Images: Thomas Eisner/Cornell University; © Cornell University
Talk about multi-tasking. A new study reveals that in the St. John’s Wort plant, Hypericum calycinum, the same chemical not only attracts pollinating insects but also deters herbivores that pose a threat to its survival. The findings appear in the current issue of the Proceedings of the National Academy of Sciences.
To the human eye, the flowers of H. calycinum appear as uniform yellow disks (top image). Insects with ultraviolet-sensitive eyes, however, see a dark, ultraviolet-absorbing center (bottom image), which acts as a bull’s-eye to help the insects narrow in on the nectar. According to the new research, one class of pigments responsible for this UV pattern is dearomatized isoprenylated phloroglucinols, or DIPs. The investigators also found high concentrations of DIPs on the plant’s reproductive structures, which suggest that the chemicals serve additional purposes in the plant. "Just as important as attracting pollinators to a plant is producing a viable seed," team member Matthew Gronquist of Cornell University explains, "so there is an evolutionary incentive to protect the reproductive apparatus from herbivores."
Indeed, the scientists found that hypercalin A, one of the DIPs isolated from H. calycinum, deterred larvae of the rattlebox moth. Those caterpillars unlucky enough to ingest the hypercalin A died. The researchers conclude that DIPs act simultaneously to draw pollinators and discourage predators. "Now that we know where to look," study co-author Thomas Eisner remarks, "antifeedant chemicals like the DIPs undoubtedly will be found in other plant species, and they offer clues to more natural insect control agents."
Sarah Graham | Scientific American
Biologists unravel another mystery of what makes DNA go 'loopy'
16.03.2018 | Emory Health Sciences
Scientists map the portal to the cell's nucleus
16.03.2018 | Rockefeller University
Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...
On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...
The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...
At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.
When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...
At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.
Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...
16.03.2018 | Event News
13.03.2018 | Event News
08.03.2018 | Event News
16.03.2018 | Earth Sciences
16.03.2018 | Physics and Astronomy
16.03.2018 | Life Sciences