The effect of methyl jasmonate vapors on content of phenolic compounds in seedlings of common buckwheat (Fagopyrum esculentum Moench)

The effect of methyl jasmonate (MJ) vapors on content of phenolic compounds: free phenolic acids, total quercetin, and total phenolics in etiolated buckwheat seedlings were studied. The data presented show that low concentration of MJ (10-8 M) had no influence on trans-cinnamic acid (CA), but stimulated the accumulation of chlorogenic acid in hypocotyls and cotyledons of buckwheat seedlings. A moderate dose of MJ (10-6 M) did not change the level of chlorogenic acid in the hypocotyls and cotyledons, but CA synthesis was promoted in cotyledons, whereas in hypocotyls no significant effect was found. Highest concentration of MJ (10-4 M) caused small decline of CA in hypocotyls, but large stimulation of the acid production in cotyledons was noted. MJ had stimulatory effect on caffeic acid forming, but inhibited synthesis of vanillic acid in hypocotyls and cotyledons. Lowest concentration of MJ (10-8 M) elicited accumulation of quercetin glycosides in both studied tissues of buckwheat seedlings, however at higher doses (10-8 and 10-4 M) did not affect the flavonol level. The obtained results suggest that nonequivalent influence of methyl jasmonate on the phenolics composition can be a result of various mechanisms of MJ uptake, transforming and/or its translocation in buckwheat hypocotyls and cotyledons. Decline of anthocyanins level in buckwheat hypocotyls caused by MJ cannot be explained by enhanced accumulation of quercetin glycosides or free phenolic acids, but probably by synthesis of other unknown phenolic compounds

Methyl Jasmonate Induces Gummosis in Plants

Gum in plants is induced by environmental stress factors such as pathogens infection, insect attack, mechanical and chemical injuries, water stress and others. All these factors are considered to act via ethylene produced in plant tissues. Recently we have also shown that jasmonates, a new group of plant hormones, induced gummosis in tulip, peach, apricot, plum and cherry. This review paper describes physiological roles of jasmonates in gum induction and/or production in these plants and chemical compositions of gums. A possible mode of action of jasmonates in the process of gummosis will also be discussed in point of the interaction with ethylene

UV-B radiation increases anthocyanin levels in cotyledons and inhibits the growth of common buckwheat seedlings

The impact of short-term UV-B treatment on the content of individual flavonoids and photosynthetic pigments in cotyledons and the growth of common buckwheat (Fagopyrum esculentum Moench) seedlings was investigated. Seeds of four common buckwheat cultivars were germinated in darkness over a period of 4 days and acclimatized for 2 days under a 16/8 h light/dark photoperiod at 24/18 °C day/night, and exposure to 100–120 μmol ∙ m−2 ∙ s−1 of photosynthetically active radiation (PAR). Seedlings were divided into three batches, including two batches subjected to different doses of UV-B (5 W ∙ m−2 and 10 W ∙ m−2, one hour per day) for 5 days, and a control group exposed to PAR only. Exposure to UV-B increased anthocyanin levels in the cotyledons of all examined cultivars, it inhibited hypocotyl elongation, but did not affect the content of photosynthetic pigments. Flavone concentrations increased in cv. Red Corolla and Kora, remained constant in cv. Panda and decreased in cv. Hruszowska. Exposure to UV-B decreased rutin levels in cv. Hruszowska, but not in the remaining cultivars. Cultivars Hruszowska, Panda and Kora appeared to be less resistant to UV-B than Red Corolla. Higher resistance to UV-B radiation in Red Corolla can probably be attributed to its higher content of anthocyanins and rutin in comparison with the remaining cultivars

Wpływ przechowywania na zawartość kwercetyny w suszonej i mrożonej szalotce [Effect of storage on quercetin content in frozen and dried shallot]

The studies on effects of freezing and drying on quercetin content in shallot, as well as storage time of obtained products, were carried out. Two landraces, marked PV-S and PV201, were taken for the studies. The process of drying was carried out using a semi-technological drier operated by forced airflow. Dried slices of shallot were stored in ambient temperature in closed glass containers, and quercetin was determined periodically. The process of drying and further 8 months of storage caused a small decrease (15 - 16%) of the quercetin level in shallot. During the process of freezing of sliced shallot and its subsequent storage over 8 months in temperature -21°C, the quercetin level declined slightly, too, although the decline was higher than in case of drying and storage of dried shallot

Flavonoids in white and yellow perianths and yellow anthers of tulips (Tulipa gesneriana L.)

