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Buckwheat (Fagopyrum esculentum Moench) is an important functional food and rich source of vitamins, essential amino acids and phenolics, responsible for many of the health benefits and antioxidant properties. This pseudocereal contains quercetin-3-rutinoside or rutin as a major phenol in seeds, approx. 90.4% of total flavonols content. Rutin is an antioxidant that has many pharmacologically useful properties, such as anti-inflammatory, anticarcinogenic, antithrombotic, cytoprotective and vasoprotective effects. The aim of this study was to investigate content of rutin in seeds of cultivars from Western, Central Europe and Balkans: Serbia (´Novosadska´), Slovenia (´Darja´, ´Prekmurska´ and ´Cebelica´), Bosnia and Herzegovina (´Bosna 1´ and ´Bosna 2´), Montenegro (´Godijevo´ and ´Lokve´), Austria (´Bamby´), Czech Republic (´Ceska´), France (´La Harpe´), Slovakia (´Spacinska 1´) grown in the Balkan area and to compare them with indigenous Balkan buckwheat cultivars. Rutin content was determined using HPLC-DAD analysis, on a Thermo Finnigan Surveyor HPLC system with a diode array detector at 350 nm. ´Bosna 1´ (114.6 mg 100 g-1 dry weight) and ´Bosna 2´ (151.4 mg 100 g-1 dry weight) were highlighted with the greatest rutin content, 13.6-34.7 and 18.0-45.9 times higher than in other cultivars, respectively. Beside these two cultivars, a scale made according to rutin content in buckwheat seeds organise investigated cultivars in the following order: ´Novosadska´ > ´La Harpe´ >´ Godijevo´ >´ Darja´ > ´Cebelica´ > ´Bamby´ > ´Ceska´ > ´Spacinska 1´ > ´Prekmurska´ > ´Lokve´. These results suggest that indigenous buckwheat cultivars contain important dietary antioxidants and could be of great interest for buckwheat breeders and an important source of functional food due to significant differences in their contents among cultivars.

Accumulation of phenolic polymers reinforce plant cell walls, limiting fungal penetration. Some of these compounds, such as isochlorogenic acid, are particularly active in limiting fungal extension. Two main features of phenolic compounds are that they are produced in greater quantities by resistant plant genotypes, and that they have the ability to limit plant pathogens growth. Thus, they could be considered as potential markers of resistance to Monilinia laxa in sweet cherrie breeding programs. We investigated the content of the total phenols (TP), total tannins (TT) and anthocyanins (A) in the fruits of ten sweet cherrie cultivars, before and after the infection with M. laxa, under the field conditions. In addition to this, we determined the total antioxidant capacity of the fruit extracts using the DPPH-free radical scavenging assay and FRAP method. The correlations between phenolic classes and antioxidant activity have been calculated, as well. Results showed that the TP content ranged from 3.71 to 7.52 mg gallic acid equivalent (GAE) g-1 dry weight depending on the genotype and the infection. TT content was lower and it ranged from 0.52 to 2.64 mg GAE g-1 dry weight. Anthocyanins content ranged from 0.29 to 2.71 mg cyanidin-3-glucoside g-1 dry weight. DPPH values ranged from 38.47 to 63.50 % of neutralised radicals, while FRAPvalues were 14.73-33.69 mg trolox g-1 fresh weight. No positive correlation was found for antioxidant tests and phenolic compounds investigated. Still, TP and TT were higher in infected fruits of five specimen (Junska rana, Summit, Mershant, Priusodebnaja and Burlat), and A levels were higher in the same cultivars except for the cv. Summit. These cultivars accumulate defensive compounds under the pathogen induced stress and may be considered as more tolerant genotypes with more desired traits for production, selection and breeding programmes.

