Signaling Effects of Nitric Oxide, Salicylic Acid, and Reactive Oxygen Species on Isoeuphpekinensin Accumulation in Euphorbia pekinensis Suspension Cells Induced by an Endophytic Fungal Elicitor

Nitric oxide (NO), salicylic acid (SA), and reactive oxygen species (ROS) are important signal molecules that mediate plant resistance reactions and play important roles in secondary metabolism. To research the signal transduction pathway of the endophytic fungal elicitor from Fusarium sp. E5 promoting secondary metabolism in Euphorbia pekinensis suspension cells, the changes in NO, SA, ROS, and isoeuphpekinensin contents in the cells were investigated after elicitor addition to the cell suspension culture. The elicitor did not change H₂O₂ or O₂ ^? contents notably, whereas NO and SA contents were enhanced. Both the NO donator sodium nitroprusside (SNP) and SA enhanced isoeuphpekinensin content in the absence of the fungal elicitor, whereas the NO scavenger cPTIO and SA biosynthesis inhibitor cinnamic acid (CA) inhibited isoeuphpekinensin accumulation in the presence of the elicitor. In addition, cPTIO inhibited SA production induced by the fungal elicitor. CA did not inhibit NO production, but it significantly inhibited isoeuphpekinensin accumulation. The results demonstrated that in Euphorbia pekinensis suspension cells the endophytic fungal elicitor induced increased NO content and SA production, which promoted isoeuphpekinensin accumulation. ROS are clearly not involved in the endophytic fungus–host interaction signaling pathway.     

Photosynthetic Responses to Dynamic Light Environments by Hawaiian Trees : Time Course of CO(2) Uptake and Carbon Gain during Sunflecks

Gas exchange responses to rapid changes in light were studied in a C₃ tree, Claoxylon sandwicense Muell-Arg and a C₄ tree, Euphorbia forbesii Sherff that are native to the understory of a mesic Hawaiian forest. When light was increased to 500 micromoles per meter per second following a 2 hour preexposure at 22 micromoles per meter per second, net CO₂ uptake rates and stomatal conductance gradually increased for over 1 hour in C. sandwicense but reached maximum values within 30 minutes in E. forbesii. Calculation of the intercellular CO₂ pressures indicated that the primary limitation to CO₂ uptake during this induction was nonstomatal in both species. The photosynthetic response to simulated sunflecks (lightflecks) was strongly dependent on the induction state of the leaf. Total CO₂ uptake during a lightfleck was greater and the response was faster after exposure of the leaf to high light than when the leaf had been exposed only to low light for the previous 2 hours. During a series of lightflecks, induction resulted in increased CO₂ uptake in successive lightflecks. Significant postillumination CO₂ fixation was evident and contributed substantially to the total carbon gain, especially for lightflecks of 5 to 20 seconds' duration.     

Restoration of vegetation around mining enterprises

This paper is devoted to the restoration of vegetation around mining areas on the example of two land-reclamation zones in the Borodinsky coal mine during spring-summer of 2011–2021. Analysis of vegetation in this area has shown that indicators of spontaneous plant diversity in plots No. 1 and No. 2 were considered moderate in both layers (H < 2.5). Underwood and seeding diversity indices at pre-mining sites were ranked high, reaching 4.01–4.25 and 3.78–3.82, respectively. The analysis of the biological diversity of the flora in the undergrowth of the 12-year-old plot revealed approximately 29 spontaneous plant species belonging to 25 genera and 18 families. The most significant number of species found was found from the family Euphorbia, Cereals, and Legumes. At the 18-year-old site, the number and diversity of plant species (38 species) belonging to 38 genera and 27 families are slightly larger, with the most significant number of species within Euphorbiaceae and Poaceae, Asteraceae, Rubiaceae and Leguminosae. Saplings of various tree species from the Euphorbia and Leguminous family, such as Euphorbia cyparissias L., E. fischeriana Steud., Desmodium triflorum L., Indigofera gerardiana (Wall.) Baker, Robinia viscosa Vent. grew well in both plots. Many other spontaneous species of trees were also found in small populations at the 18-year-old site, namely, Pinus sylvestris L., Salix alba L., Populus alba L., and P. tremula L. In contrast to the younger site, some seedlings of small trees like S. alba and P. tremula and terrestrial ferns such as common bracken (Pteridium aquilinum (L.) Kuhn) and adiantum capillus-veneris L. prevailed in the older site.     

