The Effect of Sugar Supply Rate on Photosynthetic Development of Ocimum basilicum (Sweet Basil) Cells in Continuous Culture

The fructose supply rate to continuous cultures of Ocimum basilicumL. cells was changed in two ways. The concentration of fructosein the medium feed was diminished or the dilution rate was increasedin fructose-limiting conditions. When fructose in the feed wasdecreased, whilst maintaining constant dilution rate (0.87 µ_max),the specific rate of chlorophyll production increased—thebiomass became greener. Actual photosynthesis rate (dry biomass^–1)measured in the steady state conditions also increased. When fructose supply rate was increased by increasing the dilutionrate, the specific rate of chlorophyll production and actualphotosynthesis rate (dry biomass^–1) increased until acritical dilution rate (0.64 µ_max) was reached, thereafterdecreasing. The potential photosynthesis rate was measured on samples ofcells supplied with additional photons. This was inversely relatedto dilution rate. It seemed possible that the concentration of residual fructoseoutside the cells was related to specific growth rate but probablynot according to the Monod model. The specific production ofchlorophyll may be regulated by the intracellular concentrationof a catabolite of fructose, possibly glucose. Results suggestthat the specific production rate of chlorophyll was inhibitedwhen glucose concentration in the cells was above a thresholdof about 1.2% dry biomass. The degree of inhibition was a functionof glucose concentration above this threshold. Key words: Continuous culture, Photosynthesis, Greening, Ocimum basilicum     

Photosynthetic development of Ocimum basilicum cells on transition from phosphate to fructose limitation

Continuous culture was used to establish a steady state in fructose excess. Phosphate in the Murashige and Skoog type medium was found to be limiting growth; when phosphate concentration in the medium feed was doubled, the concentration of dry biomass and of all biomass elements increased After doubling the phosphate concentration fructose became limiting. Ocimun basilicum cells responded to the transition from phosphate limitation to fructose limitation by becoming greener and more photosynthetic; consequently, the yield on fructose increased.     

Intrachloroplast Localization of 65Zn and 63Ni in a Zn-tolerant Plant, Ocimum basilicum Benth

Intrachloroplast localization studies of ⁶⁵Zn and ⁶³Ni weremade in a Zn-tolerant plant Ocimum basilicum var. purpurascensBenth. in order to investigate the mechanism and specificityof metal tolerance. The isotopes were supplied in solution tothe roots 14 d before fractionation. It was observed that ⁶⁵Znactivity was comparatively greater in the chloroplast envelopemembranes and stroma than the ⁶³Ni; and ⁶³Ni was largely foundin the lamellar and stroma fractions. Further analysis of lamellaerevealed that photosystem II (PS II) particles were richer inradioactivity than photosystem I (PS I) particles. The photochemicalevents of photosynthesis were less affected in Zn-treated plantsthan in the Ni-treated plants. The changed levels of the electrontransport chain intermediates including cytochromes, plastocyaninand ferredoxin provide supporting evidence for the localizationstudies. The activity of carbonic anhydrase, a zinc metalloprotein,was increased in Zn-treated plants with increase in nutrientZn concentration, indicating the binding of zinc to a proteinmoiety in the chloroplasts.     

RAPD and essential oil characterization of Turkish basil (Ocimum basilicum L.)

Sweet basil (Ocimum basilicum L., Lamiaceae), an important medicinal plant and culinary herb due to its delicate aroma and fragrance, shows great variation in both morphology and essential oil components. Genetic variation among basil accessions in Turkey has not been extensively examined with molecular markers. Genetic diversity was determined using random amplified polymorphic DNA (RAPD) markers of 14 genotypes of basil. A total of 375 bands were obtained from the RAPD analysis, and 273 of them (70.3 %) were polymorphic. The RAPD analysis allowed the grouping of samples into two main clusters. Genetic similarity values among the basil genotypes ranged between 0.46 and 0.87. Considerable genetic diversity was determined among basil genotypes. Essential oils were obtained by hydro-distillation and were characterized by gas chromatography. A total of 17 chemical components were identified. The evaluated genotypes of O. basilicum can be classified into seven chemotypes: (1) Linalool (7, 12, 16, 22, 25A and 33), (2) Methyl chavicol (6, 10A), (3) Citral/methyl chavicol (10L, 17), (4) Methyl eugenol (11), (5) Methyl cinnamate/linalool (23), (6) Linalool/methyl eugenol (25K), and (7) Methyl chavicol/linalool (Let). The chemical variability obtained from the essential oil composition of the genotypes in the study was remarkable. The chemical characterization of genotypes 10L and 17 was rich in citral (42.17 and 44.80 %) and methyl chavicol (30.56 and 32.03 %). Citral/methyl chavicol can be assessed as a new chemotype of basil cultivated in Turkey. The basil genotypes were grouped into two major clusters for both the RAPD analysis and chemical characterization with very few exceptions (genotype n. 6). A correlation analysis of the genetic distance matrix and the Euclidian distance matrix showed relatively low values (r = ?0.40). The results demonstrated a certain degree of correspondence between chemical and molecular data.     

