Alleviation of Nanoplastic Stress in Rice: Evidence from Biochemical, Cytological, Physiological, and Transcriptome Analysis

Nanoplastic (NP) pollution in terrestrial ecosystems is an emerging global concern, but little is known about its effects on crops and how to manage it. Here, we used two rice cultivars, S18 (from Oryza rufipogon) and MeiXiangZhan (MXZ) (cultivated rice), to study their tolerance against NP and the alleviation of NP through MoO3 nanoparticles (nMo). nMo was found to be capable of heteroaggregating with NP through SEM observation. Moreover, SEM and TEM showed that S18 exhibited a better-protected cellular structure than MXZ. Furthermore, physiological parameters, including photosynthetic pigments, antioxidant enzyme activities, lignin contents, Mo contents, along with H2O2 and MDA contents (decrease by 9 and 19% under nMo+NP compared to NP treatment), have shown that nMo was capable of alleviating NP stress, and S18 was better in maintaining physiological homeostasis. RNA-seq revealed that nMo and S18 activated signal transduction pathways and resistance-related genes under NP stress. Interestingly, PRX44 has a 4.95 log2FC of higher expression in S18 than in MXZ in NP. Overall, this research has provided insights into the future applications in enhancing stress resistance and mitigating NP in agricultural ecosystems. These two remedies were cost-effective and environmentally favorable, offering significant potential benefits for agricultural sustainability.