Characterization of Chemical Components in Organs Emissions of Two Salvia dominica L. Populations from Jordan.

The current investigation reports the chemical composition of volatile organic compounds emitted from the different aerial organs of two populations of Salvia dominica L. from Jordan collected from Mediterranean and Irano-Turanian bio-geographical zones. Oxygenated monoterpenes dominated the emission profiles of most organs from the two populations but with variable qualitative and quantitative differences. Mediterranean samples contained higher content of oxygenated monoterpenes (stems: 88.37%, leaves 89.95%, pre-flowering buds 67.14%, fully opened flowers 79.43%, sepals 90.93% and petals 92.25%) as compared to those from Irano-Turanian origin (range 39.85% to 75.06%). trans-Sabinene hydrate dominated the emission profiles of all organs from Irano-Turanian zone (range 38.54% to 73.24%) in addition to the stem, sepal and petal samples from the Mediterranean zone (51.37% to 86.98%). The other organs from the Mediterranean zone were dominated by α-terpenyl acetate (27.66-54.87%). Cluster and Principle Component statistical analysis classified the two populations into two clusters based on their origin. The current study evidenced the different VOCs composition in the two populations, that was mainly related to climatic and environmental conditions and suggested the presence of two ecotypes of S. dominica L.in Jordan.

Pollinator shifts, contingent evolution, and evolutionary constraint drive floral disparity in Salvia (Lamiaceae): Evidence from morphometrics and phylogenetic comparative methods.

Switches in pollinators have been argued to be key drivers of floral evolution in angiosperms. However, few studies have tested the relationship between floral shape evolution and switches in pollination in large clades. In concert with a dated phylogeny, we present a morphometric analysis of corolla, anther connective, and style shape across 44% of nearly 1000 species of Salvia (Lamiaceae) and test four hypotheses of floral evolution. We demonstrate that floral morphospace of New World (NW) Salvia is largely distinct from that of Old World (OW) Salvia and that these differences are pollinator driven; shifts in floral morphology sometimes mirror shifts in pollinators; anther connectives (key constituents of the Salvia staminal lever) and styles co-evolved from curved to linear shapes following shifts from bee to bird pollination; and morphological differences between NW and OW bee flowers are partly the legacy of constraints imposed by an earlier shift to bird pollination in the NW. The distinctive staminal lever in Salvia is a morphologically diverse structure that has evolved in concert with both the corolla and style, under different pollinator pressures, and in contingent fashion.

The effect of sowing time on the growth of chia (Salvia hispanica L.): What do nonlinear mixed models tell us about it?

Chia (Salvia hispanica L.) is an annual short-day plant whose growth has not been studied extensively in low-altitudes and at temperatures outside of its optimal range. The objective of this study was to describe the growth dynamics of a chia crop from an experimental plantation in south-east Mexico, on three different sowing dates. The chia grew at temperatures (18-37°C) and an altitude (9 m a.s.l.) outside of the recommended conditions (20-30°C, 500-1000 m a.s.l.). Three individual-plant responses were measured weekly, before seed harvest: height, number of leaves and number of inflorescences. Three theoretical nonlinear growth models were fitted to the data, a different model for each response. Mixed-effect model parameters were estimated by maximum likelihood, and the goodness of fit for each model was evaluated using two criteria: Modeling Efficiency and Root Mean Square Error. Chia seed yield was also measured in each treatment. Estimated parameters for plant height confirmed that medium sowing time (MST) and late sowing time (LST) plants had smaller heights than the early sowing time (EST) plants. Moreover, at the end of their life cycle, EST plants had a greater number of leaves and inflorescences, and higher seed yield. All of these differences were associated to the extended time of vegetative growth of EST plants favored by optimal photoperiod and temperature. Growth dynamics of chia during its ontogenic phases was explored, in more detail, with relative growth parameters derived from fitted models: a decrease in photoperiod influences the beginning of the reproductive phase, with the consequent reduction in speed of vegetative growth. In addition, nonlinear mixed-effects models can be useful in understanding the relation between growth parameters, plant maturity, and the suitable time for chia seed harvest. Our results suggest chia crops are adaptable to non-conventional environmental conditions.

Phylogeny and staminal evolution of Salvia (Lamiaceae, Nepetoideae) in East Asia.