Oxidative metabolism of normal cells and different stress situations generate highly reactive oxygen species (ROS). The ROS have been implicated in a number of physiological disorders in plants. Such factors as certain mechanical injuries are known to induce ROS formation in most aerobic organisms. Antioxidant defence systems have co-evolved with aerobic metabolism to counteract oxidative damage from ROS. This includes antioxidant enzymes such as superoxide-dismutase (SOD; EC 1.15.1.1). SOD is of the greatest importance since it catalyzes the dismutation of the superoxide radical (O2.-) to O2 and H2O. Thus, the aim of this study was to measure the intensity of SOD in the leaves of six cherry rootstock selections in order to investigate the effect of exogenously applied auxins on the mechanical injury induced oxidative stress during the process of rooting of softwood cuttings. The experiment was carried out in the plastic house under a fogging system with 95-99% average relative humidity. The 15-20 cm long terminal cuttings were treated with the mix of auxins (IBA, 0.5% and α-NAA, 0.8%) powder prior to insertion into the white sphagnum and perlite substrate mixture. Leaves of six promising rootstock selections of Prunus cerasus L., P. mahaleb L. and P. fruticosa Pall., and one standard rootstock PHL-A were sampled on the 1st, 3rd and 7th day after inserting softwood cuttings into the rooting substrate. The SOD activity was measured by monitoring the inhibition of nitroblue-tetrazolium (NBT) reduction at 560 nm. Results showed that generation of ROS occurred in all investigated genotypes, but they greatly differed in susceptibility towards oxidative stress induces by mechanical injury. Application of auxins on standard vegetative rootstock PHL-A, as well as P. mahaleb selection M6 showed positive effect on lowering SOD activity after the 3rd and 7th collecting day compared to control. On the other hand, selections of P. cerasus OV22 and P. fruticosa SV2 expressed high SOD activity during all collecting days which was from 3.6-54.9% higher compared to control. Enhanced SOD activity in leaves of softwood cuttings indicates induction of the enzymatic antioxidant system in both auxin treated and untreated cutting. According to these results SOD activity could be used as one of the biochemical parameters in further rootstock selection for sweet and sour cherries.

The purpose of this work was to define the reaction of soybean and maize plants to inoculation with plant growth-promoting rhizobacteria (PGPR) [isolates of Azotobacter (AB), Streptomyces (S) and mixture of these (MIX)], by investigating lipid peroxidation intensity. Lipid peroxidation (LP) represents a valuable biomarker of cell degradation and oxidative stress secondary effects. It is analyzed as a response of plants exposed to various (a)biotic factors and in this work it is expressed as nmol malondialdehyde (MDA) equivalents in fresh leaves and roots of investigated plants. Seeds of soybean (cultivar Bečejka) and maize (hybrid NS 640) were inoculated with aqueous inoculums of tested PGPRs and grown under field conditions, without fertilization. Plants were harvested for biochemical analyses at three specific stages of development: 21-day-old seedlings, full bloom, seed beginning stage and, at the end of the experiments, yield was recorded. Inoculated plants had similar values of LP intensity as plants from control (35.1-98.9 nmol MDA g-1 fresh weight). There were no significant differences in LP intensity between control and treatments within the sampling stage, however the amount of MDA accumulated during the vegetation period (up to 60%), possibly because of the developmental processes in soybean and maize. As for seed yield (t ha-1), both investigated species had 5-7% higher yield when inoculated with MIX inoculum, which highlighted the coupled inoculation as possible potent biofertilizer in soybean and maize organic production.

The purpose of this research was to compare how soybean seedlings (Glycine max L., cultivar Bečejka) cope with different nutrition acquisition strategies of hemibiotrophic fungi: Rhizoctonia solani Kühn and Sclerotinia sclerotiorum (Lib.) de Bary. Severe changes at morphological and histological level after inoculation with both fungi were accompanied by significant changes in nitrogen assimilation enzymes activities in leaves and roots of 21-day-old soybean plants. Infected seedlings had decreased nitrate reductase (NR) (2-fold the amount of control, on average) and glutamate synthase (GS) activity (40-60%), except in leaves infected with S. sclerotiorum. Glutamate dehydrogenase (GDH) activity increased 46-75% after the pathogen infection, being highest during R. solani infection. High GDH values in infected organs (0.26-0.47 μmol NADH mg-1 protein) point to enhanced nitrogen remobilization process from infected tissue, possibly to restrict available nutrients to pathogens, among other things beneficial to plant. Differences in GS and GDH activities in the same organs depending on pathogen infection showed that plants cope differently with these fungi at this stage of development, or that time of switching from bio- to necrotrophic lifestyle differs between investigated pathogens. Due to adaptable lifestyle of hemibiotrophic fungi, mechanistic details that allow pathogen to control host metabolic pathways are unknown, and for this reason the understanding of plant nutrient acquisition could be of great importance in the development of novel disease control strategies.

