Abstract
While the antimicrobial activity of silver nanoparticles (AgNPs) is well established, the phytostimulatory and/or phytotoxic influences of AgNPs in closed tissue culture vessels is more controversial, to some extent. This is because numerous research papers have been published that ultimately conclude apparently contradictory results. In this paper, the physiological responses which AgNPs induce are studied in both tobacco micro-shoots and tobacco seedlings via the utilization of a number of morphological, biochemical, and molecular approaches. This report provides direct evidence that AgNPs positively regulate growth response in tobacco via a curtailing of ethylene production and an inhibition of the general ethylene signaling pathway. Tobacco seedlings exposed to media supplemented with high concentrations of AgNPs (150 μg mL−1) were shown to exhibit a hypersensitivity response. However, when compared to the control, tobacco seedlings exposed to sub-lethal concentrations of AgNPs (50 μg mL−1) displayed increased leaf fresh weight and plant height, as well as a 6-fold increase to root length. Inductively coupled plasma mass spectrometry (ICP-MS) confirmed the presence of silver ions (Ag+) in AgNP-treated tobacco leaves, and given that silver is known to be a potent inhibitor of ethylene action, this result led us to question whether AgNPs might be inhibiting ethylene receptor expression. Subsequent qRT-PCR testing in tobacco tissue treated with 50 μg mL−1 AgNP revealed a downregulation of ETR1, ERS1, and CTR1, which are all key ethylene signaling genes, as well as a downregulation of an important downstream ethylene-synthesizing gene, ACS2. This clearly established that the increase to root length in response to AgNPs might be occurring via an AgNP-dependent suppression of ethylene signaling genes. Further, gas chromatography analysis confirmed that tobacco planted on media supplemented with sub-lethal concentrations of AgNPs exhibited a reduction of gaseous ethylene production in closed in vitro vessels. Plants exposed to a higher concentration of AgNPs in their media did not show any additional inhibitory effects, with regard to ethylene production. Nonetheless, ultimately, the collective data implies that AgNPs inhibit various aspects of the ethylene signaling pathway, in addition to inhibiting the production of ethylene itself, and both of these inhibitions occur in a dose-dependent manner.
Similar content being viewed by others
References
Aebi H (1984) Catalase in vitro in methods in enzymology. Academic press 105:121–126
Afshinnia K, Gibson I, Merrifield R, Baalousha M (2016) The concentration-dependent aggregation of Ag NPs induced by cysteine. Sci Total Environ 557-558:395–403
Aghdaei M, Salehi H, Sarmast MK (2012) Effects of silver nanoparticles on Tecomella undulata (Roxb.) Seem. micropropagation. Adv Hortic Sci 26:21–24
Azeez L, Lateef A, Wahab AA, Rufai MA, Salau AK, Ajayi EIO, Ajayi M, Adegbite MK, Adebisi B (2018) Phytomodulatory effects of silver nanoparticles on Corchorus olitorius: its antiphytopathogenic and hepatoprotective potentials. Plant Physiol Biochem 136:109–117
Baalousha M, Nur Y, Römer I, Tejamaya M, Lead JR (2013) Effect of monovalent and divalent cations, anions and fulvic acid on aggregation of citrate-coated silver nanoparticles. Sci Total Environ 454-455:119–131
Beyer EM Jr (1976) A potent inhibitor of ethylene action in plants. Plant Physiol 58:268–271
Chance В, MA (1955) Assay catalase and peroxidase. Methods in Enzymology. Academic Press, New York, pp 764–775
Cui D, Zhang P, Ma Y, He X, Li H, Zhao Y, Zhang Z (2014) Phytotoxicity of silver nanoparticles to cucumber (Cucumis sativus) and wheat (Triticum aestivum). J Zhejiang Univ Sci A 15:662–670