Background and Aims: Salvia is the largest genus within Lamiaceae, with about 980 species currently recognized. East Asia, with approx. 100 species, is one of the three major biodiversity centres of Salvia. However, relationships within this lineage remain unclear, and the staminal lever mechanism, which may represent a key innovation within the genus, has been understudied. By using six genetic markers and nearly comprehensive taxon sampling, this study attempts to elucidate relationships and examine evolutionary trends of staminal development within the East Asia (EA) Salvia clade. Methods: Ninety-one taxa of EA Salvia were sampled and 34 taxa representing all other major lineages of Salvia were included for analysis. Two nuclear [internal transcribed spacer (ITS) and external transcribed spacer (ETS)] and four chloroplast (psbA-trnH, ycf1-rps15, trnL-trnF and rbcL) DNA markers were used for phylogenetic analysis employing maximum parsimony (MP), maximum likelihood (ML) and BEAST, with the latter also used to estimate divergence times. Key Results: All Salvia species native to East Asia form a clade, and eight major subclades (A-G) were recognized. Subclade A, comprising two limestone endemics (S. sonchifolia and S. petrophila), is sister to the remainder of EA Salvia. Six distinct stamen types were observed within the EA clade. Stamen type A, with two fully fertile posterior thecae, only occurs in S. sonchifolia and may represent the ancestral stamen type within EA Salvia. Divergence time estimates showed that the crown of EA Salvia began to diversify approx. 17.4 million years ago. Conclusions: This study supports the adoption of a broadly defined Salvia and treats EA Salvia as a subgenus, Glutinaria, recognizing eight sections within this subgenus. Stamen type A is ostensibly plesiomorphic within EA Salvia, and the other five types may have been derived from it. Staminal morphology has evolved in parallel within the EA Salvia, and staminal structure alone is inadequate to delimit infrageneric categories.

GEOMETRIC, VOLUMETRIC, COLOUR AND FRICTIONAL PROPERTIES OF SELECTED SALVIA SPECIES OF TURKEY.

BACKGROUND: Salvia seeds are promite to dietary and healthy oils because they contain essential fatty acids. Salvia seeds frequently produce mucilage on soaking, and this mucilage is used for the treatment of eye diseases in eastern countries. Salvia species studied for medicine, food and cosmetics, have the potential to be used in the various fields. In the present study, selected engineering (geometrical, volumetrical, colour and frictional) properties of 6 Salvia species seeds were determined and compared. MATERIALS AND METHODS: This study was performed on selected engineering properties of seeds of 6 Salvia species (Salvia viridis L., Salvia aethiopis L., Salvia cryptantha Montbert & Aucher ex Benthan., Salvia tomentosa Mill., Salvia sclarea L., Salvia virgata Jacq.,) cultivated in Turkey. Plants were collected during the vegetation in 2012-2013 (May-Agust). The seeds were cleaned from foreign matter, dirt and broken seeds manually. RESULTS: The average length, width and thickness were found in the range of 2.61 to 3.53 mm, 1.59 to 2.92 mm and 1.14 to 2.52 mm, respectively. Salvia viridis L. specie had the lowest geometric mean diameter and surface area, whereas Salvia cryptantha L. had the least values among these 6 Salvia species for these properties. The bulk density, true density and the porosity were between 296.83 and 702.80 kg m-3, 285.69 and 718.08 kg m-3, 10.27 and 44.05%, respectively. The volume of unit seed and sphericity ranged between 2.56 and 13.64 mm3, 62.90 and 90.40%, respectively. The coefficient of friction of salvia species were largely influenced by the friction surfaces studied, and highest values were found for polywood in the Salvia crytantha L.. In the study, the static friction coefficient and the angle of repose of salvia species changed from 0.477 to 0.955, and from 14.09 to 23.57°, respectively. CONCLUSION: Determination of geometric, volumetric, colour and frictional properties of Salvia spp. seeds may increase their economic value.

Time to split Salvia s.l. (Lamiaceae) - New insights from Old World Salvia phylogeny.