Anthocyanin inheritance and instability in purple basil (Ocimum basilicum L.)

The instability of the purple pigments (anthocyanins) in purple basil varieties (Ocimum basilicum L.) limits their use as ornamental plants and as a potential anthocyanin source. Several self-pollinated generations of all purple plants were unsuccessful in stabilizing anthocyanin expression. In this study we investigated the inheritance and stability patterns of leaf traits using the Purple Ruffles variety. The results from the complete diallele crosses indicated anthocyanin expression in vegetative tissue is controlled by two dominant genes and ruffled leaf texture is controlled by a single recessive gene. Genes controlling leaf margin and leaf base structures were tightly linked to leaf texture. Essential oil production and oil constituents in leaves did not change as a result of the reversion in color. Color stability in cuttings was affected by the environment and the location where cuttings were taken. An accumulation of secondary metabolites (apigenin, genistein, and kaempferol) in green-reverted sectors on purple leaves was detected using reverse-phase high-performance liquid chromatography (HPLC) analysis; this suggested a potential block in the anthocyanin pathway. We hypothesize the reversion mutation is occurring in an anthocyanin regulatory gene.     

罗勒的组织培养和快速繁殖

1植物名称罗勒(Ocimum basilicum L.). 2材料类别顶芽或带腋芽茎段. 3培养条件基本培养基为MS培养基.(1)诱导愈伤组织培养基:MS 6-BA 4 mg·L-1(单位下同) NAA 0.1;(2)诱导丛生芽及生根培养基:MS 6-BA 3 NAA 0.5.以上培养基均含1%琼指、3%蔗糖,pH 5.6～5.8.高压灭菌锅中121℃下灭菌20 min.培养温度为23～24℃,光照时间12 h·d-1,光照度为1 000～1 500 lx.     

Patterns and mechanisms of temporal resource partitioning among bee species visiting basil (Ocimum basilicum) flowers

The way in which flower visitors share floral resources or compete for them throughout the day is a decisive factor for the effectiveness of pollination. We described daily rhythms of flower visitation by bee species and tested whether such patterns depend on: (1) the body size of the species, (2) the daily patterns of variation in weather and nectar standing crop, and (3) the effects of weather on the daily rhythm of variation in nectar standing crop. After 1 year of biweekly samplings, we encountered 56 bee species visiting basil flowers. Larger bee species were more active in the cooler and more humid hours of the morning. Smaller species foraged later, during the warmer and drier hours. Throughout the day, nectar volume decreased. In the laboratory, we determined a positive effect of increase in temperature on nectar volume, unlike the negative correlation recorded in the field. Nectar volume decreased in plants under experimental drought, showing similarity with the driest hours of the day. The daily cycle of temperature is the fundamental factor that, directly and indirectly, via air humidity, soil moisture, and nectar supply, influences bee activity according to body size and physiological attributes. In the field, the positive effect of increasing temperatures on nectar volume is masked by a stronger, negative effect of decreasing air humidity and soil moisture throughout the day.     

