Polystyrene microplastics decrease dibutyl phthalate uptake and metabolism in pumpkins.

Area of Science:

• Environmental Science
• Plant Biology
• Toxicology

Background:

• Environmental impact of polystyrene (PS) and dibutyl phthalate (DBP) is a growing concern.
• Limited research exists on their combined effects on higher plants.

Purpose of the Study:

• Investigate the combined toxicity of different sizes and concentrations of PS and DBP on pumpkins.
• Assess how PS influences DBP absorption and metabolism in plants.

Main Methods:

• Exposure of pumpkins to varying concentrations of PS (100 and 300 nm) and DBP.
• Measurement of DBP content, plant biomass, and key enzyme activities (carboxylate esterase, dehydrogenase, RuBisCO).
• Analysis of oxalic acid secretion and root activity.

Main Results:

• 100 nm PS and DBP exhibited synergistic toxicity, while 300 nm PS showed antagonism.
• PS reduced DBP uptake and metabolism, linked to increased oxalic acid and decreased root/enzyme activity.
• Both PS and DBP reduced pumpkin biomass, with specific impacts on root and leaf growth.

Conclusions:

• Combined exposure to PS and DBP poses significant risks to pumpkin plants.
• The size of PS nanoparticles critically influences their interaction with DBP toxicity.
• Findings suggest potential strategies, like using arginine, for remediation in microplastic-contaminated environments.