热胁迫下羽叶薰衣草植物腺毛发育的超微结构

本研究利用透射电子显微镜观察热胁迫下羽叶薰衣草腺毛超微结构变化,结果表明:40℃热胁48h后,腺毛细胞中参与合成与分泌的主要细胞器受到严重破坏。质体变形,缺少基质和嗜锇物质;线粒体缺少嵴,液泡化严重;小泡不正常地融合在一起,并靠细胞壁分布;内质网呈链条状,片层似球形,核糖体显著地附在内质网片层上;细胞核出现大量的纤维状颗粒物质;分泌时期的质膜和细胞器膜等扭曲变形。说明热胁迫影响腺毛的发育与精油的分泌,从而进一步影响精油的产量和质量。     

Labiatae Novae Iranicae

Four new species are described:Lavandula sublepidota, from S. Iran (related toL. coronopifolia),Phlomis pachyphylla from S. Iran, Prov. Fars (nearPh. polioxantha),Satureia isophylla from N. Iran, Prov. Mazanderan (close toS. mutica andS. intermedia), andThymbra neurophylla from Iraqi Kurdistan (distinct forth species of the genus).

Florae Iranicae praecursores 1–4.     

The effect of growth regulators on shoot propagation and rooting of common lavender (Lavandula vera DC)

Nodal segments from micropropagated plants were used to evaluate the effect of growth regulators on the in vitro shoot proliferation and rooting of Lavandula vera DC. The highest multiplication rate was obtained using MS medium supplemented with 1.0 mg l^-1 of TDZ (2.25 μM) or BA (2 μM). Hyperhydricity occurred at high concentrations of these growth regulators. Rooting of the plantlets was obtained in all the media evaluated. However, rooting rates and root growth increased with increased concentrations of NAA and the reduction of the salt strength of the media. The plantlets were successfully transferred to soil and grown to maturity, exhibiting a normal development, with high uniformity and no evidences of somaclonal variation. This revised version was published online in June 2006 with corrections to the Cover Date.     

Decoupling subgenomes within hybrid lavandin provide new insights into speciation and monoterpenoid diversification of Lavandula

Polyploidization and transposon elements contribute to shape plant genome diversity and secondary metabolic variation in some edible crops. However, the specific contribution of these variations to the chemo-diversity of Lamiaceae, particularly in economic shrubs, is still poorly documented. The rich essential oils (EOs) of Lavandula plants are distinguished by monoterpenoids among the main EO-producing species, L. angustifolia (LA), L. × intermedia (LX) and L. latifolia (LL). Herein, the first allele-aware chromosome-level genome was assembled using a lavandin cultivar ‘Super’ and its hybrid origin was verified by two complete subgenomes (LX-LA and LX-LL). Genome-wide phylogenetics confirmed that LL, like LA, underwent two lineage-specific WGDs after the γ triplication event, and their speciation occurred after the last WGD. Chloroplast phylogenetic analysis indicated LA was the maternal source of ‘Super’, which produced premium EO (higher linalyl/lavandulyl acetate and lower 1,8-cineole and camphor) close to LA. Gene expression, especially the monoterpenoid biosynthetic genes, showed bias to LX-LA alleles. Asymmetric transposon insertions in two decoupling ‘Super’ subgenomes were responsible for speciation and monoterpenoid divergence of the progenitors. Both hybrid and parental evolutionary analysis revealed that LTR (long terminal repeat) retrotransposon associated with AAT gene loss cause no linalyl/lavandulyl acetate production in LL, and multi-BDH copies retained by tandem duplication and DNA transposon resulted in higher camphor accumulation of LL. Advances in allelic variations of monoterpenoids have the potential to revolutionize future lavandin breeding and EO production.     

Novel antiplatelet and antithrombotic activities of essential oil from Lavandula hybrida Reverchon “grosso”

Lavender extracts are known to produce several mild effects at central and peripheral level. However, no studies are so far available about the potential effects of lavender essential oil on the hemostatic system. In this work, we demonstrated antiplatelet properties of lavender oil towards platelet aggregation induced by arachidonic acid, U46619, collagen and ADP (IC₅₀=51, 84, 191 and 640 μg/ml, respectively) on guinea-pig platelet rich plasma (PRP) and its ability to destabilize clot retraction (IC₅₀=149 μg/ml) induced by thrombin on rat PRP.