AIMS: Salvia L. is widely known as the largest genus in the mint family. A morphological modification of the androecium (lever-like stamens) was used to support this genus. However, molecular data revealed that Salvia is polyphyletic. Since phylogenetic studies largely underrepresented Old World Salvia species, we filled this gap and combined new data with existing sequences. The aim of our study was the identification of well-supported clades that provide the basis for evolutionary and taxonomic conclusions. METHODS: We included ITS data (internal transcribed spacer) from 220 Salvia species, 86 of which were sequenced for the first time. Additionally, the highly variable plastid marker rpl32-trnL was sequenced, providing new data for 100 Salvia species. These sequences were combined with the accessions available from GenBank. Old World Salvia is represented herein with 57% of its species. The two datasets were analyzed separately using BI and ML approaches. RESULTS: Our data confirm that Salvia is polyphyletic with four distinct evolutionary lineages (Clade I-IV), including five additional genera. The clades strongly reflect the geographical distribution, i.e., Clade IV (East Asia), Clade III (Southwest Asia to Northern Africa), and Clade II (America). The origin of Salvia s.s. (Clade I) is most likely Southwest Asia. A high degree of parallel character evolution was identified in most of the Old World sections. Based on our results, we reconstructed the evolution and biogeography of Salvia s.l. and propose to split this large group into six genera, each supported by geographical distribution, morphology, and karyology. CONCLUSION: Salvia s.l. is a polyphyletic group that was originally regarded as a genus because its species share a derived stamen structure. However, phylogenetic data clearly indicate that this floral trait and other morphological characters evolved in parallel. Our study illustrates that the combination of different data sets allows a comprehensive reconstruction of taxa and characteristic evolution, both of which are a precondition for future revision.

[Herbal textural and original plants research on medicines from Salvia in China].

On the basis of review and study on literatures of Chinese medicine, combining the history of medicinal plants of Salvia in China, and investigating the morphological description, geography distribution and therapeutic effects, herbal textural research were carried on the medicinal plants from Salvia. The results showed that the original plant of Danshen is S. miltiorrhiza and related species, the original plant of Dian Danshen is S. yunnanensis, the original plant of Li Zhi Cao is S. plebeia, the original plant of Shi Jian Chuan is Bidens pilosa. or S.chinensis, the original plant of Shu Wei Cao is S. japanica, the original plant of Ye Xia Hong is S. kiangsiensis. And the article aimed to point out the relationship of medicinal plants from Salvia and provided new insight and proof to explore the new natural medicine from medicinal plants of Salvia.

Annular floral nectary with oil-producing trichomes in Salvia farinacea (Lamiaceae): Anatomy, histochemistry, ultrastructure, and significance.

PREMISE OF THE STUDY: Many angiosperms produce nectar that entices pollinator visits. Each floral nectary tends to embody a singular form, such as the receptacular ring arising beneath the ovary in mint flowers (Lamiaceae). Exceptionally, the annular floral nectary in Salvia farinacea possesses modified stomata plus secretory trichomes. This first study of nectary ultrastructure within the largest genus of Lamiaceae examined this unusual condition. METHODS: Nectary anatomy, histochemistry, and ultrastructure were investigated from fresh and fixed material using light microscopy and scanning electron and transmission electron microscopy. KEY RESULTS: The annular nectary encircled the ovary plus extended ventrally as a projection. Modified stomata occurred only in the projection's abaxial epidermis. Conversely, peltate trichomes with a basal cell, a stalk cell, and 4-7 head cells were interspersed among the ovary lobes and covered the projection's adaxial surface. Phloem and xylem supplied the nectary interior, where parenchyma cells had numerous mitochondria and plastids with little starch, but few dictyosomes and little endoplasmic reticulum. Nectar accumulated as a drop opposite the projection's abaxial surface, escaping through stomatal pores and probably the cuticle. However, the annular nectary's glistening trichomes secreted a Sudan-positive product largely retained below the distended cuticle, but not nectar. CONCLUSIONS: This first ultrastructural study of co-occurring secretory trichomes and modified stomata on a mint nectary suggests multiple interactive functions for this atypical structure. These trichomes-possibly generating a substance informative to pollinators or as an ovarian defense against phytophagy-produced oil in an aqueous milieu, rather than contributing fluid to nectar.

[Anatomical characteristics of laminae and petioles of 11 species of Salvia and their taxonomic significance].

Anatomical features of the lamina and petiole of 11 species of Salvia had been compared. The microstructures of 11 species of Salvia were observed by paraffin method, and indexes such as the epidermis, xylems and phloems were measured. The data set was analyzed by principal components analysis method and cluster analysis method. The results indicated that the laminae of 11 species of Salvia were bifacial leaf, and the surface of laminae and petioles were covered with villous. The upper epidermis and lower epidermis of the laminae of 11 species of Salvia were constituted by a dense cuticular layer without stratum corneum. Differences existed in the structure of cross sectio mn of laminae and petioles of 11 species of Salvia. Among them, upper epidermal thickness of nine different micromorphological characters could serve as one of the criteria to identify species of taxonomic Salvia. The identification of genetic relationship of these characters in Salvia were discussed in the paper to provide an evidence of anatomy in Salvia.

