Epigenetic Modifications and Gene Expression Alterations in Plants Exposed to Nanomaterials and Nanoplastics: The Role of MicroRNAs, lncRNAs and DNA Methylation

Nanomaterials (NMs) are currently widely used in a wide range of industrial production and scientific applications, starting from molecular and medical diagnostics to agriculture. In the agricultural and food systems, NMs are now used in various ways, to improve the nutritional value of crops, detect microbial activity and inhibit biofilms, encapsulate and deliver pesticides, protect plants from chemical spoilage, as nanosensors and more. Despite these applications, NMs are described as “dual-face technologies”: they can also act as environmental contaminants. For instance, nanoplastics (NPs) dispersed in the environment can damage plants at different levels and undermine their viability. Epigenetic modifications induced by NMs have potentially wider and longer-term impacts on gene expression and plant functions. Therefore, it is important to verify whether plants are also affected by NMs on the molecular level, including epigenetic mechanisms and any induced variation on the epigenome. This review focusses on gene expression modulation and epigenetic alterations such as DNA methylation and the role of microRNAs and long non-coding RNAs (lncRNAs) induced in plants and crops by NMs and NPs.