The content of flavonoids in white and yellow perianths and yellow anthers of a few tulip cultivars were determined at the stage of full flowering. To analyses of flavonols a HPLC method was used. In anthers (yellow) of all analyzed cultivars (Oscar, Pax, Profesor Wóycicki, Biała Dama, White Virgin, Calypso, Diana) high content of quercetin (2,35 - 6,01 mg·g-1 F.W.), kaempferol (1,09 - 9,47 mg·g-1 F.W.) and apigenin (1,34 - 8,24 mg·g-1 F.W.) was found. In analyzed white perianth of cvs. Oscar and White Virgin also high content of quercetin (1,3 - 1,80 mg·g-1 F.W.) and kaempferol (1,90 mg·g-1 F.W.) was documented and only traces of apigenin was found. In the yellow perianth of cv. Profesor Wóycicki the level of quercetin and kaempferol was much lower than in perianth of cvs. Oscar and White Virgin, and apigenin was absent. Thus, yellow anthers and white and yellow perianth of tulip cultivars are a rich source of flavonols

Effect of Elicitation with Iron Chelate and Sodium Metasilicate on Phenolic Compounds in Legume Sprouts

Seven-day-old sprouts of fenugreek (Trigonella foenum-graecum L.), lentil (Lens culinaris L.), and alfalfa (Medicagosativa L.) were studied. The legume seeds and then sprouts were soaked each day for 30 min during 6 days with water (control) or mixture of Fe-EDTA and sodium silicate (Optysil), or sodium silicate (Na-Sil) alone. Germination and sprout growing was carried out at temperature 20 ± 2 °C in 16/8 h (day/night) conditions. Phenolic compounds (free, ester, and glycosides) content were determined by HPLC-ESI-MS/MS using a multiple reaction monitoring of selected ions. Flavonoids and phenolic acids were released from their esters after acid hydrolysis and from glycosides by alkaline hydrolysis. The presence and high content of (−)-epicatechin (EC) in fenugreek sprouts was demonstrated for the first time. Applied elicitors decreased the level of free EC in fenugreek and alfalfa sprouts but enhanced the content of its esters. Besides, elicitors decreased the content of quercetin glycosides in lentil and fenugreek sprouts but increased the content of quercetin and apigenin glycosides in alfalfa sprouts. The applied elicitors decreased the glycoside levels of most phenolic acids in lentil and p-hydroxybenzoic acid in fenugreek, while they increased the content of this acid in alfalfa. The mixture of iron chelate and sodium silicate had less effect on changes in flavonoid and phenolic acid content in legume sprouts than silicate alone. In general, the used elicitors increased the content of total phenolic compounds in fenugreek and alfalfa sprouts and decreased the content in lentil sprouts. Among the evaluated elicitors, Optysil seems to be worth recommending due to the presence of iron chelate, which can be used to enrich sprouts with this element

