Elicitor-induced phenylalanine-ammonia lyase,cinnamic acid 4-hydroxylase andp-coumaroyl transferase activity inEphedra distachya cultures

Ephedra distachya cultures have been known to accumulatep-coumaroylamino acids by elicitor treatment. Based on their chemical structures, the biosynthetic pathway ofp-coumaroylamino acids was postulated and phenylalanine ammonia-lyase (PAL), cinnamic acid 4-hydroxylase (4-CH) andp-coumaroyl CoA: D-Alap-coumaroyltransferase (p-CT) were supposed to be involved in the pathway. The time course inductions of these enzymes were investigated after treatment of yeast extract, yeast-derived mannan glycopeptide and D-Ala. They, were detectable at only 4 hours and reached to their maximum level at 9 hours after onset of elicitor treatment. The activities of PAL and 4-CH were almost disappeared within 24 hours, however, that ofp-CT was remained up to 48 hours irrespective of the kind of elicitors.p-CT showed substrate specificity to D-Ala at crude enzyme extract level.     

丹参毛状根中多种丹酚酸类化合物的鉴定与生物合成(英文)

应用发根农杆菌9402侵染丹参叶片获得了一株可以稳定产生多种丹酚酸类化合物的丹参毛状根。除迷迭香酸和丹酚酸B外还含有丹酚酸K、丹酚酸L、乙基丹酚酸B、甲基丹酚酸B以及一个分子量为538的未知化合物(化合物538)。LC-MS对这些化合物进行了鉴定。对茉莉酸甲酯(MeJA)和酵母诱导子对几种主要化合物积累的影响进行了分析:MeJA促进丹酚酸B、迷迭香酸、丹酚酸K和化合物538的积累,分别从干重4.21%、2.48%、0.29%和0.01%提高到7.11%、3.38%、0.68%和0.04%;酵母诱导子提高迷迭香酸含量,从干重2.83%上升到5.71%,抑制了丹酚酸B、丹酚酸K和化合物538的生物合成。实验结果表明所获得的丹参毛状根可以作为生产丹酚酸B、迷迭香和丹酚酸K以及化合物538的替代资源。对这些酚酸类化合物对诱导子的生物累积效应变化趋势进行分析推测:丹参毛状根中丹酚酸K和化合物538可能是从迷迭香酸合成丹酚酸B的中间产物。     

Ascorbic acid induces furanocoumarin production in organ cultures of Glehnia littoralis

Exogenously supplied ascorbic acid (AsA) strongly induced furanocoumarin production in leaf and root cultures of GLEHNIA LITTORALIS, but not in cell suspension cultures, after 24 h of treatment. The dose dependency showed that both organ tissues responded well to AsA supplied at concentrations of 10 - 40 mM. For induction of furanocoumarin production, roots required contact with AsA for at least 6 h and productivity markedly increased after 8 h of treatment. This is the first report of the induction of furanocoumarin biosynthesis by AsA alone and of the detection of furanocoumarin biosynthesis in a root culture system.     

Effects of lead on the growth, lead accumulation and physiological responses of Pluchea sagittalis

This work aimed to study the process of stress adaptation in root and leaves of different developmental stages (apex, middle and basal regions) of Pluchea sagittalis (Lam.) Cabrera plants grown under exposure to five Pb levels (0, 200, 400, 600 and 1000 μM) for 30 days. Pb concentration and content in roots, stems, and leaves of different developmental stages increased with external Pb level. Consumption of nutrient solution, transpiration ratio, leaf fresh weight, leaf area, and shoot length decreased upon addition of Pb treatments. However, dry weight of shoot parts and roots did not decrease upon addition of Pb treatments. Based on index of tolerance, the roots were much more tolerant to Pb than shoots. δ-aminolevulinic acid dehydratase activity was decreased by Pb treatments, whereas carotenoid and chlorophyll concentrations were not affected. Lipid peroxidation and hydrogen peroxide concentration both in roots and leaves increased with increasing Pb levels. Pb treatments increased ascorbate peroxidase activity in all plant parts, while superoxide dismutase activity increased in leaves and did not change in roots. Catalase activity in leaves from the apex shoot was not affected by Pb, but in other plant parts it was increased. Pb toxicity caused increase in non-protein thiol groups concentration in shoot parts, whereas no significant difference was observed in roots. Both root and shoot ascorbic acid concentration increased with increasing Pb level. Therefore, it seems that Pb stress triggered an efficient defense mechanism against oxidative stress in P. sagittalis but its magnitude was depending on the plant organ and of their physiological status. In addition, these results suggest that P. sagittalis is Pb-tolerant. In conclusion, P. sagittalis is able to accumulate on average 6730 and 550 μg Pb g⁻¹ dry weight, respectively, in the roots and shoot, a physiological trait which may be exploited for the phytoremediation of contaminated soils and waters.     