Accompanied by oxidative stress as a signal to activate defense mechanisms, various abiotic factors induce peroxidation of membrane lipids. The aim of this research was to analyse changes in lipid peroxidation (LP) intensity and antioxidant capacity of selected sugar beet genotypes during micropropagation under the conditions of water deficit. Performed research represents a part of a more comprehensive study, the purpose of which is understanding the difference in acclimation to drought as the major abiotic factor limiting sugar beet production in Serbia. The best solution for overcoming this obstacle in successful sugar beet growing is breeding for drought tolerance. Tested sugar beet genotypes were grown and multiplied in vitro on standard nutrient medium. Axillary shoots were placed on the micropropagation media with 3% and 5% PEG for 28 days, which caused physiological drought stress. All genotypes could be divided into three groups according to the level of LP, however only two of eight genotypes had significantly higher LP intensity during drought conditions when compared to their controls (10.1-29.1%), as well as significantly reduced antioxidant activity (22.2-59.9%). A slight decrease in LP intensity and enhanced antioxidant capacity (up to 92.9%) in comparison to control were recorded in treatments of the rest of investigated genotypes. As for correlation between tested biochemical parameters and growth conditions, all genotypes differed in their response to PEG concentration. Obtained results showed that LP intensity and antioxidant capacity could be used as biochemical parameters in assessing drought tolerance of individual genotypes in further selection of sugar beet.

Compounds which add to bioactivity of elderberry (Sambucus nigra L.) are mostly phenolic compounds. One wild edible and two cultivated genotypes (’Haschberg’ and ’Ljubostinja’ selections) have been chosen. Leaves and fruits were collected in four stages (April-September). Total phenolics (TP) content was determined from MeOH extracts by Folin-Ciocalteau method while determination of individual compounds was performed using HPLC-DAD-ESI-MSn analysis with a DAD at 280, 350 and 530 nm. TP content in leaves varied through developmental stages, being higher in II and III stage. Leaves and fruits (both unripe and ripe) of ’Ljubostinja’ plants had higher content of TP compared to wild ripe fruits (1.5-fold). Leaves had caffeic acid derivatives (0.3-0.7% in wild, 0.2-0.3% in ’Haschberg’ and 0.4-0.6% in ’Ljubostinja’ in dry weigh) and caffeoylquinic acid derivatives, while fruits had more caffeoylquinic acid derivatives, particularly unripe fruits. The major phenolic acid present in leaves, especially during the II stage of development, was chlorogenic acid (approx. 4% dw) and the same was recorded in fruits (0.03% dw in unripe fruits of wild plants). Content of phenolic acids decreased during ripening of elderberry fruits and the similar was detected in the leaves.

The objective of this study was to determine the content of phenolic compounds (total phenolics, total tannins and total flavonoids) and antioxidant capacity by six different assays in industrial hemp (‘Helena’ variety) extracted by four different extraction solvents: 70% methanol, 70% ethanol, 70% acetone and water. Out of the four solvent mixtures evaluated in the current study for the extraction of phenolic compounds, the use of 70% acetone yielded to the highest total contents of phenolics and exhibited the highest antioxidant activity in all performed assays.

The most common herbicide combination for weed prevention in soybean is Pulsar 40 and Harmony 75WG, but when applied during hot days these herbicides may induce oxidative stress in plants. Delfan Plus® is a biostimulator with high amino acid content which can be used in combination with herbicides. Manufacturer advertises it as a supplement for faster protein synthesis and thus, overcoming stress conditions caused by high and low temperatures, drought, herbicides etc. In order to investigate the ability of Delfan Plus® to mitigate the effect of herbicides on soybean plants (and its weed species Datura stramonium L.), we analyzed the accumulation of polyphenolic compounds (total polyphenols, tannins, flavonoids and proanthocyanidins), as well as phytotoxicity and grain yield. In addition, we determined the antioxidant capacity of plant extracts in DPPH and NBT-tests. Soybean cultivar Sava was treated with Pulsar 40 + Harmony 75WG (1 L ha-1 + 8 g ha-1 and 2 L ha-1 + 16 g ha-1, respectively), with or without Delfan Plus® (1 L ha-1 and 2 L ha-1, respectively). Biochemical parameters analyzed showed that Delfan plus® did not decrease the level of stress in plants. Most parameters increased their values 7 days after the treatment, compared to day 1, which was expected. Specimens of D. stramonium were especially stressed after herbicide treatment. Although soybean yield was somewhat higher after the treatment with normal dose of herbicides and Delfan plus® (3.28 t ha-1), there were no statistical differences between the treatments. Hence, the question of the application of this biostimulator in agronomic practice may be raised.