Photoprotection by foliar anthocyanins mitigates effects of boron toxicity in sweet basil (Ocimum basilicum)

Boron (B) toxicity is an important agricultural problem in arid environments. Excess edaphic B compromises photosynthetic efficiency, limits growth and reduces crop yield. However, some purple-leafed cultivars of sweet basil (Ocimum basilicum) exhibit greater tolerance to high B concentrations than do green-leafed cultivars. We hypothesised that foliar anthocyanins protect basil leaf mesophyll from photo-oxidative stress when chloroplast function is compromised by B toxicity. Purple-leafed ‘Red Rubin’ and green-leafed ‘Tigullio’ cultivars, grown with high or negligible edaphic B, were given a photoinhibitory light treatment. Possible effects of photoabatement by anthocyanins were simulated by superimposing a purple polycarbonate filter on the green leaves. An ameliorative effect of light filtering on photosynthetic quantum yield and on photo-oxidative load was observed in B-stressed plants. In addition, when green protoplasts from both cultivars were treated with B and illuminated through a screen of anthocyanic protoplasts or a polycarbonate film which approximated cyanidin-3-O-glucoside optical properties, the degree of photoinhibition, hydrogen peroxide production, and malondialdehyde content were reduced. The data provide evidence that anthocyanins exert a photoprotective role in purple-leafed basil mesophyll cells, thereby contributing to improved tolerance to high B concentrations.     

Shoot regeneration of young leaf explants from basil (Ocimum basilicum L.)

Summary An efficient plant regeneration protocol was successfully developed for basil (Ocimum basilicum L.). Explants from 1 mo. old seedlings yielded the highest frequency of 85% regeneration with an average of 5.1 shoots per explant. The regeneration protocol was performed on three basil varieties (Sweet Dani; methylcinnamate; Green Purple Ruffles). Callus and shoot induction was initiated on Murashige and Skoog basal medium supplemented with thidiazuron (16.8 μM) for approximately 30 d. Shoot induction and development were achieved by refreshing the induction medium after 14 d. The most morphogenetically responsive explants were from the first fully expanded true leaves of greenhouse-grown basil seedlings. All developing bud tissue demonstrated temporary anthocyanin expression; however, anthocyanin expression in Green Purple Ruffles remained stable until maturity. Developing shoots were rooted in the dark on media with thidiazuron removed. Within 20 d, rooted plantlets were transferred and acclimatized under greenhouse conditions where they developed normal morphological characteristics. This is the first report of a successful in vitro regeneration system for basil through primary callus.     

Reproductive Ecology of Ocimum americanum L. and O. basilicum L. (Lamiaceae) in India

Abstract Ocimum americanum and O. basilicum bloom once a year. They produce flowers over a long period, a few flowers being produced each day. The flowers of both are short-lived (3-4 hours), bisexual, zygomorphic, and chasmogamic with anthers dehiscing in the bud stage. The open flowers offer nectar and pollen as rewards and are visited and sternotribically pollinated by day-flying animals. The blossoms are flag-shaped, and the reproductive organs are close to the lower corolla lip. The stamens and stigma show movements immediately after anthesis and remain for 20–30 minutes and this may cause self-pollination. Both species reproduce primarily through autogamy. Flowers are open during 5:30–13:30 hr in O. americanum and during 7:00–13:00 hr in O. basilicum . Certain bee species like Apis florea, A. cerana indica, Amegilla sp., and Pseudapis oxybeloies , and the butterfly Surandra queretroum are the most frequent and consistent visitors and can be pollinators for both plant species.     

Biosorption of cesium-137 and strontium-90 by mucilaginous seeds of Ocimum basilicum

Mucilaginous seeds of Ocimum basilicum were used in uptake studies with cesium-137 and strontium-90. Results showed that uptake was dependent on the structural integrity of the mucilage fibrils. Water imbibed seeds showed higher adsorption of both 137Cs and 90Sr in comparison to seeds pretreated with NaOH, HCl and Na-periodate solution. The uptake was pH dependent and while some divalent metal ions had no or little detrimental effect, the alkali metal ions Li+, Na+ and K+ decreased the uptake. The maximum adsorption capacity was 160 mg cesium g(-1) and 247 mg strontium g(-1) seed dry weight.     

UV-B is required for normal development of oil glands in Ocimum basilicum L. (sweet basil)

Plants of Ocimum basilicum L. grown under glass were exposed to short treatments with supplementary UV-B. The effect of UV-B on volatile essential oil content was analysed and compared with morphological effects on the peltate and capitate glandular trichomes. In the absence of UV-B, both peltate and capitate glands were incompletely developed in both mature and developing leaves, the oil sacs being wrinkled and only partially filled. UV-B was found to have two main effects on the glandular trichomes. During the first 4 d of treatment, both peltate and capitate glands filled and their morphology reflected their 'normal' mature development as reported in the literature. During the following days there was a large increase in the number of broken oil sacs among the peltate glands as the mature glands broke open, releasing volatiles. Neither the number of glands nor the qualitative or quantitative composition of the volatiles was affected by UV-B. There seems to be a requirement for UV-B for the filling of the glandular trichomes of basil.     

