A comprehensive study of the hormetic influence of biosynthesized AgNPs on regenerating rice calli of indica cv. IR64

Abstract

Rice is one of the most widely cultivated crops worldwide; however, it is not amenable to genetic manipulations, owing to its poor response to tissue culture and regeneration in vitro . To improve its response to tissue culture, we evaluated the influence of biosynthesized silver nanoparticles on callus induction, regeneration and rhizogenesis in Indica rice cv. IR64. Silver nanoparticles were biosynthesized by using silver nitrate and Parthenium hysterophorus plant extract, and were characterized by UV-visible spectroscopy, Fourier-transform infrared spectroscopy, Transmission electron microscopy and X-ray diffraction. The biosynthesized silver nanoparticles (PHAgNPs), when supplemented in tissue culture medium, promoted callus induction frequency, callus regeneration and rhizogenesis at concentrations of 10 mg l −1 , 5 mg l −1 and 10 mg l −1 , respectively. Further examination of the endogenous hormonal levels in regenerating calli revealed that AgNPs enhanced regeneration by alleviating abscisic acid and ethylene levels in the plant tissue. The stimulatory influence eliciting the regeneration response was found to be optimal with the supplementation of 5 mg l −1 PHAgNPs in the regeneration medium; the malondialdehyde, proline and hydrogen peroxide levels were also lower than those in the control, thus suggesting improved antioxidant status. Our results indicated that biosynthesized PHAgNPs may have the potential to positively influence tissue culture of recalcitrant varieties.

Exploring potential of copper and silver nano particles to establish efficient callogenesis and regeneration system for wheat (Triticum aestivumL.)

“…It reveals that fortification of tissue culture media with silver nanoparticles (AgNPs) improves vigor and regeneration frequency of explants, mainly because of higher ability of silver ions to inhibit ethylene biosynthesis. 43 , 50 , 71 Manickavasagam et al 72 reported that biosynthesized silver nanoparticles when supplemented in tissue culture media promote callus induction frequency, callus regeneration and rhizogenesis along with significant decrease in concentration of reactive oxygen species, hydrogen peroxide and malondialdehyde in Menthalongi folia . A significant increase in callus induction and callus growth rate of Phaseolus vulgaris is reported in response to exposure of explants to 50 mg/l AgNPs for 30 min, while higher concentration were found detrimental for callogenesis.…”

Nanotechnology in Plant Metabolite Improvement and in Animal Welfare

“…The effect of AgNPs' was also investigated in callus induction of Oryza sativa cv. IR64; where the highest callus induction was observed at a relatively low concentration of AgNPs [47]. The callus induction increased significantly as compared to that in the control medium.…”

“…Another possible mechanism of growth stimulation mediated by AgNPs, can be ascribed to PGR-responsive gene expressions. As a matter of fact, investigations demonstrated that these nanoparticles decreased the expression of ethylene-and ABA-responsive genes, resulting in callus regeneration rate [47]. Under closed container culture conditions, plant development will be highly influenced by self-produced gases, such as ethylene, which possibly regulate senescence.…”

Biogenic iron oxide nanoparticles enhance callogenesis and regeneration pattern of recalcitrant Cicer arietinum L.

“…m 2 /s, 16/8 h photoperiod) conditions at 25±2°C for 14 days. After a cultivation period of 13–16 days, embryogenic callus induced from explants were achieved [ 32 ]. Callus induction frequency was calculated using the following formula: …”

“…SRMI (MS+ 0.5mg/L BAP), SRMII (MS+ 1 mg/L BAP+ 0.5 mg/L Kn) supplemented with different concentrations of IONPs (1–20 mg/L) and without IONPs as control. The regeneration frequency was observed as the percentage of chickpea explants respond to the development of shoot after 14 days [ 32 ]. The regeneration frequency was calculated using the formula given below: …”