Authors:B. Szabó, E. Tyihák, Gy. Szabó, and L. Botz
Papaver somniferum produces secondary metabolites, which have important roles in their self-defence processes, in plant biochemistry and in allelochemistry. We can see that different stress effects change the quantity of alkaloids. The object of the experiments is, in what manner changes the content of alkaloids of poppy in case of irregular stress effects. Papaver somniferum (cv. 'Kék Duna', Budakalász) plants were grown for 2 months from seeds in quartz-sand (in natural light, temperature: 24-28 °C, in Knop's nutritive solution). In this paper we studied the alkaloid of poppy treated with two kind of stress factors: mycotoxin and drought, respectively. Both the quantity and the spectrum of alkaloids were measured after different separation procedures. Thin layer chromatography (TLC and HPTLC) and high performance liquid chromatography (HPLC) were applied. Content of the level of formaldehyde (HCHO) also increases in plants with different stress effects. Our presupposition is that the formation of methyl groups of poppy alkaloids takes place through HCHO. It gave us an opportunity to examine changing of formaldehyde (HCHO) level in biotic and abiotic stress situation. Formaldehyde in dimedone adduct form can be detected in injured tissues of Papaver somniferum. As a consequence, the stress effects can be detected in poppy plants by two kinds of method. At first we measured content of alkaloids. Drought stress produced a higher level of the alkaloids, but the mycotoxin stress did not show significant results.
Phenoloids with allelopathic effect (juglone, ctaechin, tannin, gallic acid t-cinnamic acid, caffeic acid, coumarin, thymol, salicin in 1mM concentration) cannot be detected after the absorption from the acceptor plant (bean) by the applied selective analytical method (TLC densitometry). Their localisation can be determined by histochemical reagens (ferrichloride, potassium bichromate, sodium hydroxide). In the foliage leaves and excised bean plants they are present mainly in the parenchymatuos elements of the vascular tissue already on the 3rd day, at the beginning of wilting. Some substances (tropanes) out of the studied allelopathic alkaloids (atropine, scopolamine, belladonnin, tropine and caffeine) can be detected only in small amounts (7-8%) or only in traces in the leaf. Others (e.g. caffeine) accumulate in substantial amount (almost 200%) in their original form. Alkaloids,as well as phenoloids, can be detected in lesf tissue by histochemical methods (Dragendorff and Meyer reagents).
Authors:Beáta Szabó, Á. Lakatos, T. Kőszegi, and L. Botz
We aimed to understand the effects of water stress on the alkaloid production in various developmental stages of poppy plants and the effect of stress on the alkaloids content in the capsules. Three stages of the life cycle of
L. were selected in our studies: Rosette, Flowering and Lancing developmental stages. Four types of water conditions were examined: Control, Withdrawal of Water, 50% Water Supply and Inundation.The morphological monitoring, results of Relative Water Content and proline content were used as indicators of stress. The result of the measurements in poppy leaves show that the secondary metabolites dramatically respond to these stress conditions. The constant water supply was beneficial for the accumulation of alkaloids in the capsules.
Authors:Gy. Horváth, L. Botz, B. Kocsis, É. Lemberkovics, and L. Gy. Szabó
Certain classes of bioactive compounds can be separated using planar chromatography. Some biological effects (e.g. antibacterial) of these compounds can be investigated directly by examining the growth of a test organism on a specially treated sorbent of thin layer chromatography (TLC). A special method of detection, direct bioautography, is suitable for studying the antimicrobial activity of plant extracts of natural origin by using TLC. Zones of inhibition are visualised by use of a dehydrogenase-activity-detecting, tetrazol-type reagent. Zones of inhibition appeared as pale spots separating well from the dark background. The antibacterial effect of the main essential oil components of some Thymus taxa, as well as that of two antibiotics (streptomycin sulphate and gentamycin) known and applied in practice was investigated against plant pathogenic bacteria. Results showed that thyme essential oil and its components inhibited the growth of test bacteria, but not so considerably as the antibiotics applied. Compositions of the essential oils were analysed by gas chromatography (GC). It could be verified that among the essential oil components, thymol and carvacrol had the strongest inhibitory effect.