Copper nanoparticles elevate regeneration capacity of (Ocimum basilicum L.) plant via somatic embryogenesis

Plant Cell, Tissue and Organ Culture (PCTOC) - The current work, was conducted to investigate the influences of copper nanoparticles (Cu-NPs) compared to copper sulfate on plant regeneration of...     

Somatic embryogenesis and plant regeneration from leaf callus of Ocimum basilicum L

A effective protocol for complete plant regeneration via somatic embryogenesis has been developed for Ocimum basilicum L. Callus was initiated from leaf explant of young plant on supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D) 1.0 mg l(-1), 3% sucrose and 0.9% agar. The calli showed differentiation of globular structure embryos when transferred to MS medium containing 2,4-D 0.5 mg l(-1) and BAP 1.0 mg l(-1). The maximum globular structure embryos were further enlarged and produced somatic embryos in MS basal medium supplemented with BAP 1.0 mg l(-1)+NAA 1.0 mg l(-1) + KN 0.5 mg l(-1). Continued formation of globular embryo and germination of embryos occurred in this medium. Complete plantlets were transferred onto specially made plastic cup containing soilrite followed by their transfer to the garden soil. Survival rate of the plantlets under ex vitro condition was 80%.     

Aqueous and ethanolic leaf extracts of Ocimum basilicum (sweet basil) protect against sodium arsenite-induced hepatotoxicity in Wistar rats

We evaluated the effects of aqueous and ethanolic leaf extracts ofOcimum basilicum (sweet basil) on sodium arsenite-induced hepatotoxicity in Wistar rats. We observed that treatment of the animals with the extracts before or just after sodium arsenite administration significantly (p < 0.05) reduced mean liver and serum γ-Glutamyl transferase (γGT), and serum alkaline phosphatase (ALP) activities when compared with the group administered the toxin alone. In addition, treatments of the animals with aqueous or ethanolic extract of O. basilicum before the administration of sodium arsenite resulted in the attenuation of the sodium arsenite-induced aspartate and alanine aminotransferase activities: ALT (from 282.6% to 167.7% and 157.8%), AST (from 325.1% to 173.5% and 164.2%) for the group administered sodium arsenite alone, the aqueous extracts plus sodium arsenite, and ethanolic extracts plus sodium arsenite respectively, expressed as percentage of the negative control. These findings support the presence of hepatoprotective activity in the O.basilicum extracts.     

Changes in the antioxidative systems of Ocimum basilicum L. (cv. Fine) under different sodium salts

The effects of different sodium salts on some physiological parameters and antioxidant responses were investigated in a medicinal and aromatic plant, Ocimum basilicum L. (cultivar Fine). Plants were subjected to an equimolar concentration of Na₂SO₄ (25?mM) and NaCl (50?mM) for 15 and 30?days. Growth, oxidative stress parameters [electrolyte leakage, peroxidation, and hydrogen peroxide (H₂O₂) concentration], antioxidant enzyme activities [ascorbate peroxidase (APX, EC 1.11.1.11), glutathione reductase (GR, EC 1.6.4.2), and peroxidases (POD, EC 1.11.1.7)], as well as antioxidant molecules [ascorbate and glutathione] were determined. The two salts affected leaf growth rates to the same extent, after 15 or 30?days of treatment, indicating a similar effect of Na₂SO₄ and NaCl salinity on growth, even if different (enzymatic and non-enzymatic) antioxidant mechanisms were involved in H₂O₂ detoxification. However, under both salts, the efficiency of the antioxidant metabolism seemed to be sufficient to avoid the deleterious effects of reactive oxygen species (ROS). Indeed, both ion leakage and peroxidation did not change under either Na₂SO₄ or NaCl salinity. As a whole, these data suggest that a cooperative process between the antioxidant systems is important for the tolerance of Ocimum basilicum L., cv. Fine to Na₂SO₄ and NaCl salinity.