Cvjetko P, Zovko M, Štefanić PP, Biba R, Tkalec M, Domijan AM, Vrček IV, Letofsky-Papst I, Šikić S, Balen B (2018) Phytotoxic effects of silver nanoparticles in tobacco plants. Environ Sci Pollut Res 25:5590–5602
Dhindsa RS, Plumb-Dhindsa P, Thorpe TA (1981) Leaf senescence: correlated with increased levels of membrane permeability and lipid peroxidation, and decreased levels of superoxide dismutase and catalase. J Exp Bot 32:93–101
Eapen S, George L (1997) Plant regeneration from peduncle segments of oil seed Brassica species: influence of silver nitrate and silver thiosulfate. Plant Cell Tiss Org Cult 51:229–232
Gondikas AP, Morris A, Reinsch BC, Marinakos SM, Lowry GV, Hsu-Kim H (2012) Cysteine-induced modifications of zero-valent silver nanomaterials: implications for particle surface chemistry, aggregation, dissolution, and silver speciation. Environ Sci Technol 46:7037–7045
Gupta SD, Agarwala A, Pradhan S (2018) Phytostimulatory effect of silver nanoparticles (AgNPs) on rice seedling. growth: an insight from antioxidative enzyme activities and gene expression patterns. Ecotoxicol Environ Saf 161:624–633
Huang SY, Chan HS, Wang TT (2006) Induction of somatic embryos of celery by control of gaseous compositions and other physical conditions. Plant Growth Regul 49:219–227
Jiang M, Zhang J (2002) Involvement of plasma-membrane NADPH oxidase in abscisic acid-and water stress-induced antioxidant defense in leaves of maize seedlings. Planta 215:1022–1030. https://doi.org/10.1007/s00425-002-0829-y
Kaveh R, Li YS, Ranjbar S, Tehrani R, Brueck CL, Van Aken B (2013) Changes in Arabidopsis thaliana gene expression in response to silver nanoparticles and silver ions. Environ Sci Technol 47:10637–10644
Kazemipour S, Hashemabadi D, Kaviani B (2013) Effect of silver nanoparticles on the vase life and quality of cut chrysanthemum (Chrysanthemum morifolium L.) flower. Euro J Exp Biol 3:298–302
Ke M, Qu Q, Peijnenburg WJGM, Li X, Zhang M, Zhang Z, Lu T, Pan X, Qian H (2018) Phytotoxic effects of silver nanoparticles and silver ions to Arabidopsis thaliana as revealed by analysis of molecular responses and of metabolic pathways. Sci Total Environ 644:1070–1079
Kevers C, Boyer N, Courduroux J-C, Gaspar T (1992) The influence of ethylene on proliferation and growth of rose shoot cultures. Cell Tiss Org Cult 28:175–181
Lewis DR, Negi S, Sukumar P, Muday GK (2011) Ethylene inhibits lateral root development, increases IAA transport and expression of PIN3 and PIN7 auxin efflux carriers. Development 138:3485–3495
Li w, Ma M, Feng Y, Li H, Wang Y, Ma Y, Li M, An F, Guo H (2015) EIN2-directed translational regulation of ethylene signaling in Arabidopsis. Cell 163:670–683
Liu J, He S, Zhang Z, Cao J, Lv P, He S, Cheng G, Joyce DC (2009) Nano-silver pulse treatments inhibit stem-end bacteria on cut gerbera cv. Ruikou flowers. Postharvest Biol Technol 54:59–62
Livak KJ, Schmittgen TD (2001) Analysis of relative gene expression data using real-time quantitative PCR and the 2-∆∆CT method. Methods 25:402–408
Lü P, Cao J, He S, Liu J, Li H, Cheng G, Ding Y, Joyce DC (2010) Nano-silver pulse treatments improve water relations of cut rose cv. Movie Star flowers. Postharvest Biol Technol 57:196–202
Mahmoud LM, Grosser JW, Dutt M (2020) Silver compounds regulate leaf drop and improve in vitro regeneration from mature tissues of Australian finger lime (Citrus australasica). Plant Cell Tiss Org 141:455–464. https://doi.org/10.1007/s11240-020-01803-8
Marambio-Jones C, Hoek EM (2010) A review of the antibacterial effects of silver nanomaterials and potential implications for human health and the environment. J Nanopart Res 12:1531–1551