Purification and Characterization of Calmodulins from Papaver somniferum and Euphorbia lathyris

Calmodulins (CaM) were isolated and characterized from two well-known latex producing plants, Papaver somniferum and Euphorbia lathyris. The molecular weights of both were determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to be 17,000 comparable to that of bovine brain CaM. Amino acid compositions also compared similarly with those of known CaMs, with regard to the presence of trimethyllysine and the ratio of phenylalanine to tyrosine. The Cornish-Bowden equation (SΔn) revealed strong statistical correlations of P. somniferum and E. lathyris CaM with those of other plants and animals, although their amino acid compositions were not identical. Both plant CaM stimulated CaM dependent cAMP phosphodiesterase: for Papaver somniferum the K_a was found to be 1.09 nanomolar and for Euphorbia lathyris, 2.01 nanomolar.     

Comparison of the Oxygen Exchange between Photosynthetic Cell Suspensions and Detached Leaves of Euphorbia characias L

Using a mass-spectrometric ¹⁶O₂/¹⁸O₂-isotope technique, we compared the nature and the relative importance of oxygen exchange in photomixotrophic (PM) and photoautotrophic (PA) suspensions of Euphorbia characias L. with those in intact leaves of the same species. Young and mature leaves, dividing and nondividing cell suspensions were characterized in short-term experiments. On chlorophyll basis, the gross photosynthetic activities at CO₂ saturating concentration of PA and PM suspensions varied little from those of leaves. On dry weight basis, gross photosynthesis of PA suspensions was equal to that of leaves because of their similar chlorophyll content. This was not the case in PM suspensions where gross photosynthesis was lower and largely varied during the growth cycle. The CO₂ compensation point of PA cells (155-265 parts per million) was much higher than that of leaves (50-80 ppm). Oxygen uptakes were analyzed in terms of mitochondrial respiration, photorespiration and light stimulation of oxygen uptake (LSOU), often identified to Mehlertype reactions. In PA and PM suspensions, mitochondrial respiration rates were higher than in leaves by a factor of 1.5 to 4.5. In PM suspensions, photorespiration and LSOU were observed only in nondividing cells. Photorespiration and LSOU rates were comparable in PA suspensions and leaves. Our results demonstrate that photorespiration of PA suspensions has not been affected by the 2% CO₂ concentration imposed during 2 years of culture.     

NO inhibitory diterpenoids as potential anti-inflammatory agents from Euphorbia antiquorum

Two new ent-atisane-type diterpenoids (1 and 2), three new lathyrane-type diterpenoids (3–5), and seven known analogues (6–12) were isolated from Euphorbia antiquorum. The structures of these diterpenoids were established by analysis of their NMR, MS, and electronic circular dichroism data. The anti-inflammatory activities were evaluated biologically and compounds 1, 4, 7, 8, and 10 displayed strong NO inhibitory effects with IC₅₀ values less than 40 μM. The potential anti-inflammatory mechanism was also investigated using molecular docking and Western blotting.     

Triterpene Biosynthesis in the Latex of Euphorbia lathyris: Effect of Calmodulin Antagonists and Chlorinated Phenoxy Compounds

Recognized calmodulin antagonists and chlorinated phenoxyalkylamines were tested as inhibitors of mevalonate incorporation into triterpenols and their fatty acid esters in a centrifuged pellet from the latex of Euphorbia lathyris. The calmodulin antagonists, chlorpromazine (II), fluphenzine, and trifluoperazine were good inhibitors; I₅₀ values for II and trifluoperazine were 150 and 55 micromolar, respectively. Inhibition by the phenoxyalkylamines increased with increasing chlorine substitution, and I₅₀ for 2-(pentachlorophenoxy)ethyl N,N-diethylamine (IX) was 35 micromolar. The calmodulin-stimulated phosphodiesterase catalyzed hydrolysis of cAMP was used as an assay to quantitate the calmodulin antagonism of the tested compounds. Compounds II and IX were calmodulin antagonists over a concentration range similar to their effective range in the biosynthesis of triterpenes. The antagonism of the chlorinated phenoxy compounds increased in parallel to their inhibitory effect upon triterpene biosynthesis.     