Changes in enzymatic and non-enzymatic antioxidant systems in leaves and roots of soybean and maize seedlings were studied after inoculation with Rhizoctonia solani Kühn, AG 2-2 IIIB. After the infection with R. solani, increase in superoxide anion (O2 .- ) scavenging activity was recorded only in leaves and roots of soybean plants. Hydroxyl radical (.OH), the production of which was remarkably increased in infected soybean seedlings, were invariably produced in infected maize seedlings in comparison to control. Furthermore, superoxide-dismutase activity increased only in infected maize roots, which could point to enhanced O2 .-dismutation. Nevertheless, lipid peroxidation intensity was notably recorded only in soybean plants, which could lead to presumption that .OH was successfully neutralized in maize seedlings and that membrane lipids were prevented from peroxidation with .OH, potentially the most responsible for these processes. Peroxidase were significantly active in infected leaves compared to control in both species, especially in soybean. Naturally, ROS accumulation induced significantly enhanced phenylalanin ammonialyase (PAL) activity, which escalated phenolic compounds synthesis in maize seedlings. Ability to accumulate phenolics, under the condition of pathogen attack, correlated with the results for the DPPH-assay that determines these maize plants in active group1.

Elderberry (Sambucus nigra L.) is a common plant used for its medicinal and nutritional properties, as for the beverages, jams, liqueurs, flavourings etc. Plant material examined were leaves and fruits of wild edible, and cultivated elderberry plants (’Haschberg’ and ’Ljubostinja’ selections). Determination of organic acids and sugars was performed using high-performance liquid chromatography. Organic acids found in the tested fruit samples were citric, tartaric, malic, quinic, shikimic and fumaric acids, out of which quinic acid content was the highest in unripe, while citric acid content was the highest in ripe fruits. Wild plants had higher contents of organic acids in unripe fruits (16.7 g 100 g-1dw) than cultivated (’Haschberg’ 6.6, and ’Ljubostinja’ 6.3 g 100 g-1dw). ’Ljubostinja’ selection had significantly higher organic acids content (10.2 g 100 g-1dw) in ripe fruits compared to wild specimen and ’Haschberg’ plants which had similar organic acids content (7.0 and 7.4 g 100 g-1dw). The major organic acid in ripe elderberry fruits was citric acid. When it comes to sugars content the presence of sucrose, glucose, fructose and sorbitol was established. Wild specimen had significantly higher sugars content (2.2 in unripe, and 8.4 g 100 g-1dw in ripe fruits).