Martin KP (2002) Rapid propagation of Holostemma ada-kodien Schult., a rare medicinal plant, through axillary bud multiplication and indirect organogenesis. Plant Cell Rep 21:112–117
Merchante C, Alonso JM, Stepanova AN (2013) Ethylene signaling: simple ligand, complex regulation. Curr Opin Plant Biol 16:554–560
Mirzajani F, Askari H, Hamzelou S, Farzaneh M, Ghassempour A (2013) Effect of silver nanoparticles on Oryza sativa L. and its rhizosphere bacteria. Ecotoxicol Environ Saf 88:48–54
Mitchell CA (1996) Recent advances in plant response to mechanical stress: theory and application. HortScience 31:31–35
Mohiuddin AKM, Chowdhury MKU, Abdullah ZC, Napis S (1997) Influence of silver nitrate (ethylene inhibitor) on cucumber in vitro shoot regeneration. Plant Cell Tiss Org Cult 51:75–78
Murashige T, Skoog F (1962) A revised medium for rapid growth and bioxcopy assays with tobacco tissue cultures. Physiol Plant 15:473–497
Nair OM, Chung IM (2014) Assessment of silver nanoparticle-induced physiological and molecular changes in Arabidopsis thaliana. Environ Sci Pollut Res 21:8858–8869. https://doi.org/10.1007/s11356-014-2822-y
Nakano Y, Asada K (1981) Hydrogen peroxide is scavenged by ascorbate specific peroxide in spinach chloroplast. Plant Cell Physiol 22:867–880
Purnhauser L, Medgyesy P, Czakó M, Dix PJ, Márton L (1987) Stimulation of shoot regeneration in Triticum aestivum and Nicotiana plumbaginifolia Viv. tissue cultures using the ethylene inhibitor AgNO3. Plant Cell Rep 6:1–4
Qian H, Peng X, Han X, Ren J, Sun L, Fu Z. (2013) Comparison of the toxicity of silver nanoparticles and silver ions on the growth of terrestrial plant model Arabidopsis thaliana. J Environ Sci 25:1947–1956. https://doi.org/10.1016/S1001-0742(12)60301-5
Qin Y, Li H-L, Guo Y-D (2007) High-frequency embryogenesis, regeneration of broccoli (Brassica oleracea var. italica) and analysis of genetic stability by RAPD. Sci Hortic 111:203–208
Rodriguez FI, Esch JJ, Hall AE, Binder BM, Schaller GE, Bleecker AB (1999) A copper cofactor for the ethylene receptor ETR1 from Arabidopsis. Science 283:996–998
Rui M, Ma C, Tang X, Yang J, Jiang F, Pan Y, Xiang Z, Hao Y, Rui Y, Cao W, Xing B (2017) Phytotoxicity of silver nanoparticles to peanut (Arachis hypogaea L.): physiological responses and food safety. ACS Sustain Chem Eng 5:6557–6567
Saha N, Gupta SD (2018) Promotion of shoot regeneration of Swertia chirata by biosynthesized silver nanoparticles and their involvement in ethylene interceptions and activation of antioxidant activity. Cell Tiss Org Cult 134:289–300
Salama HMH (2012) Effects of Ag nanoparticles in some crop plants, common bean (Phaseolus vulgaris L.) and corn (Zea mays L.). Int Res J Biotechnol 3:190–197
Sarmast M, Niazi A, Salehi H, Abolimoghadam A (2015) Silver nanoparticles affect ACS expression in Tecomella undulata in vitro culture. Plant Cell Tiss Org Cult 121:227–236
Sarmast M, Salehi H, Khosh-Khui M (2011) Nano silver treatment is effective in reducing bacterial contaminations of Araucaria excelsa R. Br. var. glauca explants. Acta Biol Hung 62:477–484
Sarmast MK, Salehi H (2016) Silver nanoparticles: an influential element in plant nanobiotechnology. Mol Biotechnol 58:441–449
Sharma P, Bhatt D, Zaidi MG, Saradhi PP, Khanna PK, Arora S (2012) Ag-nanoparticle-mediated enhancement in growth and antioxidant status of Brassica juncea. Appl Biochem Biotechnol 167:2225–2233
Solgi M, Kafi M, Taghavi TS, Naderi R (2009) Essential oils and silver nanoparticles (SNP) as novel agents to extend vase-life of gerbera (Gerbera jamesonii cv. ‘Dune’) flowers. Postharvest Biol Technol 53:155–158
