The effect of a colloidal solution of Cu,Zn-nanoparticles on pro-oxidative/antioxidative balance and content of photosynthetic pigments and leaf area of winter wheat plants of steppe (Acveduc) and forest-steppe (Stolichna) ecotypes was investigated in drought conditions. It has been shown that Cu,Zn-nanoparticles decreased the negative effect of drought action upon plants of steppe ecotype Acveduc. In particular, increased activity of antioxidative enzymes reduced the level of accumulation of thiobarbituric acid reactive substances (TBARS) and stabilized the content of photosynthetic pigments and increased relative water content in leaves. Colloidal solution of Cu,Zn-nanoparticles had less significant influence on these indexes in seedlings of the Stolichna variety under drought.

The use of colloidal solutions of metals as micronutrients enhances plant resistance to unfavorable environmental conditions and ensures high yields of food crops due to the active penetration of nanoelements into the plant cells. Microbiological examination of rhizosphere soil have revealed that combined use of colloidal solution of nanoparticles of molybdenum (CSNM, 8 mg/l), and microbial preparation for pre-sowing inoculation of chickpea seeds stimulates the development of ‘agronomically valuable’ microflora. It was shown that combined seed treatment with colloidal solution of Mo nanoparticles with microbial preparation have stimulated nodule formation per plant by four times compared to controls. Single treatment with CSNM increased the number of nodules by two times, while the treatment of microbial preparation have not significantly affected the number of nodules per plant. PACS Colloids, 82.70.Dd; Ecology, 87.23.-n

The paper presents research data of lipid peroxidation and lectin activity in wheat seedlings at seed treatment with solution of metal nanoparticles (Zn, Ag, Fe, Mn, Cu) and sole solution of copper nanoparticles under the high pathogen infection background of Pseudocercosporella herpotrichoides (Fron) Deighton (synonym: Oculimacula yallundae (Wallwork & Sponer) Crous & W. Gams). It was shown that investigated nonionic colloidal solutions of biogenic metals have the antioxidant effect through the inhibition of the synthesis of lipid peroxidation products. The increase of lectin activity levels during the early plants ontogenesis stages was observed in wheat seedlings infected with pathogen pre-treated with the mixture of metal nanoparticles.

The paper covers the research of copper and zinc nanoparticle effect on the content of ascorbic acid, and quantitative and qualitative composition of amino acids and acylcarnitines in Pistia stratiotes L. plants. Plant exposition to copper nanoparticles led to the decrease in (1) the amount of ascorbic acid, (2) the total content of amino acids (by 25 %), and (3) the amount of all studied amino acids except for the glycine amino acid. At this, the amount of 5-oxoproline, arginine, leucine, ornithine, phenylalanine, proline, serine, and tyrosine was two times lower than in control plants. The reduction of the contents of 8 out of 12 investigated acylcarnitines (namely C0, C2, C3, C5, C6, C8, C16, C18:1) was observed in plants under the influence of copper nanoparticles. The result of plants incubation with zinc nanoparticles was the decrease in (1) the amount of ascorbic acid, (2) the total content of amino acids (by 15 %), (3) the content of leucine, methionine, phenylalanine, proline, and tyrosine (more than twice), and (4) the content of 10 acylcarnitines (C0, C2, C3, C4, C5, C10, C16, C18, C18:1, C18:2). The observed reduction in amino acid contents may negatively affect plants adaptive reactions associated with de novo synthesis of stress proteins. At the same time, the decrease in the content of acylcarnitines, responsible for fatty acid transportation, may lead to the changes in the activity and direction of lipid metabolism in plants and reduce plant’s ability to use free fatty acids as the oxidation substrate for cell reparation.

The affordable and scalable synthesis of noble metal nanoparticles that are biocompatible without additional functionalization steps has been a growing field of research, stimulated by numerous prospective applications of these NPs. In the case of phytosynthesized or biogenic noble metal NPs, the mechanism of NP stabilization by biomolecules contained in each particular plant extract or living organism determines the possible applications of these NPs. In this work, we investigated Ag NPs synthesized in water with plant extracts of common toothwort (Lathraea squamaria) and two species of pepper (Capsicum annuum and Capsicum chinense). From FTIR and XPS, we drew conclusions about the composition of the functional groups and molecules that stabilize NPs in each extract, such as polysaccharide compounds (pectins, cellulose, glycosides and phenolic acids). Distinct characteristic IR features of amide I and amide II proteins were observed, which are common in plant extracts, while features of amide III were not distinctly observed in our extracts. A Raman spectroscopy study revealed weak own-SERS activity of the biomolecules of the extract and high efficiency of the NPs in the enhancement of “external” analytes, such as dyes and antibodies. This is the first report of the efficient SERS application of phytosynthesized Ag NPs.