U ovom radu su ispitani hemijski sastav i biološka aktivnost vrsta Brassica oleracea i Brassica rapa poreklom iz organskog i konvencionalnog sistema proizvodnje. Ispitivanja hemijskog sastava su obuhvatila određivanje volatilnih komponenata primenom headspace GC-MS tehnike, kvalitativnu analizu sokova ispitivanih vrsta pomoću LC-DAD-MS/MS tehnike, kvantifikaciju odabranih fenolnih jedinjenjapomoću LC-MS/MS tehnike i spektrofotometrijsko određivanje sadržaja ukupnih glukozinolata, fenola i flavonoida i sadržaja ukupnih monomernih antocijana. Biološka aktivnost povrća je ispitana određivanjem antioksidantnog potencijal, antimikrobne i antitumorske aktivnosti sokova. Dobijeni rezultati pokazuju da su glavne volatilne komponente ispitivanih vrsta degradacioni proizvodi masnih kiselina i organosumpornih jedinjenja od kojih neke od identifikovanih komponenata predstavljaju ključne mirisne komponente. Na osnovu njihove distribucije nije bilo moguće utvrditi uticaj sistema proizvodnje na miris i ukus ispitivanih vrsta. Pomoću LC-DAD-MS/MS i LC-MS/MS tehnike je utvrđeno prisustvo primarnih metabolita, slobodnih hidroksibenzoevih i hidroksicimetnih kiselina, derivate hinske kiselinesa hidroksicimetnim kiselinama, glikozida flavonola, biflavonoida, i kumarina u sokovima spitivanih vrsta. Pored toga u svim sokovima subili prisutni kondenzacioni proizvodi degradacionih proizvoda indolnih glukozinolata sa askorbinskom kiselinom- askorbigen i metoksiaskorbigen. U sokovima crvenog kupusa su bili prisutni antocijani. Najveći sadržaj ukupnih glukozinolata je određen u brokoliju, dok je crveni kupus sadržao najveći sadržaj ukupnih fenola ukupnih flavonoida kao i hinske kiseline. Crveni kupus je bio varijetet koji je ispoljio najviši antioksidantni kapacitet u svim primenjenim testovima, brokoli i karfiol su ispoljili najjaču antimikrobnu aktivnost, dok je kelj bio varijetet sa najjačim antitumorskim delovanjem. Na osnovu analize hemijskog sastava i biološke aktivnosti vrsta B. oleracea i B. rapa može se zaključiti da u zavisnosti od primenjenog tipaproizvodnje mogu biti poboljšane neke od karakteristika ispitivanih vrsta i da je uticaj sistema proizvodnje značajan za pojedine varijetete, a nikako za celu vrstu. U konačnom obliku može se zaključiti da bi potencijalna kombinacija sokova crvenog kupusa, brokolija, karfiola i kelja mogla ostvariti značajno hemopreventivno i hemoterapeutsko delovanje, ispoljavajući istovremeno antioksidantnu, antimikrobnu i antitumorsku aktivnost., Chemical composition and biological activity of Brassica oleracea and B. rapa species were investigated in the present work. Investigation of chemical composition encompassed determination of volatile compounds by headspace GC-MS technique, qualitative analysis of juices of investigated vegetables by LC-DAD-MS/MS technique, quantification of selected phenolic compounds by LC-MS/MS technique and spectrophotometric determination of total content of glucosinolates, phenolic compounds and flavonoids and total content of monomeric anthocyanes. Biological activity of vegetables was investigated by determination of antioxidant capacity, antimicrobial and antitumorigenic effect of juices. Obtained results showed that main volatile compounds were degradation products of fatty acids and organo-sulphur compounds among which some of the identified components were the key aroma compounds. Based on their distribution it was not possible to evaluate influence of cropping system on aroma and taste of investigated species. By LC-DAD-MS/MS and LC-MS/MS techniques, it was determined the presence of primary metabolites, freehydroxybenzoic and hydroxycinnamic acids, derivatives of quinic acid and hidroxicinnamic acids, flavonol glucosides, biflavnoids and a cumarin in juices of the investigated species. Furthermore, condensation products of degradation products of indole glucosinolates with ascorbic acid- ascorbigen and metoxiascorbigen were present in all juices. Anthocyanes were present in juices of red cabbage. The highest total content of glucosinolates was determined in broccoli, while red cabbage had the highest total phenolic content, total flavonoid content, as well as content of qunic acid. Red cabbage was a variety that showed the highest antioxidant capacity measured by different assays. Broccoli and cauliflower expressed the highest antimicrobial potential, while Savoy cabbage was a variety with the highest antitumor effect. Investigation of chemical composition and biological activity showed that applied cropping conditions may be useful for improving some of the characteristics of investigated species and significance of cropping system only for particular varieties, but not for the whole species in general. As the conclusion, potential combination of juices of red cabbage, broccoli, cauliflower and Savoy cabbage could be potent chemopreventive and chemotherapeutic agent, expressing simultaneously antioxidant, antimicrobial and antitumor activity.

Predmet ovog istaživanja bio je ispitivanjeuticaja jona tri teška metala (Ni2+, Cu2+i Cd2+)u dve toksične koncentracije u zemljištu nafiziološke i biohemijske karakteristikeodabranih klonova topola, M1, B229 i Pe 19/66.Ispitan je i potencijal odabranih klonova topolada vrše fitoekstrakciju-akumulaciju teškihmetala iz zemljišta u svoje nadzemne delove štodovodi do dugoročnog uklanjanja ovihperzistentnih polutanata iz životne sredine.Takođe, ispitan je uticaj teških metala naantioksidantni potencijal, sposobnostneutalizacije slobodnih radikala, aktivnostiantioksidantih enzima kao i na sadržajslobodnih i konjugovanih poliamina (Put, Spm,Spd), određenih HPLC analizom, i sadržajbiljnih hormona poput indol-3-sirćetne kiselinei abscisinske kiseline, određenih GC/MSanalizom, u listovima i korenovima klonova topola.&nbsp, The aim of this study was to estimate and compare phytoextraction capacities of threepoplar clones (M1, B229 and Pe 19/66) in soil. Furthermore, the goal was to assess different biological responses among the poplar clones during exposure to different concentration of three heavy metal ions (Ni2+, Cu2+ i Cd2+). In order to track changes in poplars’mineral, physiological, biochemical and antioxidant status during the abiotic stress, quantification of physiological properties, free and conjugated polyamines, total phenolics as well as quantification of phytohormones (indol-3-acetic and abscisic acid) was done. Furthermore, assessment of antioxidant potential by tracking radical scavenger capacities (RSC) against DPPH, ABTS, OH and NO radicals and by measuring enzymes activities (SOD, GSH-Px, GPx, GR) in vitro was performed in root and leaves of poplar clones.