Meta-analysis of nanomaterials and plants interaction under salinity stress

Salinity stress threatens global food security, requiring novel and sustainable approaches for its mitigation. Over the past decade, nanomaterials (NMs) have emerged as a promising tool to mitigate salinity stress in plants. However, their use has been questioned in terms of whether they really benefit plants or are phytotoxic. Here, we specifically ask whether NMs can help ameliorate plant salinity stress. We use a multivariate meta-analysis of 495 experiments from 70 publications to assess how NMs interact with plants under salinity stress, with a focus on plant biomass accumulation and yield. We also analyzed the influence of NM type, dosage, application method, plant species and families, and growth media on the NM-plant interaction under salinity stress. We demonstrate that NMs enhance plant performance and mitigate salinity stress when applied at lower dosages. However, NMs are phytotoxic at higher dosages and may worsen salinity stress. Also, plant responses to NMs vary across plant species, families, and NM types. We propose a dose-dependent hypothesis to account for the effect of NMs on plant growth under salinity stress and highlight the knowledge gaps and research needs in this field.