Phytochemical studies of the phenolic substances in <Emphasis Type="Italic">Aster glehni</Emphasis> extract and its sedative and anticonvulsant activity

On high performance liquid chromatography, the caffeoylquinic acid (CQ) occupying the highest proportion of the water-ethanol (7:3) extract of Aster glehni (Compositae) leaves was 3-Op-coumaroylquinic acid (46.10 ± 4.22 mg/g of dried weight) among CQs tested. The IC50 of the water-ethanol (7:3) extract was 4.23 ± 0.24 μg/mL in the peroxynitrite (ONOO⁻)-scavenging assay. Phytochemical isolation from A. glehni extract yielded three kaempferol glycosides. The water-ethanol (7:3) extract and both p-coumaric acid and caffeic acid, phenylpropanoid moieties of CQs, had sedative effects in pentobarbital-induced sleeping time in mice and anticonvulsant effects in pentylenetetrazole-induced mice. Furthermore, the phenolic substance-rich W-E (7:3) extract of A. glehni could be used to treat anxiety or convulsion partly due to its peroxynitrite-scavenging mechanism.     

Identification of major aroma compounds in the leaf of <Emphasis Type="Italic">Morinda citrifolia</Emphasis> Linn.

Morinda citrifolia, commonly named noni, has been used as food and as a folk medicine throughout the tropics. The use of the leaves to make hot water beverages is increasing in popularity, especially in Japan and the United States. To better understand the effects of processing on the content of the major aroma compounds, volatile oils were collected from samples of frozen, dried and roasted leaves by steam distillation and then analyzed by GC-MS. Drying of the leaves reduces the quantity of aroma compounds by more than half. Palmitic acid and E-phytol were identified as the major components of the volatile oil. With the exception of E-phytol, all of the known volatile compounds identified in the leaf samples were done so for the first time.     

Composition and seasonal variation of essential oil in <Emphasis Type="Italic">Alpinia zerumbet</Emphasis> from Okinawa Island

The composition of steam-distilled essential oils from the leaves of Alpinia zerumbet (Pers.) B. L. Burtt. et R. M. Sm. cultivated in Okinawa Island was investigated by GC-MS analysis. The seasonal variation of the main volatile constituents was also investigated. Analysis of the essential oil identified 17 compounds. It showed the predominant presence of monoterpenic constituents, representing 95% of the essential oil. p-Cymene was the most abundant compound, followed by 1,8-cineole, terpinen-4-ol, alpha-pinene, beta-pinene and limonene. The amount of sesqiterpenic content of the essential oil was small, mostly represented by beta-caryophyllene and alpha-caryophyllene. One of the phenylpropanoid derivatives, methyl cinnamate, was also detected. The essential oils from the leaves collected at ten different collection periods for over 5 years showed significant differences in their compositions. p-Cymene, terpinen-4-ol and 1,8-cineole were the most predominant constituents over the periods with a few exceptions. The content rates of p-cymene were abundant in summer, still high in late autumn and early winter, and decreased in mid-winter and early spring. In contrast, the contents of terpinen-4-ol and 1,8-cineole were high in winter, but decreased around summer. On enantiomeric distribution, terpinen-4-ol and alpha-pinene were suggested to relate to seasonal transformation. (+)-Terpinen-4-ol had a tendency to decrease in high temperatures and huge precipitations. It was also suggested that (−)-alpha-pinene was more sensitive to climate change than (+)-alpha-pinene.     

Changes in uptake of calcium caused by phytotoxicity of cadmium in Salvinia molesta

The effect of Ca on the uptake of Cd by root and leaves of Salvinia molesta was investigated at different time intervals and under different photoperiods. For detailed study on uptake and interaction, ¹⁵Ca and ¹⁰⁹Cd were used and it was found that there was a higher uptake of ⁴⁵Ca in the root and leaves at 48 h and a concurrent reduction in ¹⁰⁹Cd content at 48 h suggesting alterations in Ca functions due to the phytotoxicity of Cd. Ultrastructural changes due to cadmium toxicity included swirling of thylakoid membranes of the chloroplasts as well as detachment of the tips of trichomes from the leaf.     

Essential oils of petal,leaf and stem of the antimalarial plant <Emphasis Type="Italic">Artemisia annua</Emphasis>

The chemical composition of the essential oils obtained from petals, leaves and stems of the flowering stage of plants of Artemisia annua cultivar Jwarharti was analyzed by gas chromatography mass spectrometry (GC-MS); 86, 77, and 63 compounds were identified in the leaf, petal, and stem oils, respectively. Large compositional differences were detected between the three oils. The petal and leaf oils were rich in monoterpenes. The stem oil was rich in sesquiterpenes. Camphor, present in the leaf oil, was absent from petal oil.