Identification of maloyl glucans from Euphorbia tirucalli by ESI-(−)-FT-ICR MS analyses

Euphorbia tirucalli aerial parts are popularly used in Brazil for cancer treatment. The elution of the aqueous extract of the plant on silica gel C-18 cartridge furnished a water-soluble fraction, which was analyzed directly into the electrospray ionization (ESI) source combined with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) and characterized as a mixture of malic acid glycosides 1–5. The compounds were detected in their deprotonated form [M−H]⁻, where their exact mass (mass error lower than 1 ppm), molecular formula (C_nH_hO_o), double bond equivalent (DBE) and connectivity were determined from ESI-(−)-MS and ESI-(−)-MS/MS experiments. The presence of malic acid and glucose, as part of the structures, could originate from crassulacean acid metabolism (CAM) of the plant.     

Lathyrane type diterpene esters from Euphorbia lathyris

By reversed phase HPLC ‘ester L₇’, previously isolated among several macrocyclic lathyrol derivatives from seeds of Euphorbia lathyris, was     

Potential use in phytoremediation of three plant species growing on contaminated mine-tailing soils in Sardinia

We have analyzed the relationship between total Zn, Pb and Cu concentrations in the soil and the capacity of three plant species to accumulate these elements in their leaves. The study was carried out in a highly contaminated area at Sulcis-Iglesiente (SW-Sardinia, Italy). We took samples of the leaves of Dittrichia viscosa, Cistus salviifolius and Euphorbia pithyusa subsp. cupanii and samples of the soil beneath each of them at depths of 0-30 and 30-60 cm, both in contaminated mine tailings and surrounding areas. Due to the anthropic origin of the soil materials the results varied considerably. Bioavailability of trace elements was mainly related to the calcium-carbonate content and the crystalline and amorphous forms of iron in the soil. The concentration of Zn in the leaves of the three plant species studied was highest, followed by Pb and finally Cu. The leaves of Dittrichia viscosa contained the highest concentrations of trace elements and this species may be considered as being a “phytoextractor” in soils where the trace-element concentrations are not too high. Euphorbia pithyusa subsp. cupanii had low trace-element concentrations in its leaves despite growing in highly contaminated soils, and so might be used as a “phytostabilizer”. Although Cistus salviifolius does not grow in the most contaminated soils, could be considered as a contamination indicator up to a given level.     

Enhancement of Terpenoid Biosynthesis from Mevalonate in a Fraction of the Latex from Euphorbia lathyris

A latex pellet fraction from Euphorbia lathyris incorporates mevalonate into triterpenols and their fatty acid esters. Conditions for improved incorporation were determined. CaCl₂ or CaCl₂ plus MnCl₂ stimulated biosynthesis, and the metal ion chelator, ethylenebis(oxyethylenenitrilo)tetraacetic acid (EGTA) enhanced stimulation. Ethylenediaminetetraacetic acid was almost as effective as EGTA, but phthalic acid and citric acid were relatively poor stimulators. The concentration of the Ca²⁺-EGTA complex was directly measured, and the incorporation data are best fitted by a curve that shows that the receptor for the complex is saturable. In the presence of the metal-chelate complex, the addition of fructose, 1,6-bisphosphate plus aldolase (triose-P) or malate provided additional stimulation. Incorporation was maximum at 40 micromolar R-mevalonate, and inhibition occurred at higher concentrations. The apparent K_m for R-mevalonate was 15 micromolar. Under improved reaction conditions, the rate of triterpenoid biosynthesis from mevalonate is 25 times faster than was previously observed (GJ Piazza, EJ Saggese, KM Spletzer [1987] Plant Physiol 83: 177-180).     

Three serine proteases from the latex of Euphorbia cyparissias

Three serine-centred proteolytic enzymes, euphorbains y-1, ?2 and ?3, were isolated from the latex of Euphorbia cyparissias. These proteases have different specific activities to azocoll and CBZ glycine p-nitrophenyl ester. The pIs and M_rs of y-1, ?2 and ?3 are 5.2 and 67 000, 5.2 and 33 000, and 6.3 and 67 000, respectively. The enzymes, which are glycoproteins, are immunologically distinct from euphorbain 1, but clearly related to that enzyme in amino acid composition.     

