We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Responses of individual and combined polystyrene and polymethyl methacrylate nanoplastics on hormonal content, fluorescence/photochemistry of chlorophylls and ROS scavenging capacity in Lemna minor under arsenic-induced oxidative stress
Summary
Researchers exposed duckweed plants to polystyrene and polymethyl methacrylate nanoplastics under arsenic-induced stress and measured effects on hormones, photosynthesis, and antioxidant responses. They found that nanoplastics altered how plants responded to arsenic toxicity, with some combinations reducing oxidative damage while others worsened it. The study reveals that nanoplastic interactions with heavy metals in plants are complex and depend on the specific plastic type involved.
Nanoplastics alter the adverse impacts of hazardous contaminants such as heavy metals by changing their adsorption and accumulation. Few findings are available on the interaction between nanoplastic and heavy metals in plants. However, there is no report on the mechanisms for removing metal stress-mediated oxidative damage by the combination treatments of nanoplastics. To address this lack of information, polystyrene nanoplastic (PS, 100 mg L) and polymethyl methacrylate (PMMA, 100 mg L) were hydroponically applied to Lemna minor exposed to arsenate (As, 100 μM) for 7 days. PS or PMMA caused a reduction in the contents of N, P, K, Ca, Mg and Mn, but the improved contents were detected in the presence of PS or PMMA plus As stress. The hormone contents (auxin, gibberellic acid, cytokinin, salicylic acid and jasmonic acid) reduced by stress were re-arranged through PS or PMMA applications. Based on chlorophyll efficiency, fluorescence kinetics and performance of PSII, the impaired photosynthesis by As stress was improved via PS or PMMA applications. This alleviation did not continue under the combined form of PS and PMMA in As-applied plants. All analyzed antioxidant activity (superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), ascorbate peroxidase (APX), glutathione reductase (GR), glutathione S-transferase (GST), glutathione peroxidase (GPX), monodehydroascorbate reductase (MDHAR) and dehydroascorbate reductase (DHAR)) decreased or unchanged under As, PS or PMMA. Due to the inactivation of the defense system, L. minor had high levels of hydrogen peroxide (HO) and thiobarbituric acid reactive substances (TBARS), showing lipid peroxidation. After As toxicity, induvial applications of PS or PMMA indicated the activated enzyme capacity (SOD, POX, GST and GPX) and upregulated AsA/DHA, GSH/GSSG and redox state of GSH, which facilitated the removal of radical accumulation. The efficiency of the antioxidant system in As + PS + PMMA-applied L. minor was not enough to remove damage induced by As stress; hereby, TBARS and HO contents were similar to the As-treated group. Our findings from alone or combined application of PS and PMMA provide new information to advance the tolerance mechanism against As exposure in L. minor.
Sign in to start a discussion.
More Papers Like This
The adsorption of arsenic on micro- and nano-plastics intensifies the toxic effect on submerged macrophytes
Researchers investigated how arsenic adsorbs onto microplastics of varying types and sizes, and how those particles affect underwater plants. They found that nanoplastics increased arsenic absorption in aquatic macrophytes by 36-47%, causing more severe leaf damage and oxidative stress than either contaminant alone.
Single and combined toxicity of polystyrene nanoplastics and arsenic on submerged plant Myriophyllum verticillatum L.
Researchers investigated the combined toxicity of polystyrene nanoplastics and arsenic on the submerged aquatic plant Myriophyllum verticillatum. They found that nanoplastics reduced arsenic accumulation in the plant by 17 to 67 percent, and that the interaction between the two contaminants was dose-dependent, with nanoplastics alleviating arsenic toxicity at low doses but worsening it at higher concentrations. The study suggests that co-contamination of nanoplastics and heavy metals in freshwater environments may have complex ecological effects.
Nanoplastics in Duckweed: Single-Cell Responses and Recovery
This study investigated the effects of polystyrene nanoplastics on duckweed (Lemna) at the single-cell level, finding dose-dependent disruption of photosynthesis and oxidative stress responses. Notably, duckweed showed partial recovery after nanoplastic exposure ended, indicating some resilience in aquatic macrophytes.
The impacts of nanoplastic toxicity on the accumulation, hormonal regulation and tolerance mechanisms in a potential hyperaccumulator - Lemna minor L.
Researchers studied the toxic effects of polystyrene nanoplastics on the freshwater plant Lemna minor, a species used extensively in phytoremediation. The study found that nanoplastic exposure affected plant growth and triggered hormonal responses, while also revealing tolerance mechanisms that the plant employs to cope with nanoplastic stress.
Tissue-specific responses of duckweed to cadmium stress under nanoplastic co-exposure: differential accumulation and toxicity in roots and fronds
This study found that polystyrene nanoplastics promoted cadmium accumulation in duckweed roots while paradoxically reducing cadmium toxicity in the fronds, revealing tissue-specific differences in how nanoplastic co-exposure modifies metal toxicity in aquatic plants.