Proteomics study of silver nanoparticles toxicity on Oryza sativa L.

Nanoparticles Alter Secondary Metabolism in Plants via ROS Burst

“…Whereas, dehydroascorbate reductase (DHAR) and monodehydroascorbate reductase (MDAR) enzymes that regulate the cellular Asc redox state were downregulated (Fu et al, 2014). Proteomic analysis of AgNPs treated O. sativa roots revealed an increased abundance of SOD, APX, and glutathione- S -transferase (GST) (Mirzajani et al, 2014). These NPs also stimulated the activities of SOD and APX significantly, while inhibiting glutathione reductase (GR) and DHAR in Pisum sativum L. seedlings (Tripathi et al, 2017).…”

“…Recognition of AgNPs by plasma membrane bound receptors triggered a Ca 2+ burst and ROS induction in A. thaliana (Sosan et al, 2016). Ca 2+ levels and associated signaling pathway proteins were found to be upregulated in the proteomic analysis of AgNP treated O. sativa roots (Mirzajani et al, 2014). These authors hypothesized that AgNPs, or ions released thereof, impede cell metabolism by binding to Ca 2+ receptors, Ca 2+ channels, and Ca 2+ /Na + ATPases.…”

“…Although the accumulation of NPs in chloroplasts and damage to the photosynthetic apparatus (Da Costa and Sharma, 2016; Jiang et al, 2017) supports the former, the fact that to reach the chloroplast NPs must cross the plasma membrane, where they can induce reactive oxygen species (ROS) via NADPH oxidases (Sosan et al, 2016) argues the reverse. ROS production, damage to the membrane structure and function, and fluctuation in antioxidant enzymatic activities are documented across plant species as common responses to NPs (Thwala et al, 2013; Vannini et al, 2013; Fu et al, 2014; Mirzajani et al, 2014; Hossain et al, 2015; Xia et al, 2015; Jiang et al, 2017; Tripathi et al, 2017). A few studies have also demonstrated that treatment of plants and photosynthetic microorganisms with NPs resulted in increased production of phenolics (Comotto et al, 2014; Ghorbanpour and Hadian, 2015; Večeřová et al, 2016), which might act as antioxidants to scavenge the ROS (Dixon and Paiva, 1995; Franklin et al, 2009).…”

Interactions between nanoparticles and plants: phytotoxicity and defense mechanisms

“…It was found that 10 mg/L Ag NPs caused the alteration of all sorts of proteins which are vastly related to cell metabolism (Vannini et al 2014). Likewise, according to Mirzajani et al (2014), exposure of Oryza sativa L. to Ag NPs led to the identification of 28 responsive proteins, for example, decrement/increment in abundance, which were involved in various important physiological and biochemical processes, for example, Ca 2+ regulation and signaling, oxidative stress tolerance, cell wall and RNA/DNA/protein direct damage, transcription and protein degradation, ultimately leading to cell division and apoptosis. Hossain et al (2016) evaluated the phytotoxicity of Al 2 O 3 , ZnO and Ag NPs in soybean seedlings at the proteome level; 16 common proteins in soybean leaves were significantly changed, which were predominantly associated with protein degradation and photosystem.…”

Nanotechnology a Potential Tool to Mitigate Abiotic Stress in Crop Plants

“…The transcriptional response of Arabidopsis plants exposed to Ag NPs was analyzed using whole-genome cDNA expression microarrays [55] which result in upregulation of 286 genes, including the genes primarily associated with metal and oxidative stress (e.g., vacuolar cation/proton exchanger, superoxide dismutase, cytochrome P450-dependent oxidase, and peroxidase), and down regulation of 81 genes, including the genes involved in plant defense system and hormonal stimuli (e.g., auxin-regulated gene involved in organ size-ARGOS, ethylene signaling pathway, and SAR against pathogens). On the other hand, the effects of silver nanoparticles on proteomic study of rice that reveals silver nanoparticles responsive proteins were primarily associated with oxidative stress response pathway, Ca 2+ regulation and signaling, transcription, protein degradation, cell wall synthesis, cell division, and apoptosis [56]. The effect of zinc oxide (nZnO) in Arabidopsis thaliana [57], fullerene soot (FS) or titanium dioxide (nTiO 2 ) nanoparticles on gene expression in roots and resulted in 660 up-and 826 down-regulated genes, 232 up-and 189 downregulated genes, and 80 up-and 74 down-regulated genes, respectively (expression difference > 2-fold).…”