RESUMEN
In the recent years, nanotechnology has attained much attention in the every field of science. The synthesis, characterisation and applications of metallic nanoparticles (MNPs) have become an important branch of nanotechnology. In the current study, MNPs were synthesised through polyols process and applied in vitro to study their effect on medicinally important plant : Artemisia absinthium. The current study strives to check the effect of MNPs, i.e., Ag, Cu and Au on seed germination, root and shoot length, seedling vigour index (SVI) and biochemical profiling in A. absinthium. The seeds were inoculated on MS medium supplemented with various combinations of MNPs suspension. The seed germination was greatly influenced upon the application of MNPs and was recorded highest for the silver nanoparticles (AgNPs) suspensions. The best result for seed germination (98.6%) was obtained in MS medium supplemented with AgNPs as compared to control (92.9%) and other nanoparticles, i.e., copper (69.6%) and gold (56.5%), respectively, after 35 days of inoculation. Significant results were obtained for root length, shoot length and SVI in response to application of AgNPs as compared to copper nanoparticles (CuNPs) and gold nanoparticles (AuNPs). These nanoparticles (NPs) could induce stress in plants by deploying the endogenous mechanism. In response to these stresses, plants produce various defence compounds. Total phenolic content (TPC) and total flavonoid content (TFC) were significant in the MS medium supplemented with AgNPs as compared to other NPs, while DPPH radical scavenging assay (RSA) was highest in AuNPs treated plantlets. The MNPs showed higher toxicity level and enhanced secondary metabolites production, total phenolic content, total flavonoid content, antioxidant activity, superoxide dismutase (SOD) activity and total protein content.
RESUMEN
UNLABELLED: Aluminum oxide nanoparticles (Al2O3 NPs) are used in various commercial and agricultural products. Soybean exhibits severe reduction in growth under flooding condition. To examine the effects of Al2O3 NPs on the recovery of soybean from flooding, proteomic analysis was performed. Survival percentage and weight/length of root including hypocotyl were improved after 2 and 4days of flooding with 50ppm Al2O3 NPs leading to recovery as compared to flooding. A total of 211 common proteins were changed in abundance during the recovery period after treatment without or with Al2O3 NPs. These proteins were related to protein synthesis, stress, cell wall, and signaling. Among the identified stress-related proteins, S-adenosyl-l-methionine dependent methyltransferases were recovered from flooding with Al2O3 NPs. Hierarchical clustering divided the identified proteins into three clusters. Cluster II exhibited the greatest change in proteins related to protein synthesis, transport, and development during the recovery from flooding with Al2O3 NPs. However, activity of enolase remained unchanged during flooding leading to subsequent recovery with Al2O3 NPs. These results suggest that S-adenosyl-l-methionine dependent methyltransferases and enolase might be involved in mediating recovery responses by Al2O3 NPs. BIOLOGICAL SIGNIFICANCE: This study highlighted the role of Al2O3 NPs in recovery of soybean seedlings from flooding stress using gel-free proteomic technique. The key findings of this study are as follows: (i) survival percentage was enhanced at 50ppm Al2O3 NPs during the recovery stage; (ii) seedling weight and weight/length of root including hypocotyl improved at 50ppm Al2O3 NPs during the period of recovery; (iii) protein synthesis and stress related proteins were increased on recovery after flooding without or with Al2O3 NPs; (iv) the abundance of S-adenosyl-l-methionine dependent methyltransferases recovered from flooding with Al2O3 NPs; (v) glycolysis related proteins amplified under flooding with Al2O3 NPs; (vi) enolase enzyme remained unchanged during flooding leading to subsequent recovery from flooding with Al2O3 NPs. Collectively, these results suggest that S-adenosyl-l-methionine dependent methyltransferases and enolase are involved in response to flooding with Al2O3 NPs and might be helpful in recovery from flooding stress.