Modulation of physiological and biochemical traits of two genotypes of Rosa damascena Mill. by SiO2-NPs under In vitro drought stress

Background Drought is a major abiotic stress that restricts plant growth and efficiency although some nutrients such as silicon improve drought tolerance by regulating the biosynthesis and accumulating some osmolytes. In this regard, a completely randomized factorial design was performed with three factors including two genotypes ('Maragheh' and 'Kashan'), three concentrations of silicon dioxide nanoparticles (SiO2-NPs) (0, 50, and 100 mg L- 1), and five concentrations of PEG (0, 25, 50, 75, and 100 g L- 1) with three replications. Results The findings showed that drought stress decreased protein content and it was improved by SiO2-NPs, so the genotype of 'Maragheh' treated with 100 mg L- 1 SiO2-NPs had the highest protein content. Under severe drought stress, had a higher membrane stability index (MSI) than 'Kashan', and the 'Maragheh' explants subjected to 100 mg L- 1 SiO2-NPs exhibited the uppermost MSI. The explants supplemented with 100 mg L- 1 SiO2-NPs sustained their photosynthetic parameters more in comparison with other treatments under drought stress conditions and as well as 100 mg L- 1 SiO2-NPs showed higher content of protein and proline of 'Maragheh' than 'Kashan'. Drought stress reduced Fm, Fv/Fm, and Fv, while SiO2-NPs treatment enhanced these parameters. SiO2-NPs also improved water deficit tolerance by enhancing the activity of antioxidant enzymes such as catalase (CAT), peroxidase (POD), guaiacol peroxidase (GPX), and superoxide dismutase (SOD) and reducing lipid peroxidation and H2O2 concentration. Conclusions According to the findings, the genotype 'Maragheh' was more tolerance to drought stress than 'Kashan' by improving water balance, antioxidant enzyme activities, and membrane stability as it was obtained from the unpublished previous evaluation in in vivo conditions and we concluded based on these results, in vitro culture can be used for drought screening in Damask rose plants. The results of the current study revealed that the induced drought stress by polyethylene glycol (PEG) in two Damask rose genotypes was ameliorated with SiO2-NPs and the tolerance genotypes were better than the sensitive ones in response to SiO2-NPs treatment.

Automated summary

This study found that silicon dioxide nanoparticles (SiO2-NPs) improved drought tolerance in Damask rose plants by regulating protein and osmolyte synthesis, enhancing membrane stability and photosynthetic parameters. Furthermore, SiO2-NPs also increased the activity of antioxidant enzymes, reducing lipid peroxidation and H2O2 concentration.