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Jasmonic acid (JA) and methyl jasmonate (JA-Me) are naturally occurring growth regulators widely distributed in plants, showing various biological activities in the regulation of plant growth and development. This article reviews the effect of methyl jasmonate and/or jasmonic acid on ethylene production and some other physiological processes during ripening of tomatoes and apples, flowers senescence and ethylene production in leaves and the possible role of jasmonic acid in biosynthesis of ethylene in wounded and pathogen infected tissues. It was found that JA-Me and JA induce or stimulate ethylene production in different organs of many plants. It seems that methyl jasmonate and jasmonic acid are among the factors controlling the biosynthesis of ethylene through stimulation of ACC synthase and ACC oxidase activities.
Tomato ripening in normal red-fruited cultivar (Fiorin) was delayed by treatment with methyl jasmonate (JA-Me) vapour. A visual scoring system for describing tomato ripening was used. Surface of fruits exposed to JA-Me vapour, increased in yellow and decreased in red as deter mined by HunterLab colour meter. JA-Me significantly altered the firmness of fruits after 21 days storage. Vapour of JA-Me enhanced the level of ß-carotene in outer part (peel with 3 mm pericarp tissue) of fruit, while it had no effect in peeled fruit pericarp. JA-Me treatment decreased the level of lycopene in outer part and pericarp tissue, however, in outer part lycopene content decreased at a higher rate than in pericarp. Amount of tomatine in fruits treated with JA-Me had enhanced four-fold in outer part and by 62% in peeled fruit pericarp as compared with the control.
It was found previously that methyl jasmonate (JA-Me) induced leaf abscission in Kalanchoe blossfeldiana. In present studies it was showed that JA-Me did not affect or only slightly affected the content of free and bound fatty acids in petioles and blades. ß-Sitosterol, campesterol and ß-amyrin were identified in petioles and blades of K. blossfeldiana; JA-Me decreased the content of campesterol in petioles and increased the content of ß-sitosterol in blades. In blades of plants treated with JA-Me disappearance of olean-12-one was indicated but appearance of 2H-cyclopropa|a]-naphthalen-2-one,l, la, 4, 5, 6, 7, 7a, 7b-octahydro-1. 1, 7, 7a-tetramethyl (aristolone) was documented. The significance of these findings in leaf abscission induced by methyl jasmonate in K. blossfeldiana is discussed.
It has been shown previously that methyl jasmonate (JA-Me) applied in lanolin paste on the bottom surface of intact tulip leaves causes a rapid and intense its senescence. The aim of this work was to study the effect of JA-Me on free and bound fatty acid and sterol contents during tulip leaf senescence. The main free and bound fatty acids of tulip leaf, in decreasing order of their abundance, were linolenic, linoleic, palmitic, oleic, stearic and myristic acids. Only the ęontent of free linolenic acid decreased after treatment with JA-Me during visible stage of senescence. ß-Sitosterol (highest concentration), campesterol, stigmasterol and cholesterol were identified in tulip leaf. Methyl jasmonate evidently increased the level of ß-sitosterol, campesterol and stigmasterol during induced senescence. It is suggested that the increase in sterol concentrations under the influence of methyl jasmonate induced changes in membrane fluidity and permeability, which may be responsible for senescence.
It was found previously that methyl jasmonate (JA-Me) induced leaf abscission in Kalanchoe blossfeldiana. In present studies it was shown that JA-Me markedly increased the total activities of cellulase, polygalacturonase, pectinase and xylanase in petioles, but did not affect activities of these enzymes in the blades and apical part of shoots of K. blossfeldiana. These results suggest that methyl jasmonate promotes the degradation of cell wall polysaccharides in the abscission zone and in this way induces leaf abscission in Kalanchoe blossfeldiana. Aktywność glukanaz rozkładających ściany komórkowe w czasie indukowanego odpadania liści u Kalanchoe blossfeldiana przez ester metylowy kwasu jasmonowego.
