Nano-WSe₂ Is Absorbable and Transformable by Rice Plants.

Area of Science:

• Environmental Science
• Materials Science
• Plant Biology

Background:

• Transition metal dichalcogenides (TMDCs) like tungsten selenide (WSe2) nanosheets are increasingly used, leading to environmental release of tungsten (W) and selenium (Se).
• The environmental impact of WSe2 nanomaterials on plants remains largely unknown, necessitating research into their effects and fate in agricultural systems.

Purpose of the Study:

• To investigate the impacts and environmental fate of nano-WSe2 and micro-WSe2 in rice plants (Oryza sativa L.).
• To assess the effects of WSe2 exposure on rice seed germination, seedling growth, and physiological responses.

Main Methods:

• Rice seeds and seedlings were exposed to varying concentrations of nano-WSe2 and micro-WSe2.
• Plant growth parameters, including germination and root length, were measured.
• The uptake, translocation, and chemical transformation of W and Se within rice plants were analyzed.

Main Results:

• Neither nano-WSe2 nor micro-WSe2 affected rice seed germination up to 5000 mg/L.
• Nano-WSe2 exposure resulted in significantly shortened root lengths and induced lipid peroxidative damage in rice seedlings.
• WSe2 uptake and translocation were size-dependent, with W transforming to tungstate and Se to various selenocompounds in rice roots.

Conclusions:

• Nano-WSe2 poses risks to rice plant growth and causes oxidative stress, highlighting environmental safety concerns associated with TMDC applications.
• The size-dependent uptake and transformation of WSe2 in rice indicate complex environmental interactions that require further investigation.
• This study provides the first comprehensive report on the ecotoxicological effects and fate of nano-WSe2 in rice plants.