The evolution of signal-reward correlations in bee- and hummingbird-pollinated species of Salvia.

Within-individual variation in floral advertising and reward traits is a feature experienced by pollinators that visit different flowers of the same plant. Pollinators can use advertising traits to gather information about the quality and amount of rewards, leading to the evolution of signal-reward correlations. As long as plants differ in the reliability of their signals and pollinators base their foraging decisions on this information, natural selection should act on within-individual correlations between signals and rewards. Because birds and bees differ in their cognitive capabilities, and use different floral traits as signals, we tested the occurrence of adaptive divergence of the within-individual signal-reward correlations among Salvia species that are pollinated either by bees or by hummingbirds. They are expected to use different floral advertising traits: frontal traits in the case of bees and side traits in the case of hummingbirds. We confirmed this expectation as bee- and hummingbird-pollinated species differed in which specific traits are predominantly associated with nectar reward at the within-individual level. Our findings highlight the adaptive value of within-individual variation and covariation patterns, commonly disregarded as 'environmental noise', and are consistent with the hypothesis that pollinator-mediated selection affects the correlation pattern among floral traits.

Vegetative anatomy and micromorphology of Salvia divinorum (Lamiaceae) from Mexico, combined with chromatographic analysis of salvinorin A.

Salvia divinorum--a species traditionally cultivated in Oaxaca, Mexico--possesses hallucinogenic properties. It is legally recognized as a controlled substance and prohibited in many countries. The proper identification of the plant, both in fresh and dried forms, is an important issue in crime-prevention campaigns. This paper provides a thorough anatomical description of leaves, petioles, and stems of S. divinorum. Detailed investigation of foliar trichomes was performed and illustrated. In addition, chromatographic analyses, including TLC and HPLC, were applied to fresh and dried plant material, together with the standard reference salvinorin A. A comprehensive identification method for S. divinorum based on a thorough anatomical examination is proposed, combined with chemical analysis for proper plant recognition.

Contrasting seasonal overlaps between primary and secondary growth are linked to wood anatomy in Mediterranean sub-shrubs.

Whole-plant approaches allow quantification of the temporal overlap between primary and secondary growth. If the amount of time available to grow is short, there may be a high temporal overlap between shoot growth and wood formation. We hypothesise that such overlap depends on the duration of the growing season and relates to wood anatomy. We evaluated wood anatomy, shoot longitudinal and radial growth rates, fine root production and the concentrations of non-structural carbohydrates (NSC) in the wood of six sub-shrub species growing in sites with contrasting climatic conditions (Lepidium subulatum, Linum suffruticosum, Salvia lavandulifolia, Satureja montana, Ononis fruticosa, Echinospartum horridum). Sub-shrub species living in sites with a short growing season displayed a high overlap between aboveground primary and secondary growth and formed wide vessels, whereas species from the warmest and driest sites presented the reverse characteristics. The highest overlap was linked to a rapid shoot extension and thickening through the enhanced hydraulic conductivity provided by wide vessels. The reductions in NSC concentrations when growth peaked were low or moderate, indicating that sub-shrubs accumulate NSC in excess, as do trees. The temporal overlap among primary and secondary growth in woody plants may be connected to the duration and rates of shoot and wood growth, which in turn depend on the vessel lumen area.

Morphoanatomical and phytochemical studies of Salvia lachnostachys (Lamiaceae).

Salvia lachnostachys Benth., Lamiaceae, is a endemic species from southern Brazil. The essential oil of its leaves and flowers is mainly constituted by aliphatic compounds, such as dodecanoic acid, with sesquiterpenes as minor constituents. This work evaluated the morphology, anatomy, microchemistry, and phytochemistry of S. lachnostachys to provide advanced knowledge of Brazilian plants with medicinal potential. Light and scanning electron microscopy techniques were used in the anatomical and microchemical studies. Compounds were isolated by chromatographic techniques, identified by analysis of their NMR spectra and compared with published data. S. lachnostachys can be distinguished from other related species mainly by its petiolate leaves, terminal inflorescence, persistent bracts, and villous-glandular corolla. The stem and leaves of S. lachnostachys display anatomical characteristics common to the family Lamiaceae. However, this species can be distinguished from other family members by the morphology and the presence of eglandular and glandular trichomes, as well as the organization of the vascular bundles of the petiole. The phytochemical results revealed that S. lacnostachys produces oleanolic and ursolic acids in addition to the diterpene fruticuline A, which is a rare compound, previously found only in Salvia fruticulosa Benth. and S. corrugata Vahl. Ursolic and oleanolic acids are bioactive triterpenes that exhibit antiatherosclerotic, anticancer, antihypertensive, antinflammatory, antileukemic, antimutagenic, antioxidant, antiproliferative, and antiviral activities, and fruticuline A has antibacterial activity.

