Breeding-mediated metabolic changes unexpectedly enhance petal blue fluorescence and shift the attractiveness of tea-oil Camelliato bees

Plant breeding has long focused on improving economic traits, yet its unintended effects on plant–pollinator interactions remain largely overlooked. Here, we report that selective breeding in Camellia oleifera unexpectedly enhances petal blue fluorescence, altering its attractiveness to bees. Field assays and behavioral experiments demonstrated that visual cues, rather than floral scents, play a decisive role in pollinator visitation, with bees showing a strong preference for petals emitting bright blue fluorescence under ultraviolet (UV) light. All six widely cultivated varieties exhibited stronger blue fluorescence than wild C. oleifera , in which the petals were nearly non-fluorescent. Metabolomic profiling revealed that the enhanced fluorescence correlated with the accumulation of hydroxycinnamic acid derivatives, particularly 3-O-p-coumaroylquinic acid. These compounds, originally targeted for improving fruit and oil quality, were found to mediate the formation of petal fluorescence and spatial patterning. This breeding-mediated metabolic shift effectively transformed C. oleifera from an “anti-bee” species into a “bee-attraction” species, suggesting a reversal of its natural pollination syndrome. Our findings uncover a previously unrecognized ecological consequence of plant breeding, linking secondary metabolism with pollination ecology. Recognizing and harnessing such floral traits in future breeding programs may not only improve pollination efficiency but also offer a novel pathway toward sustainable agroecosystem design.