Biology subjects

Bohman, B.

Publications and source records attributed to Bohman, B..

3 recordsLinked to original sources

bioRxiv2022

Critical pollination chemistry: Specific sesquiterpene floral volatiles in carrot inhibit honey bee feeding.

O_LIAlthough many plant species are reliant on insect pollination, agricultural plant breeding programs have primarily focused on traits that appeal to growers and consumers, rather than on floral traits that enhance pollinator attraction. In some vegetable seed production systems, this has led to declining pollinator attraction and poor seed yields. C_LIO_LIWe predicted that low-yielding crop varieties would be less attractive to pollinators due to deficiencies in nectar rewards or volatile floral attractants. To test our prediction, we used a chemical phenotyping approach to examine how floral chemical traits of five carrot lines affect honey bee visitation. C_LIO_LIIn bioassays, honey bees avoided feeders containing nectar from all carrot lines indicating a general non-attractant effect. Certain compounds in carrot flowers and nectar not only failed to elicit attraction but functioned as repellents, including the sesquiterpenes -selinene and {beta}-selinene. Others enhanced attraction, e.g. {beta}-ocimene. C_LIO_LIThe repellent sesquiterpenes have previously been implicated in plant defense suggesting a fine balance between pollination and plant protection, which when disrupted in artificial selection in plant breeding programs can impact the crop yield. These new insights highlight the importance of bioactive compounds in attracting pollinators toward floral resources in both ecological and agricultural settings. C_LI

plant biology↗

bioRxiv2021

A pathogenic fungus uses volatiles to entice male flies into fatal matings with infected female cadavers

To ensure dispersal, many parasites and pathogens behaviourally manipulate infected hosts. Other pathogens and certain insect-pollinated flowers use sexual mimicry and release deceptive mating signals. However, it is unusual for pathogens to rely on both behavioural host manipulation and sexual mimicry. Here, we show that the host-specific and behaviourally manipulating pathogenic fungus, Entomophthora muscae, generates a chemical blend of volatile sesquiterpenes and alters the level of natural host cuticular hydrocarbons in dead infected female house fly (Musca domestica) cadavers. Healthy male house flies respond to the fungal compounds and are enticed into mating with dead female cadavers. This is advantageous for the fungus as close proximity between host individuals leads to an increased probability of infection. The fungus-emitted volatiles thus represent the evolution of an extended phenotypic trait that exploit male flies willingness to mate and benefit the fungus by altering the behavioural phenotype of uninfected healthy male host flies.

microbiology↗

bioRxiv2020

The human odorant receptor OR10A6 is tuned to the pheromone of the commensal fruit fly Drosophila melanogaster

BackgroundAll living things speak chemical. The challenge is to discover the vocabulary, the volatile odorant chemicals that enable communication across phylogenies and to translate them to physiological, behavioural and ecological function. Olfactory receptors (ORs) interface animals with airborne odorants. Expression of single ORs in human embryonic kidney cells (HEK-293) makes it possible to interrogate ORs with synthetic chemicals and to identify cognate ligands that convey olfactory information. ResultsThe cosmopolitan strain of the vinegar fly Drosophila melanogaster has accompanied the human expansion out of Africa, more than ten thousand years ago. These flies are strictly anthropophilic and depend on human resources and housing for survival, particularly in colder climate zones. Curiously, humans sense the scent of a single fly, and more precisely the female pheromone (Z)-4 undecenal (Z4-11Al), at 10 ng/mL (0.06 {micro}mol/L). A screening of all functional human ORs in a HEK-293 assay provides an explanation for this astounding sensitivity, as it shows that OR10A6, one of the most highly expressed human ORs, is specifically tuned to Z4-11Al. Chemical analysis of fly effluvia confirms that cosmopolitan D. melanogaster females release Z4-11Al, while females of an African fly strain from Zimbabwe release a 1:3-blend of Z4-11Al and (Z)-4 nonenal (Z4-9Al). Interestingly, a blend of Z4-9Al and Z4-11Al produces a different aroma than the the single compounds, which is why we readily differentiate cosmopolitan and Zimbabwe flies by nose. ConclusionThat we sensitively and specifically perceive the fly pheromone Z4-11Al suggests that it is a component of human odour scenes. This may have afforded a sensory drive during adaptation of commensal flies to human habitats and selected for a role of Z4-11Al in fly aggregation and premating communication. Screening ORs for key ligands leads to the discovery of messenger chemicals that enable chemical communication among and betwen vertebrate and invertebrate animals.

animal behavior and cognition↗