Caracterización morfoanatómica de hoja, tallo, fruto y semilla de Salvia hispanica L. (Lamiaceae ) / Morphoanatomical characterization of Salvia hispanica L. (Lamiaceae ) leaf, stem, fruit and seed

The "chía", Salvia hispanica L. (Lamiaceae), is an herbaceous annual plant native to Mexico. Its fruits contain antioxidant substances important for human nutrition, such as linoleic and alpha-linolenic acids, natural sources of omega-3 and omega-6 acids. The aim of this work was to establish morphological and anatomical diagnostic characters for leaf, stem, fruit and seed of the species in order to contribute to the botanical quality control in the marketing process as raw material for food and/or pharmaceutical industry.

Salvia hispanica L., "chía", (Lamiaceae), es una planta herbácea, anual, originaria de México. Sus frutos contienen antioxidantes, ácido linoleico y alfa-linolénico, fuente natural de ácidos grasos omega-6 y omega-3, importantes en la nutrición humana. El objetivo de éste trabajo fue establecer caracteres morfológicos y anatómicos diagnósticos de hoja, tallo, fruto y semilla de dicha especie, a fin de contribuir al control de calidad botánico en el proceso de comercialización como materia prima para la industria alimenticia y/o farmacéutica.

Plant water status and hydraulic conductance during flowering in the southern California coastal sage shrub Salvia mellifera (Lamiaceae).

PREMISE OF THE STUDY: Plant water status during flowering is important for plant reproduction, but the physiology of floral water use is not well understood. We investigated plant water status in relation to leaf and floral physiology in naturally occurring individuals of a semiarid shrub, Salvia mellifera E. Greene. METHODS: We measured stomatal (g(s)) and corolla (g(c)) conductance to water vapor, transpiration from leaves (E(leaf)) and corollas (E(corolla)), leaf-specific hydraulic conductance (K(H)), bulk shoot water potential (Ψ(shoot)), and shoot water content on irrigated and control plants to analyze whether water was limiting to leaf and floral water use. KEY RESULTS: Experimental irrigation caused a 203% increase in soil moisture content, a 20% increase in predawn Ψ(shoot), a 29% increase in midday Ψ(shoot), and a 92% increase in K(H). Floral and leaf gas exchange did not respond significantly to water addition, indicating that rates were at seasonal maxima and not limited by water availability. Total daily water use by corollas was ∼20% of total shoot water use. There were no significant differences in total daily shoot water use with water addition. Mean shoot water content (5.07 g) was close to mean daily shoot water use (6.71 g), indicating that the equivalent of total shoot water content turned over every 0.76 d. CONCLUSIONS: These results demonstrate that although irrigation improved whole-plant hydraulic conductance, gas exchange was not limited by water availability. Additionally, the high water use of flowers in this species might limit future flowering and reproductive success during dry years.

Morphological characterisation and agronomical parameters of different species of Salvia sp. (Lamiaceae).

The aim of this work is to assess the morphological characteristics and parameters of biomass production, such as fresh and dry matter weight (FMW and DMW, g/plant), yield of dry matter (YDM) in terms of ton/ha, essential oil content (EOC, mL/100 g) and yield of essential oils (YEO) expressed as L/ha of the following plants Salvia verbenaca, Salvia argentea, Salvia lavandulifolia, Salvia pratensis, Salvia sclarea, Salvia triloba and Salvia officinalis. Except for Salvia argentea (S2) all other species have adapted to the south Brazilian climate conditions, with morphological differences among the species evaluated. In terms of DMW and YDM, S. officinalis was found to be the most productive species with 445.83 g/plant and 11.14 ton/ha. The higher essential oil content and yield was observed for S. officinalis, affording 1.99 mL/100 g and 221.74 L/ha, respectively. Chemical characterisation of the essential oils obtained from hydrodistillation was performed through GC and GC/MSD analyses, which revealed for most of the species studied, α e ß-thujone, camphor and 1,8-cineole as major compounds, apart from S. sclarea, for which linalool, linalyl acetate and α-terpineol were the major components.

