Flowers in the genusPetuniarely on a variety of pollinators , cast from bees to hummingbirds to moth . Researchers have now identified a single factor that seems to control which pollinators specific petunia species draw . Mutations on this gene bear on the flower ’s ability to absorb ultraviolet light , an significant trait for attracting nocturnal pollinators , according to findings published inNature Geneticsthis week .
anthesis plants often depend on animal pollinators , and these partnerships are typically associated with specific sets of floral traits cross a diversity of colour , scents , shapes , and ambrosia type . Over evolutionary time , plants can acquire changes that tolerate them to attract new pollinator , but adaptation to new pollinators – and the speciation case that might follow – are rather tortuous processes requiring multiple flowered traits as well as coordinated changes in the underlying factor .
Despite this complexity , it ’s happened frequently over the history of flowering plants . The conversion from bee to hummingbird pollenation has occurred at least 10 time in the nightshade family alone .
To analyze how flora evolve new pollinator partnerships , the University of Bern’sCris Kuhlemeierand colleagues looked at the molecular basis of UV light source absorbance in three specie of South American petunias , a phallus of the nightshade family . The most ancestral of the three , Petunia inflata , has pocket-size , purplish flower that are pollinated by solitary bees . The bright red , non - odoriferous flowers ofP. exsertaattract hummingbirds in the daylight , and the white-hot prime ofP. axillarisattract hawkmoths at Nox .
Out of these three petunia species , whiteP. axillarisflowers absorb the highest grade of UV illumination . And their raw hawkmoth pollinators , Manduca sexta , prefer bloom that absorb higher degree of UV light over those with lower levels of absorbance . UV - reflective flowers get fewer visit from these moths .
The differences in UV photographic density that germinate in the diverging petunia species are due to changes in a single gene call MYB - FL . The shift from bee pollenation in the ancestral grade to hawkmoth pollination inP. axillariswas accompanied by a mutant in MYB - FL that up the grade of UV - absorbing compounds called flavonols within the blossom flower petal . Later on , a different chromosomal mutation rise that disabled MYB - FL , and this led to the shift from hawkmoth pollination to the daytime services of hummingbirds forP. exserta .
A flower bear witness in seeable light source ( left ) , and a flower shown in ultraviolet light visible light ( right ) . Hester Sheehan