Leaf phenology and water potential of five arboreal species in gallery and montane forests in the Chapada Diamantina; Bahia; Brazil

The influence of water potential (Ψ_W) on the leaf phenological behaviors of five arboreal species within gallery and montane forests on the eastern slope of the Chapada Diamantina Mountain Range in Bahia State, NE Brazil, was examined to investigate the following questions: (1) Do seasonal variations in rainfall influence the water potential of these species in their natural habitats (gallery and montane forests)? (2) Do the gallery forest species show smaller daily variations in their water potential and greater nocturnal recuperation than montane species? (3) Can the water potentials of these species be used to identify their particular types of leaf phenologies? The species examined were Tibouchina fissinervia and Clusia nemorosa (evergreen with continual leafdrop); Tapirira guianensis and Vochysia pyramidalis (evergreen with concentrated leafdrop), and Maprounea guianensis (brevi-deciduous) were chosen based on their abundance, importance value indices, and contrasting phenological behaviors. The leaf phenologies of all species were similar in both forest types. Evergreen species with continual leafdrop demonstrated leaf budding and leaf fall occurred at low levels during the entire year. Evergreen species with continual leafdrop as well as brevi-deciduous species demonstrated peaks of leaf fall and leaf budding during the dry period. Brevi-deciduous trees remained without leaves for an average of three days. The major episodes of leaf budding occurred during the dry period in all of the species examined. M. guianensis usually demonstrated low predawn (Ψ_PD) and midday (Ψ_MD) water potentials (Ψ_W). C. nemorosa demonstrated the greatest Ψ_PD and Ψ_MD values and the lowest daily amplitude (Δ_Ψ), suggesting that this plant used CAM during most of the study period. The majority of the species demonstrated small seasonal differences in Ψ_W, and the Ψ_PD values indicated a satisfactory nocturnal recuperation of their water status, even during the dry period. The maximum daily amplitude of Ψ_W was observed in V. pyramidalis, a species dependent on moist habitats for establishment and growth. No large decrease in Ψ_PD was observed during the study period in the species examined here, and all species demonstrated leaf budding during the dry period, suggesting that there were no severe water restrictions in either the gallery or montane forests. However, during dry periods, the species generally demonstrated lower Δ_Ψ. This reflects the restriction of transpiration, which according to phenological data, may occur due to different mechanisms, depending on the species. Our data supports the view that there is no strict relationship between decreasing water status in these plants and leaf fall.     

Hybridization and introgression between the exotic Siberian elm, Ulmus pumila, and the native Field elm, U. minor, in Italy

In response to the first Dutch elm disease (DED) pandemic, Siberian elm, Ulmus pumila, was planted to replace the native elm, U. minor, in Italy. The potential for hybridization between these two species is high and repeated hybridization could result in the genetic swamping of the native species and facilitate the evolution of invasiveness in the introduced species. We used genetic markers to examine the extent of hybridization between these two species and to determine the pattern of introgression. We quantified and compared the level of genetic diversity between the hybrids and the two parental species. Hybrids between U. pumila and U. minor were common. The pattern of introgression was not as strongly biased towards U. pumila as was previously observed for hybrids between U. rubra and U. pumila in the United States. The levels of heterozygosity were similar between U. minor and the hybrids and both groups had higher levels of heterozygosity relative to U. pumila. The programs Structure and NewHybrids indicated the presence of first- (F₁) and second- generation (F₂) hybrids and of backcrosses in the hybrid population. The presence of healthy DED resistant U. minor individuals combined with the self-compatibility of U. minor could help explain the presence of F₂ individuals in Italy. The presence of F₂ individuals, where most of the variability present in the hybrids will be released, could facilitate rapid evolution and the potential evolution of invasiveness of U. pumila in Italy.     

New jatrophane diterpenes from Euphorbia osyridea with proapoptotic effects on ovarian cancer cells

A dichloromethane–acetone extract of Euphorbia osyridea Bioss. (Syn. Euphorbia lateriflora Schumach. & Thonn), a spurge endemic to Iran and West Africa, afforded three new jatrophane diterpenes belonging to the 2,3,5,7,8,9,14,15-octahydroxy-jatropha-6(17),11E-diene class along with three known triterpenes. Structures of these compounds were elucidated by spectroscopic methods, especially 2D NMR analyses. Biological effects of these compounds were analyzed by performing MTT and annexin V-FITC and PI staining assays against different cancer cell lines. Results showed that 2,3,5,7,8,9,14,15-octahydroxy-jatropha-6(17), 11E-diene derivatives (1–3) inhibit the cell proliferation through apoptosis in the Caov-4 and OVCAR-3 cancer cell lines.     

