Morphological, Physiological and Biochemical Respon ses of Crops ( Zea mays L., Phaseolus vulgaris L.), Medicinal Plants ( Hyssopus officinalis L., Nigella sativa L.), and Weeds ( Amaranthus retroflexus L., Taraxacum officinale F. H. Wigg) Exposed to SiO 2 Nanoparticles

Abstract

In this research, two field crops ( Zea mays L. and Phaseolus vulgaris L.), two medicinal plants ( Hyssopus officinalis L. and Nigella sativa L.) and two weeds ( Amaranthus retroflexus L. and Taraxacum officinale F. H. Wigg) were separately treated with three concentrations of SiO 2 nanoparticles (400, 2,000, and 4,000 mg L -1 ). The effects of these treatments on morphological and biochemical charact eristics of the plants were assessed, including germination, root and shoot length, root and shoot fresh weight, root and shoot dry weight, photosynthetic pigments, total carbohyd rates, total protein, total amino acid, and proline content. In the crops and medicinal pla nts, 400 mg L -1 SiO 2 NPs significantly increased seed germination, root and shoot lengths, fresh weights (except for H. officinalis ) and dry weights, photosynthetic pigments, total p rotein, and total amino acid (except for H. officinalis ). In weeds, as SiO 2 NP concentration increased from 400 to 4,000 mg L -1 , germination, root and shoot lengths, fresh and dr y weights, and photosynthetic pigments as well as total protein decreased. Total carbohydrates in all plants decreased significantly, except for A. retroflexus at 400 mg L -1 SiO 2 NPs. In all plant species, with increasing SiO 2 NP concentration, proline content increased signifi cantly. According to these results, a lower concentration of SiO 2 NPs can have beneficial effects on morphological, physiological, and biochemical chara cteristics of plants. Keywords: Germination, Photosynthetic pigments, Total amino a cid, Total carbohydrates, Total protein