Metodę mikrorozmnażania tulipana opracowano dla potrzeb hodowli twórczej i zachowawczej. Celem prezentowanych badań było zwiększenie efektywności formowania i jakości cebul w kulturach pędów in vitro. W badaniach wykorzystano pędy odmiany ‘Blue Parrot’, która w warunkach in vitro formuje cebule niskiej jakości. Badano wpływ kwasu 1-aminocyklopropano-l-karboksylowego (ACC), kwasu 2-chloroetylo-fosfonowego, CEPA), kwasu indolilo-3-octowego (IAA) oraz estru metylowego kwasu jasmonowego (MeJA) na liczbę i masę uzyskanych cebul in vitro oraz efektywność formowania cebul (procent pędów formujących cebule wysokiej jakości nadających się do ukorzeniania). Związki te dodawano oddzielnie lub łącznie do kultur pędów rosnących na zestalonych pożywkach agarowych po 4 (CEPA) lub 8 tygodniach (wszystkie związki) od zakończenia 14-tygodniowego chłodzenia (niska temperatura indukuje proces tuberyzacji). Wykazano, że IAA oraz MeJA istotnie stymulowały formowanie cebul. W kontroli efektywność procesu formowania cebul wynosiła 20%. W kulturach pędów traktowanych IAA notowano nawet większą liczbę wszystkich cebul od liczby tworzących je pędów, jednakże tylko 49% pędów wytworzyło cebule wysokiej jakości (przy stężeniu IAA 2,5 mg‧dm⁻³). Najwięcej takich wartościowych cebul wytworzyły pędy traktowane samym MeJA w stężeniu 25 i 50 µl‧dm⁻³, odpowiednio 55,5% i 61,0%. Spośród traktowań ACC i CEPA, dwukrotnie zastosowanie CEPA w stężeniu 1 mg‧dm⁻³ poprawiło efektywność formowania cebul z 7,5% (kontrola) do 42,5%. Cebule najwyższej jakości (okryte tuniką i z wąską szyjką) notowano w obecności samego MeJA.
The yellowish-tangerine tomato (cv. Bursztyn) in the green, light yellow and yellow stages of ripening were treated with 0.1% and 1.0% of methyl jasmonate (JA-Me) in lanolin paste and kept for several days and then they were evaluated for production of ethylene, ACC oxidase activity and C02 evolution. Production of endogenous ethylene in mature green fruits was low and increased during ripening. JA-Me stimulated ethylene production and ACC oxidase activity in all investigated stages of fruit ripening. Slices excised from mature green fruits produced highest amount of carbon dioxide as compared to more advanced stages of ripening. JA-Me in 0.1% and 1.0% concentrations increased significantly C02 evolution in green fruits, while in light yellow and yellow fruits only higher concentration of JA-Me stimulated carbon dioxide production. Wpływ estru metylowego kwasu jasmonowego na produkcję etylenu, aktywność oksydazy ACC i wydzielanie dwutlenku węgla w owocach żółto-pomarańczowej odmiany pomidorów
Apples cv. Jonagold were harvested at the beginning of October and stored at 0°C until treatment between the beginning of December and the end of January. Methyl jasmonate (JA-Me) at the concentration of 1.0, 0.5, 0.1, 0.05, and 0.01 % in lanolin paste were applied to the surface of intact apples. During five days from treatment, samples of cortex with skin (area about 2.0 cm2) were cut off at a depth of about 2 mm and used for determination of ethylene production, ACC oxidase activity and respiration determined as CO, evolution. The production of endogenous ethylene was highest at mid-January (100, 280, and 250 nl/g*h at December, mid-January, and the end of January, respectively). During December and at the beginning of January, JA-Me initially (1-2 days after treatment) stimulated ethylene production and then the production was inhibited. The lower concentration of JA-Me caused initially the greater stimulation and then lower inhibition of ethylene production. However, at the time of maximum production of endogenous ethylene (mid-January) and later, stimulatory effect of JA-Me disappeared. The effect of various concentrations and time of application of JA-Me on ACC oxidase activity had similar trend as endogenous ethylene production. Methyl jasmonate stimulated respiration and this effect was dependent on JA-Me concentration and independent on time of application. The metabolic significance of these findings is discussed.
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