The Biological Activities of Troponoids and Their Use in Agriculture A Review

Chemical compounds containing the tropone structure (2,4,6-cycloheptatrien-1-one), in their molecule, called troponoids, characterized by a seven-membered ring, are distributed in some plants, bacteria and fungi, although they are relatively rare. ß-Thujaplicin (2-hydroxy-4-isopropyl-2,4,6-cycloheptatrien-1-one), also known as hinokitiol, is a natural compound found in several plants of the Cupressaceae family. Besides hinokitiol, related compounds were identified in Cupressaceae trees. It has been demonstrated that hinokitiol and its derivatives have various biological effects, such as antibacterial, antifungal, insecticidal, antimalarial, antitumor, anti-ischemic, iron chelating and the inhibitory activity against polyphenol oxidase activity. Activity similar to ß-thujaplicin has tropolone and its derivatives, which are not present nature. Due to the high scientific and practical interest, synthetic ß-thujaplicin and other troponoids have been produced for many years. In this review, the major biological effects of troponoids, mostly ß-thujaplicin and tropolone, on tyrosinase and polyphenol oxidase activity, ethylene production, antibacterial, antifungal and insecticidal activities, and biotransformation of ß-thujaplicin by cultured plant cells are presented. Accumulation of ß-thujaplicin and related troponoids has been shown in cell cultures of Cupressus lusitanica and other species of Cupressaceae. The biosynthetic pathway of the troponoids in plants, bacteria and fungi has been also briefly described

Effect of Elicitation with Iron Chelate and Sodium Metasilicate on Phenolic Compounds in Legume Sprouts

Seven-day-old sprouts of fenugreek (Trigonella foenum-graecum L.), lentil (Lens culinaris L.), and alfalfa (Medicagosativa L.) were studied. The legume seeds and then sprouts were soaked each day for 30 min during 6 days with water (control) or mixture of Fe-EDTA and sodium silicate (Optysil), or sodium silicate (Na-Sil) alone. Germination and sprout growing was carried out at temperature 20 ± 2 °C in 16/8 h (day/night) conditions. Phenolic compounds (free, ester, and glycosides) content were determined by HPLC-ESI-MS/MS using a multiple reaction monitoring of selected ions. Flavonoids and phenolic acids were released from their esters after acid hydrolysis and from glycosides by alkaline hydrolysis. The presence and high content of (−)-epicatechin (EC) in fenugreek sprouts was demonstrated for the first time. Applied elicitors decreased the level of free EC in fenugreek and alfalfa sprouts but enhanced the content of its esters. Besides, elicitors decreased the content of quercetin glycosides in lentil and fenugreek sprouts but increased the content of quercetin and apigenin glycosides in alfalfa sprouts. The applied elicitors decreased the glycoside levels of most phenolic acids in lentil and p-hydroxybenzoic acid in fenugreek, while they increased the content of this acid in alfalfa. The mixture of iron chelate and sodium silicate had less effect on changes in flavonoid and phenolic acid content in legume sprouts than silicate alone. In general, the used elicitors increased the content of total phenolic compounds in fenugreek and alfalfa sprouts and decreased the content in lentil sprouts. Among the evaluated elicitors, Optysil seems to be worth recommending due to the presence of iron chelate, which can be used to enrich sprouts with this element

The Biological Activities of Troponoids and Their Use in Agriculture A Review

Chemical compounds containing the tropone structure (2,4,6-cycloheptatrien-1-one), in their molecule, called troponoids, characterized by a seven-membered ring, are distributed in some plants, bacteria and fungi, although they are relatively rare. ß-Thujaplicin (2-hydroxy-4-isopropyl-2,4,6-cycloheptatrien-1-one), also known as hinokitiol, is a natural compound found in several plants of the Cupressaceae family. Besides hinokitiol, related compounds were identified in Cupressaceae trees. It has been demonstrated that hinokitiol and its derivatives have various biological effects, such as antibacterial, antifungal, insecticidal, antimalarial, antitumor, anti-ischemic, iron chelating and the inhibitory activity against polyphenol oxidase activity. Activity similar to ß-thujaplicin has tropolone and its derivatives, which are not present nature. Due to the high scientific and practical interest, synthetic ß-thujaplicin and other troponoids have been produced for many years. In this review, the major biological effects of troponoids, mostly ß-thujaplicin and tropolone, on tyrosinase and polyphenol oxidase activity, ethylene production, antibacterial, antifungal and insecticidal activities, and biotransformation of ß-thujaplicin by cultured plant cells are presented. Accumulation of ß-thujaplicin and related troponoids has been shown in cell cultures of Cupressus lusitanica and other species of Cupressaceae. The biosynthetic pathway of the troponoids in plants, bacteria and fungi has been also briefly described