Cell size‐dependent species sensitivity to nanoparticles underlies changes in phytoplankton diversity and productivity

Abstract

Nanoparticle pollution has been shown to affect various organisms. However, the effects of nanoparticles on species interactions, and the role of species traits, such as body size, in modulating these effects, are not well‐understood. We addressed this issue using competing freshwater phytoplankton species exposed to copper oxide nanoparticles. Increasing nanoparticle concentration resulted in decreased phytoplankton species growth rates and community productivity (both abundance and biomass). Importantly, we consistently found that nanoparticles had greater negative effects on species with smaller cell sizes, such that nanoparticle pollution weakened the competitive dominance of smaller species and promoted species diversity. Moreover, nanoparticles reduced the growth rate differences and competitive ability differences of competing species, while having little effect on species niche differences. Consequently, nanoparticle pollution reduced the selection effect on phytoplankton community abundance, but increased the selection effect on community biomass. Our results suggest cell size as a key functional trait to consider when predicting phytoplankton community structure and ecosystem functioning in the face of increasing nanopollution.

Nanoparticles alter the nature and strength of intraploidy and interploidy interactions in plants

“…Consistent with the stress gradient hypothesis, intraploidy and interploidy competitions in the polyploid were weakened under nanoparticle stress, with a shift towards facilitation when growing with the diploid. This pattern aligns with observations from a limited number of studies investigating the impact of nanoparticles on species interactions (Peng et al, 2017;Wu et al, 2019;Menicagli et al, 2023;Zuo et al, 2024), where a reduction in competition has also been noted under nanoparticle exposure. For example, competitions between species of freshwater green micro-algae were found to decrease under CuO nanoparticles, contributing to species coexistence (Zuo et al, 2024).…”

“…This pattern aligns with observations from a limited number of studies investigating the impact of nanoparticles on species interactions (Peng et al, 2017;Wu et al, 2019;Menicagli et al, 2023;Zuo et al, 2024), where a reduction in competition has also been noted under nanoparticle exposure. For example, competitions between species of freshwater green micro-algae were found to decrease under CuO nanoparticles, contributing to species coexistence (Zuo et al, 2024). In ciliate protozoans, the interaction between Tetrahymena pyriformis and Loxocephalus sp.…”

“…The reduction in competition observed under CuO nanoparticles, but not bulk particles, suggests that the impact was attributable to nanoscale effects. The only other study that investigated the impact of CuO nanoparticles on species competitions in freshwater green micro-algae (Zuo et al, 2024) nevertheless did not include bulk particles to distinguish nanoscale effects vs. material effects. In line with our findings, stronger effects on species interactions under nanoparticles compared to bulk particles were observed in the ciliate protozoans under CeO 2 nanoparticles (Peng et al, 2017) and in the herbaceous Amaranthus plants under Ag nanoparticles (Wu et al, 2019).…”

“…It remains largely unknown whether the hypothesized polyploid advantage holds across various environmental conditions, particularly in the novel environments of the Anthropocene. These novel environmental conditions, including exposure to new pollutants like engineered nanoparticless, are likely to alter the nature and strength of species interactions (Peng et al, 2017; Wu et al, 2019; Menicagli et al, 2023; Zuo et al, 2024). Therefore, understanding species interactions in these novel environments is essential for predicting the future interactive dynamics of polyploid and diploid plants.…”

“…These include, for example, rice ( Oryza sativa ), maize ( Zea mays ), wheat ( Triticum aestivum ), soybean ( Glycine max ), cotton ( Gossypium hirsutum ), spinach ( Spinacia oleracea ), zucchini ( Cucurbita pepo ), sweet potato ( Ipomoea batatas ), and alfalfa ( Medicago sativa ) (Hong et al, 2015; Le Van et al, 2016; Singh and Kumar, 2016; Bradfield et al, 2017; Gao et al, 2018; Yusefi-Tanha et al, 2020; Roy et al, 2022). While these previous studies have revealed adverse effects of nanoparticles on individual organisms, such as reduced plant germination, nutrient uptake, and biomass (Rajput et al, 2017), it remains largely unknown how nanoparticle exposure influences species interactions (Peng et al, 2017; Wu et al, 2019; Menicagli et al, 2023; Zuo et al, 2024), especially in wild plants.…”