Nanopriming with phytosynthesized zinc oxide nanoparticles for promoting germination and starch metabolism in rice seeds

• Published in: Journal of biotechnology Vol. 336; pp. 64 - 75
• Main Authors: Sharma, Deepa, Afzal, Shadma, Singh, Nand K.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 10-08-2021
• Subjects: Acquisition; Nanopriming; Nanotechnology; Rice; Senna; Zinc oxide nanoparticles; Nanopriming; Acquisition; Nanotechnology; Senna; Zinc oxide nanoparticles; Rice
• ISSN: 0168-1656; 1873-4863
• DOI: 10.1016/j.jbiotec.2021.06.014

•Zinc oxide nanoparticles (ZnO NPs) were synthesized at room temperature by leaf extract of Senna occidentalis.•The study explores the use of ZnO NPs as a nanopriming agent.•Nanopriming technique enhanced germination and other metabolic processes in BM6 rice seeds as compared to other priming methods.•Low concentration of nanopriming agent was found to be beneficial in germination enhancement in comparison to other treatments.•Enhanced level of zinc was reported in nanoprimed rice seeds that possibly increased nutritional value of seed by acquisition of zinc.
The application of zinc oxide nanoparticles (ZnO NPs) in agricultural field is emerging and relatively new. In this work, a simple, cost-efficient, non-toxic and eco-friendly method for the green synthesis of ZnO NPs by Senna occidentalis leaf extract has been described. Techniques used to characterize nanoparticles (NPs) were X-ray diffractometer (XRD), UV visible spectroscopy, Particle size analyzer (PSA), Fourier transform infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM). In this study, green synthesized ZnO NPs at 20−40 mg/l solution was used to prime aged seeds of early flowering homozygous mutant (BM6) of Pusa basmati (Oryza sativa), which enhanced germination performance and seedling vigor significantly as compared to zinc sulphate (ZnSO4) priming and conventional hydropriming. The effect of treatment was analyzed by measuring biophysical and biochemical parameter of germinating rice seeds. The seeds treated with ZnO NPs of 20 mg/l concentration showed more than 50 % stimulation in dry weight, relative water uptake of seeds and radicle length of seedling in comparison to other priming solution and control (hydro-primed). Significant growth was also observed in plumule length and fresh weight of seeds in ZnO NPs at 20 mg/l concentration in comparison to control and other priming treatments. At the same concentration of ZnO NPs, there was 23 % stimulation reported in total soluble sugar content and 45 % stimulation in amylase activity. There was also a substantial increase in antioxidant enzymes i.e. superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) activity. Seed priming represents an innovative user-friendly approach to enhance the germination rate, starch metabolic process and triggered zinc acquisition of rice aged seed as an alternative to the conventional priming method.