Environmentally-relevant concentrations of dissolved sucralose affect gas exchange, chlorophyll content, and flowering hue of three North American prairie species.

Abstract

Consumers are ingesting and excreting extraordinary amounts of non-nutritive sweeteners (NSs) which, because they are not metabolized, enter surface- and groundwater systems. Furthermore, agricultural animal feed often contains NSs that become concentrated in manure and subsequently spread on fields as fertilizer. With both fertilizer and irrigation waters introducing NSs into terrestrial soils, NSs are now classified as a contaminant of emerging concern, highlighting the need to study their potential ecotoxicological effects. Here, we investigated the impact of sucralose on the gas exchange, chlorophyll content, and floral color patterns of three North American wildflowers: black-eyed Susans (Rudbeckia hirta), cardinal flower (Lobelia cardinalis), and purple cone flowers (Echinacea purpurea). Even an environmentally-miniscule concentration of sucralose (10 μg L-1) resulted in altered gas exchange, lower water use efficiency, and significantly lower chlorophyll concentrations in most of these species. Furthermore, sucralose altered the flowering hue of R. hirta, suggesting that NSs might impact plant-pollinator interactions. Our results suggest that the ever-increasing prevalence of NSs in our surface and groundwater systems might pose a significant threat to agricultural and ecological systems by altering plant physiology and flower morphology.