The activity of genes controlling organ development may be associated with the redox state of subregions within the meristem. Glutaredoxins react to the level of oxidative potential and can reduce cysteine dithiols, in some cases to activate specific transcription factors. In Arabidopsis, loss of function of the glutaredoxin ROXY1 or the trihelix transcription factor PETAL LOSS (PTL) each resul...

Abundance and visitation of pollinator assemblages tend to decrease with altitude, leading to an increase in pollen limitation. Thus increased competition for pollinators may generate stronger selection on attractive traits of flowers at high elevations and cause floral adaptive evolution. Few studies have related geographically variable selection from pollinators and intraspecific floral diffe...

Hydrangea (Hydrangea macrophylla) is tolerant of acidic soils in which toxicity generally arises from the presence of the soluble aluminum (Al) ion. When hydrangea is cultivated in acidic soil, its resulting blue sepal color is caused by the Al complex formation of anthocyanin. The concentration of vacuolar Al in blue sepal cells can reach levels in excess of approximately 15 mM, suggesting the...

The signal that initiates the age-regulated senescence program in flowers is still unknown. Here we propose for the ephemeral Arabidopsis thaliana flower that it dies because of continued expression of the MADS-box transcription factor AGAMOUS (AG). AG is necessary for specifying the reproductive structures of the flower. Flowers of ag-1, which lack AG, exhibited delayed sepal senescence and ab...

A new orchid species, Bulbophyllum pingnanense, is described and illustrated from Fujian, China. It is similar to Bulbophyllum brevipedunculatum and Bulbophyllum albociliatum in vegetative and floral morphology, but it can be distinguished from Bulbophyllum brevipedunculatum by having a longer dorsal sepal with longer white ciliate on margin, longer and lanceolate lateral sepals, and a glabrous...

Calolisianthus speciosus, an endemic species of cerrado and campos rupestres in Brazil, bears colleters both the leaf base sepal. These (leaf sepal) were anatomically compared to identify differences their structure secretion mechanism. Samples sepals leaves different development stages collected processed according standard methodologies for anatomical ultrastructural studies. Sepal similar, b...

In the Arabidopsis inflorescence meristem (IM), auxin is considered a prepatterning signal for floral primordia, whereas a centripetal mode of positional information for floral organ identity is inherent to the ABCE model. However, spatio-temporal patterns of organ initiation in each whorl at the earliest initiation stages are largely unknown. Evidence suggests that initial flower development o...

Petals, defined as the showy laminar floral organs in the second floral whorl, have been shown to be under similar genetic control in distantly related core eudicot model organisms. On the basis of these findings, it is commonly assumed that the petal identity program regulated by B-class MADS-box gene homologs is invariant across the core eudicot clade. However, the core eudicots, which compri...

Saffron production will be increased in arid regions by providing sufficient water through appropriate agronomic strategies. Therefore, in this investigation the impact of different rates of super absorbent polymer (SAP) including 0,10, 20, 30, 40 and 50 kg ha-1 was studied on saffron flowering traits during two growth cycles. Results showed that the influence of experimental factor was signifi...

Abstract Flower sepals are critical for flower development and vary greatly in life span depending on their function post-pollination. Very little is known about what controls sepal longevity. Using a senescence mutant screen, we identified two Arabidopsis mutants with delayed directly connecting strigolactones regulation novel floral context that hitherto has not been explored. The mutations w...