Stampoulis D, Sinha SK, White JC (2009) Assay-dependent phytotoxicity of nanoparticles to plants. Environ Sci Technol 43:9473–9479
Sun J, Wang L, Li S, Yin L, Huang J, Chen C (2017) Toxicity of silver nanoparticles to Arabidopsis: inhibition of root gravitropism by interfering with auxin pathway. Environ Toxicol Chem 36:2773–2780
Syu Y, Hung JH, Chen JC, Chuang H (2014) Impacts of size and shape of silver nanoparticles on Arabidopsis plant growth and gene expression. Plant Physiol Biochem 83:57–64
Taiz L, Zeiger E, Møller I M, Murphy A (2015). Plant physiology and development. Sinauer Associates, Inc (p. 761)
Thuesombat P, Hannongbua S, Akasit S, Chadchawan S (2014) Effect of silver nanoparticles on rice (Oryza sativa L. cv. KDML 105) seed germination and seedling growth. Ecotoxicol Environ Saf 104:302–309
Tsukagoshi H (2012) Defective root growth triggered by oxidative stress is controlled through the expression of cell cycle-related genes. Plant Sci 197:30–39
Vannini C, Domingo G, Onelli E, Prinsi B, Marsoni M, Espen L, Bracale M (2013) Morphological and proteomic responses of Eruca sativa exposed to silver nanoparticles or silver nitrate. PLoS One 8:e68752
Wang C, Wang L, Wang Y, Liang Y, Zhang J (2012) Toxicity effects of four typical nanomaterials on the growth of Escherichia coli, Bacillus subtilis and Agrobacterium tumefaciens. Environ Earth Sci 65:1643–1649
Wang F, Cui X, Sun Y, Dong C-H (2013a) Ethylene signaling and regulation in plant growth and stress responses. Plant Cell Rep 32:1099–1109
Wang J, Koo Y, Alexander A, Yang Y, Westerhof S, Zhang Q, Schnoor JL, Colvin VL, Braam J, Alvarez PJ (2013b) Phytostimulation of poplars and Arabidopsis exposed to silver nanoparticles and Ag+ at sublethal concentrations. Environ Sci Thnol 47:5442–5449
Wang KL, Li H, Ecker JR (2002) Ethylene biosynthesis and signaling networks. Plant Cell 14(suppl):S131–S151
Yang SF (1980) Regulation of ethylene biosynthesis. HortScience 15:238e243
Yang J, Jiang F, Ma C, Rui Y, Rui M, Adeel M, Cao W, Xing B (2018) Alteration of crop yield and quality of wheat upon exposure to silver nanoparticles in a life cycle study. J Agric Food Chem 66:2589–2597. https://doi.org/10.1021/acs.jafc.7b04904
Yin L, Colman BP, McGill BM, Wright JP, Bernhardt ES (2012) Effects of Ag nanoparticle exposure on germination and early growth of eleven wetland plants. PLoS One 7:e47674. https://doi.org/10.1371/journal.pone.0047674
Zhang P, Phansiri S, Puonti-Kaerlas J (2001) Improvement of cassava shoot organogenesis by the use of silver nitrate in vitro. Tiss Org Cult 67:47–54
Ziv M (1991) Quality of micropropagated plants—vitrification. In Vitro Cell Dev Biol - Plant 27:64–69
Acknowledgements
This work was supported in part by Gorgan University of Agricultural Sciences and Natural Resources (GUASNR) and Shiraz University. My special thanks to Cade Guthrie for reading and revising the manuscript.
Author information
Authors and Affiliations
Contributions
MKS: writing—original draft; visualization; project administration; data curation; resources; software; HS: conceptualization, resources.
Corresponding author
Ethics declarations
Conflict of interest
The authors declare no competing interests.
Additional information
Editor: Zhezhi Wang
Rights and permissions
About this article
Cite this article
Sarmast, M.K., Salehi, H. Sub-lethal concentrations of silver nanoparticles mediate a phytostimulatory response in tobacco via the suppression of ethylene biosynthetic genes and the ethylene signaling pathway. In Vitro Cell.Dev.Biol.-Plant 58, 1–14 (2022). https://doi.org/10.1007/s11627-021-10193-1
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11627-021-10193-1