Phorbic Acid biosynthesis in the latex vessel system of euphorbia

Evidence is presented that phorbic acid is formed in the latex producing cell system, rather than in photosynthetic or chlorophyll-free tissues of Euphorbia resinifera Berg. When a branch of the plant was kept first in a ¹⁴CO₂ atmosphere with 12 hr light-dark periods for 2 days and then left under natural conditions in the air outside for at least 2 to 3 days, radioactive phorbic acid was found in the latex. Phorbic acid synthesis appeared to be independent of the photosynthetic and respiratory activities of the plant.     

Acid phosphatases from latices of euphorbiaceae

Five phosphatases were isolated from the latices of three members of the Euphorbiaceae. From Euphorbia lathyris were obtained phosphatases 1₁ and 1₂; from E. trigona phosphatase t and from Elaeophorbia drupifera the enzymes d₁ and d₂. Phosphatases 1₁, 1₂ and t were purified to homogeneity. Amino acid compositions are reported and other properties of the enzymes are described. The two enzymes described from E. lathyris both have two pH maxima d(1₁ at 5.0 and 6.8,1₂ at 5.8 and 7.5) while t, d₁ and d₂ respectively have maxima at pHs of 5.6,5.6 and 5.0. On the basis of their responses to several residue-specific inhibitors the five phosphatases apparently comprise three groups: 1₂ and d₁, t and d₂, and 1₁.     

Hydrocarbon-and rubber-producing crops

Agricultural production of rubber and other hydrocarbons in the United States may be compatible with increased food and fiber production if entire plants are harvested and processed for fiber, protein, and carbohydrate as well. Thus, procedures and criteria have been established for the preliminary evaluation of plant species as potential multi-use hydrocarbon-producing crops. Previously, 106 species representing 44 families and 81 genera were evaluated. Now an additional 100 species representing 13 additional families and 60 additional genera have been evaluated, and some of these species also offer promise as future crops. Several Labiatae are high in natural rubber (NR) content;Pycnanthemum incanum (Mountain Mint) andTeucrium canadense (American Germander) were evaluated as promising species. Three Compositae,Cacalia atriplicifolia (Pale Indian-Plant),Solidago graminifolia (Grass-leafed Golden-rod), andSolidago rigida (Stiff Goldenrod) were also evaluated as promising species for NR.Campanula americana (Tall Bellflower, Campanulaceae) has potential as a source of both oil and NR.Euphorbia dentata (Euphorbiaceae ) does not produce NR but is very high in protein and oil contents.Sassafras albidum (Sassafras, Lauraceae ) is of interest for its rapid growth rate in combination with a high oil content. A few other species offer some promise.     

Variations in leaf respiration across different seasons for Mediterranean evergreen species

Leaf respiration (R _L) of evergreen species co-occurring in the Mediterranean maquis developing along the Latium coast was analyzed. The results on the whole showed that the considered evergreen species had the same R _L trend during the year, with the lowest rates [0.83 ± 0.43 μmol(CO₂) m^?2 s^?1, mean value of the considered species] in winter, in response to low air temperatures. Higher R _L were reached in spring [2.44 ± 1.00 μmol(CO₂) m^?2 s^?1, mean value] during the favorable period, and in summer [3.17 ± 0.89 μmol(CO₂) m^?2 s^?1] during drought. The results of the regression analysis showed that 42% of R _L variations depended on mean air temperature and 13% on total monthly rainfall. Among the considered species, C. incanus, was characterized by the highest R _L in drought [4.93 ± 0.27 μmol(CO₂) m^?2 s^?1], low leaf water potential at predawn (Ψ_pd= ?1.08 ± 0.18 MPa) and midday (Ψ_md = ?2.75 ± 0.11 MPa) and low relative water content at predawn (RWC_pd = 80.5 ± 3.4%) and midday (RWC_md = 67.1 ± 4.6%). Compared to C. incanus, the sclerophyllous species (Q. ilex, P. latifolia, P. lentiscus, A. unedo) and the liana (S. aspera), had lower R _L [2.72 ± 0.66 μmol(CO₂) m^?2 s^?1, mean value of the considered species], higher RWC_pd (91.8 ± 1.8%), RWC_md (82.4 ± 3.2%), Ψ_pd (?0.65 ± 0.28 MPa) and Ψ_md (?2.85 ± 1.20 MPa) in drought. The narrow-leaved species (E. multiflora, R. officinalis, and E. arborea) were in the middle. The coefficients, proportional to the respiration increase for each 10°C rise (Q₁₀), ranging from 1.49 (E. arborea) to 1.98 (A. unedo) were indicative of the different sensitivities of the considered species to air temperature variation.