2 from A. majus and AtMYB16 from Arabidopsis thaliana. Structurally, these proteins are most closely related to each other and their genes are therefore orthologous. All three proteins promote directional cell expansion in a bioassay in tobacco. The similarities between the phenotypes induced by these proteins in this bioassay (their biochemical functions) and the similarities in their expression patter...

show abstract

“…There are specialised conical cells on the adaxial surface (inner epidermis) of the petal lobes. The specialised shape of these cells optimises light capture by the pigments, causing the petal to appear deeper in colour, which increases the attractiveness of the flower to pollinating bees Comba et al, 2000). Petals have other epidermal cell types, including multicellular hairs (trichomes).…”

Section: Introductionmentioning

confidence: 99%

Development of three different cell types is associated with the activity of a specific MYB transcription factor in the ventral petal ofAntirrhinum majusflowers

et al. 2005

View full text Add to dashboard Cite

Petal tissue comprises several different cell types, which have specialised functions in pollination in different flowering plant species. In Antirrhinum majus, the MIXTA protein directs the formation of conical epidermal cells in petals. Transgenic experiments have indicated that MIXTA activity can also initiate trichome development, dependent on the developmental timing of its expression. MIXTA is normally expressed late in petal development and functions only in conical cell differentiation. However, an R2R3 MYB transcription factor very similar to MIXTA (AmMYBML1), which induces both trichome and conical cell formation in transgenic plants, is expressed very early during the development of the ventral petal. Its cellular expression pattern suggests that it fulfils three functions: trichome production in the corolla tube, conical cell development in the petal hinge epidermis and reinforcement of the hinge through differential mesophyll cell expansion. The DIVARICATA (DIV) gene is required for ventral petal identity. In div mutants, the ventral petal assumes the identity of lateral petals lacking these three specialised cell types, and expression of AmMYBML1 is significantly reduced compared with wild type, supporting the proposed role of AmMYBML1 in petal cell specification. We suggest that AmMYBML1 is regulated by DIV in association with the B-function proteins DEFICIENS and GLOBOSA, and,consequently, controls specification of particular cells within the ventral petal which adapt the corolla to specialised functions in pollination.

show abstract

The role of genes influencing the corolla in pollination of Antirrhinum majus

Abstract: ABSTRACT

Cited by 85 publications

References 20 publications

The interaction of temperature and sucrose concentration on foraging preferences in bumblebees

The interaction of temperature and sucrose concentration on foraging preferences in bumblebees

Control of cell and petal morphogenesis by R2R3 MYB transcription factors

Development of three different cell types is associated with the activity of a specific MYB transcription factor in the ventral petal ofAntirrhinum majusflowers

Contact Info

Product

Resources

About