Furthermore, antithrombotic properties were studied in an in vivo model of pulmonary thromboembolism induced by intravenous injection of a collagen–epinephrine mixture in mice subacutely treated with lavender oil. In this model, lavender oil (100 mg/kg/day os for 5 days) significantly reduced thrombotic events without inducing prohemorrhagic complications at variance with acetylsalicylic acid used as reference drug. Finally, main components of the oil were studied in vitro in order to assess their antiplatelet effects, but none of them possessed an activity comparable to the oil itself. These results provide the first experimental evidence of lavender oil's antiplatelet/antithrombotic properties which could be due to a synergistic effect of its components.     

Lavandula stoechas L. subsp. stoechas,a New Herbal Source for Ursolic Acid: Quantitative Analysis,Purification and Bioactivity Studies

In this study, methanol, ethanol, methanol-dichloromethane (1 : 1, v/v), acetone, ethyl acetate, diethyl ether, and chloroform extracts of lavender (Lavandula stoechas L. subsp. stoechas) were prepared by maceration, and the ursolic acid contents in the extracts were determined quantitatively by HPLC analyses. The present results show that the methanol-dichloromethane (1 : 1, v/v) solvent system is the most efficient solvent system for the extraction of ursolic acid from the plant sample with the highest yield (2.22 g/100 g plant sample). In the present study, a new practical method for the isolation of ursolic acid from polar extracts was also demonstrated for the first time. The inhibition effects of the extracts and ursolic acid were also revealed on α-glycosidase, acetylcholinesterase, butyrylcholinesterase, and human carbonic anhydrase I and II enzymes by determining IC₅₀ values for the first time. The extracts and ursolic acid acted as potent antidiabetic agents by strongly inhibiting the α-glycosidase activity, whereas they were found to be very weak neuroprotective agents. In view of the present results, L. stoechas and its major metabolite, ursolic acid, can be recommended as a herbal source to control postprandial blood sugar levels and prevent diabetes by delaying the digestion of starch in food.     

狭叶薰衣草的离体培养及挥发性成分的分析

为建立新疆狭叶薰衣草(Lavandula angustifolia)的快速繁殖体系,以种子、茎、叶为外植体,对种子萌发、愈伤组织诱导、丛芽分化和生根的最适培养条件进行了研究;用水蒸气蒸馏法提取狭叶薰衣草挥发油,采用气相色谱-质谱法测定挥发油成分。结果表明,种子浸泡的适宜时间为6 h,切开种皮培养,出芽时间最少为6 d;诱导种子出芽的适宜培养基为MS+6-BA2 mg/L;以茎为外植体诱导愈伤组织效果较好,适宜培养基为MS+6-BA 2 mg/L+2,4-D 1 mg/L;诱导分化丛芽的适宜培养基为MS+6-BA 1 mg/L+NAA 0.5 mg/L;生根的适宜培养基为1/2MS+NAA 1 mg/L+6-BA 0.5 mg/L;盆栽薰衣草和无菌苗薰衣草的挥发油主要成分相差较大,离体培养的薰衣草的主要挥发性成分有叶绿醇、丁香油烃、氧化石竹烯等。     

Chemical compounds and essential oil release through decomposition process from Lavandula stoechas in Mediterranean region

All aromatic plants emit volatile substances into the environment either during their life or during the decomposition process. During decomposition, these volatile constituents affect the top soil microflora and the nutrients recycle process. Lavandula stoechas is a perennial aromatic shrub, rich in aromatic substances which can be found abundant across the Mediterranean. The aim of the present study was to investigate the essential oil degradation during decomposition process of L. stoechas and how the essential oil major compounds are released during this process. Fresh leaves and flowers of lavender were used for this study using the litter bag technique. The essential oil content of the initial plant was 1.46% dw and after seventeen months period dropped at 0.06%. There were no differences in oil degradation among the different experimental sites. Most of the essential oil compounds had disappeared after a year. However, the most toxic compounds in the plant material still remained after seventeen months.