Transgenerational effects of stress on reproduction strategy in the mixed mating plant Lamium amplexicaule.

Background: The theory of Condition Dependent Sex predicts that - everything else being equal - less fit individuals would outcross at higher rates compared with fitter ones. Here we used the mixed mating plant Lamium amplexicaule, capable of producing both self-pollinating closed flowers (CL), alongside open flowers (CH) that allow cross pollination to test it. We investigated the effects of abiotic stress - salt solution irrigation - on the flowering patterns of plants and their offspring.

Flowers respond to pollinator sound within minutes by increasing nectar sugar concentration.

Can plants sense natural airborne sounds and respond to them rapidly? We show that Oenothera drummondii flowers, exposed to playback sound of a flying bee or to synthetic sound signals at similar frequencies, produce sweeter nectar within 3 min, potentially increasing the chances of cross pollination. We found that the flowers vibrated mechanically in response to these sounds, suggesting a plausible mechanism where the flower serves as an auditory sensory organ. Both the vibration and the nectar response were frequency-specific: the flowers responded and vibrated to pollinator sounds, but not to higher frequency sound.

Less fit Lamium amplexicaule plants produce more dispersible seeds.

Theory predicts that less fit individuals would disperse more often than fitter ones (Fitness Associated Dispersal, FAD hypothesis). To test this prediction under laboratory conditions, an entire life cycle of Lamium amplexicaule plants and the preferences of its dispersal agent, Messor ebeninus ants, were tracked. Characterization of individual L.