Functional implications of the staminal lever mechanism in Salvia cyclostegia (Lamiaceae).

BACKGROUND AND AIMS: Flower morphology and inflorescence architecture affect pollinator foraging behaviour and thereby influence the process of pollination and the reproductive success of plants. This study explored possible ecological functions of the lever-like stamens and the floral design in Salvia cyclostegia. METHODS: Flower construction was experimentally manipulated by removing either the lower lever arms or the upper fertile thecae of the two stamens from a flower. The two types of manipulated individuals were intermixed with the control ones and randomly distributed in the population. KEY RESULTS: Removing the sterile lower lever arms significantly reduced handling time per flower of the main pollinator, Bombus personatus. Interestingly, this manipulation did not increase the number of flowers probed per plant visit, but instead reduced it, i.e. shortened the visit sequence of the bumble-bees. Both loss of staminal lever function by removing lower lever arms and exclusion of self pollen by removing upper fertile thecae significantly reduced seed set per flower and seed set per plant. Both the manipulations interacted significantly with inflorescence size for the effect on female reproductive output. CONCLUSIONS: Though the intact flowers demand a long handling time for pollinators, the reversible staminal lever is of advantage by promoting dispersal of pollen and thus the male function. The particular floral design in S. cyclostegia contributes to the floral constancy of B. personatus bumble-bees, with the lower lever arms acting as an optical cue for foraging cognition.

Hairy root cultures for secondary metabolites production.

Hairy roots (HRs) are differentiated cultures of transformed roots generated by the infection of wounded higher plants with Agrobacterium rhizogenes. This pathogen causes the HR disease leading to the neoplastic growth of roots that are characterized by high growth rate in hormone free media and genetic stability. HRs produce the same phytochemicals pattern of the corresponding wild type organ. High stability and productivity features allow the exploitation of HRs as valuable biotechnological tool for the production of plant secondary metabolites. In addition, several elicitation methods can be used to further enhance their accumulation in both small and large scale production. However, in the latter case, cultivation in bioreactors should be still optimized. HRs can be also utilised as biological farm for the production of recombinant proteins, hence holding additional potential for industrial use. HR technology has been strongly improved by increased knowledge of molecular mechanisms underlying their development. The present review summarizes updated aspects of the hairy root induction, genetics and metabolite production.

Chemical composition and biological activities of essential oil from Salvia sclarea plants regenerated in vitro.

The essential oils obtained by hydrodistillation of dried aerial parts of Salvia sclarea L. plants, regenerated in vitro and reproduced from seeds, were analyzed by GC and GC-MS. The oils from in vitro and in vivo plants were compared in respect to their chemical composition as well as antimicrobial and cytotoxic activities. The chemical profiles of both oils were very similar, although the yield of essential oil from in vitro plants was lower (0.1%, v/w) than the oil yield isolated from in vivo S. sclarea plants (0.2%, v/w). Both oils showed antimicrobial and cytotoxic activity. The oil from in vitro regenerated plants of S. sclarea exhibited stronger cytotoxic action against NALM-6 cell lines in comparison with the essential oil from in vivo plants.

Separation and on-line preconcentration by stacking and sweeping of charged analytes in the plant by microemulsion electrokinetic chromatography with nonionic surfactants.

A novel on-line technique for stacking and sweeping of long sample plugs with simultaneous determination of charged analytes in the plant (protocatechuic aldehyde, rosmarinic acid, danshensu, salvianolic acid B, and protocatechuic acid) by the nonionic microemulsion electrokinetic chromatography (MEEKC) is presented. The preconcentration efficiency provided about 9-28-fold for stacking and 7-14-fold for sweeping in the enhancements of LOD. The effects of oil phase, Brij-35 and buffer concentrations on stacking and sweeping efficiency were examined in order to optimize the two methods. In nonionic MEEKC, the effect of the type of oil and buffer contents on preconcentration mechanism is often sophisticated. This study had demonstrated that the oil type and buffer content in nonionic microemulsion indeed markedly altered the affinity of microemulsion with analytes. Finally, in comparison to the stacking method, the most apparent disadvantages of the sweeping method were the relatively high limits of detection and poor peak shapes.