Seed epicuticular wax of avena sativa

The main fractions in oat seed wax are β-diketones (15.5%), alkanols (14.4%), hydroxy-β-diketones (12.2%), esters (11.1%) and fatty esters (7.2%).     

Alkyl esters from pinus radiata foliage epicuticular wax

Wax esters from the epicuticular wax of juvenile and mature-tree Pinus radiata foliage have been shown by capillary column GC-MS to consist mainly of short chain (C₆–C₁₂)alkanols esterified with long chain acids (C₂₄–C₃₂) and long chain alkanols (C₂₄–C₃₂) esterified with short chain acids (C₆-C₁₄) in a non-random manner. Mature-tree foliage wax esters also contained nonacosan-10-ol esterified with dodecanoic and tetradecanoic acids.     

Effect of leaf age on epicuticular wax alkanes in Rhododendron

Alkane distribution pattern in epicuticular wax of Rhododendron fortunei cv Admiral Piet Hein leaves remains unchanged from the age of 6 weeks to abscission.     

UV-B辐射增强对拟南芥表皮蜡质的影响

以野生型拟南芥、蜡质不同程度缺失突变体CER1、CER3、CER4、CER6、CER10、CER20及KCS1为试验材料,通过施加50μW/cm2、长达10 d的UV-B辐射,研究了拟南芥表皮蜡质晶体结构、组分及蜡质基因对UV-B辐射的响应机制。结果表明:UVB辐射增强改变了拟南芥表皮蜡质晶体结构,表皮蜡质松针状(CER1)、柱状、杆状(CER3、CER10与KCS1)晶体结构显著减少,球状蜡质晶体类型出现在CER6表面,无规则片状、膜状结构覆盖在KCS1与CER10茎表面。野生型拟南芥蜡质晶体结构类型无明显变化,但在部分区域积累了大量水平杆状、管状结构,增加了蜡质层厚度。UV-B辐射增强也改变了拟南芥表皮蜡质组分的分泌量。野生型在UV-B处理后一级醇、酸、醛含量显著上升,烷、次级醇及酮含量显著下降,蜡质总量增加不显著。一级醇含量的增加及酮和次级醇含量的减少在拟南芥各材料响应UV-B辐射中具有普遍性。UV-B辐射增强诱导了野生型CER3、CER4、KCS1基因表达的上调,其中CER4大量表达,促进了蜡质组分中一级醇、酸和醛含量的积累;CER1在UV-B处理后表达量下调,可能导致烷合成下游分支途径相关产物(烷类、次级醇及酮类)的减少。WIN1表达量的下调对蜡质总量没有显著影响。UV-B辐射增强使蜡质前体从烷合成分支途径更多地转向一级醇分支途径。     

Alkane distribution in epicuticular wax of epacridaceae

Alkane distribution pattern was determined in the epicuticular wax of leaves of 39 species and in the flower wax of three species of Epacridaceae. Uniform patterns were observed within some genera (Monotoca, Styphelia) whereas in others no common pattern was apparent. There was no difference between the alkane patterns of the two subfamilies Epacrideae and Styphelieae. The pattern was not affected by the presence of new growth, and there was no correlation with the season, habitat, climate, nature of soil, or the presence or absence of flowers.     

p-Hydroxybenzaldehyde as a major constituent of the epicuticular wax of seedling Sorghum bicolor

p-Hydroxybenzaldehyde is present in concentrations up to 30% in the wax of Sorghum bicolor seedlings. It is highly deterrent to locusts, reducing their normal feeding by 90%.     

Hydrocarbons from epicuticular waxes of Citrus peels

The hydrocarbon fraction of the epicuticular wax layer of peel from 5 cultivars of Citrus was monitored at various stages of fruit development. GLC     

Is p-hydroxybenzaldehyde a major constituent of epicuticular wax from Sorghum bicolor seedlings?

Free p-hydroxybenzaldehyde was not present in appreciable quantity on the surface or in the interior of week-old Sorghum bicolor shoots that had been heated to inactivate hydrolytic enzymes, nor was p-hydroxybenzaldehyde detected in epicuticular wax of greenhouse-grown sorghum ca 4.5 months old.     

核盘菌侵染对拟南芥表皮蜡质结构及化学组成的影响

以野生型拟南芥与蜡质突变体cer1、cer4为试验材料,通过研究核盘菌胁迫对拟南芥茎表皮蜡质结构及组分含量的影响,揭示核盘菌侵染与表皮蜡质的关系。扫描电镜结果显示,野生型拟南芥蜡质晶体以垂直于表面的杆状、块状结构为主;突变体cer1晶体类型以水平的松针状、块状结构为主;突变体cer4蜡质晶体以垂直片层结构为主。核盘菌胁迫下,拟南芥蜡质晶体结构及分布形态发生变化。蜡质层结构在核盘菌胁迫下表现为:杆状、松针状蜡质晶体减少—蜡质晶体熔融—表皮"囊状凸起"—表皮膜层破裂。这些结构变化有利于病菌突破角质层屏障而侵入到植株体内。色质谱分析结果显示:与野生型相比,cer1突变体烷、次级醇、酮类显著减少;cer4突变体表现为一级醇含量减少。接种核盘菌后,野生型拟南芥与蜡质突变体一级醇类显著增加(cer1增加不显著);烷类、次级醇类、酮类含量与蜡质总量均显著减少,表明蜡质前体物质在受到核盘菌胁迫后更多地通过酰基还原途径生成一级醇,从而减少了由脱羰基途径所生成的蜡质组分。核盘菌通过改变表皮蜡质晶体结构与化学组分分泌量来促进侵染。     

Effect of epicuticular wax isolation method on alkane distribution pattern

The alkane distribution pattern in epicuticular wax isolated by a single immersion of leafy material in light petroleum does not differ significantly from wax obtained by two consecutive immersions at room temperature. However, was isolated by immersion in boiling light petroleum gives in some cases an alkane pattern different from the wax isolated by immersion at room temperature.     

Epicuticular wax of Triticum aestivum demar 4

The composition of epicuticular wax from plants of bread wheat (Demar 4 variety) at 3 stages of growth was studied. After germination for 30 and 130 da     

The skimmiwallinols--minor components of the epicuticular wax of Cocos nucifera

Four new skimmiwallinol derivatives, isoskimmiwallinol acetate (4), skimmiwallinol acetate (5), isoskimmiwallinone (6) and skimmiwallinone (7), along with the previously isolated major components isoskimmiwallin (2) and skimmiwallin (3), have been found in the wax extract of pinnae from Cocos nucifera. Metabolites 4 and 5 were obtained as an inseparable mixture and identified by analysis of spectroscopic data and chemical correlation with 2 and 3, respectively. Metabolites 6 and 7 were identified by GC co-injection with the corresponding synthetic derivatives prepared from 4 and 5.     

Effects of light and temperature on the composition of epicuticular wax of barley leaves

The amount of wax/cm² on expanding primary leaves of Bonus barley depends on both the photo- and thermoperiods in which the seedlings are grown. With a temperature cycle of 15–10°, transfer of dark grown leaves to the light stopped leaf expansion and after 24 hr yielded 2·5 times more wax/cm² than is characteristic for light grown leaves. This demonstrates that wax synthesis and extrusion is not directly correlated with leaf expansion. The relative amounts of the wax classes formed by the decarboxylation pathways (< 1%), the reductive pathways (89%) or only by elongation (10%) are the same in light and dark. Within the reductive pathways, however, light stimulates aldehyde formation. Both environmental parameters can strongly influence the chain length composition of the wax classes. In the light one chain length or one group of chain lengths dominates a given wax class. In the dark two prominent chain lengths or groups thereof are found. The major chain length in these two groups differs by two or more carbons.     

Leaf and stem epicuticular wax structures in Lonicera species (Caprifoliaceae)

Epicuticular waxes are found on the surface of the plant epidermis as crystal structures which show morphological diversity and may be useful in plant systematics. The aim of this study was to recognise the diversity of the epicuticular wax cover on leaves and stems of Lonicera species (Caprifoliaceae) and to estimate the taxonomic value of wax traits. Adaxial and abaxial sides of the leaves and the stem surface in 35 taxa were investigated through a scanning electron microscope (SEM). The assessment was prepared on the basis of the presence or absence of basic types of wax structures and their dimensions, using categorical response analysis, multiple correspondence analysis and cluster analysis. In the analysed species, we found differences in the wax layer structure on the surfaces of the leaves and stems. Apart from the smooth layer, tubules and platelets can be found. Tubules are considerably more frequent than platelets. In many cases, the same plant part produces more than just one wax type. Our analysis indicates that wax structures are not very informative for the taxonomy of Lonicera, because we observed only a weak correspondence between the presence or absence of some types of wax tubules and the infrageneric classification of the genus. However, in particular cases these new data can be used for species identification.     

Branched-chain constituents of Brussels sprout wax

The presence of a substantial proportion of branched, in addition to normal compounds, was confirmed in the alkyl ester and primary alcohol components     

Nonanal in epicuticular wax of golden egg plums (Prunus domestica)

Nonanal was identified, as a major component, in the aldehyde fraction of the cuticular wax of the plum cultivar, Golden Egg. This compound was found to play an important role in the overall aroma of the plum.     

Investigation of Brassica oleracea and Nasturtium officinale seeds for the presence of epithiospecifier protein

Cabbage seeds contain 5 glucosinolates and on autolysis produce, in particular, 1-cyano-2-3-epithiopropane. Watercress seeds contain 4 glucosinolates, but none capable of forming a cyanoepithioalkane. Cabbage exhibited behaviour commensurate with possession of an epithiospecifier protein (ESP) whilst watercress did not show any such activity.