Pyrethrum Research Articles

High diversity of natural Dalmatian pyrethrum based on pyrethrin composition at intra- and interpopulation level

Seeds collected from 10 Dalmatian pyrethrum (Tanacetum cinerariifolium /Trevir./ Sch. Bip. Asteraceae) populations naturally occurring along the Adriatic coast and islands, were used to establish a common garden with the aim of estimating the variation of pyrethrin compounds between and within populations. A recently optimized matrix solid phase dispersion (MSPD) method was used for the extraction of six pyrethrin compounds from dry flower heads of 200 Dalmatian pyrethrum individuals. Separation and quantification of pyrethrin compounds were performed by high performance liquid chromatography with diode array detector (HPLC-DAD). High variability in pyrethrin content and composition was observed within and between populations. Total pyrethrin content in individual samples varied from 0.10% to 1.35% of flower dry weight. On average, the lowest total pyrethrin content was observed in the population of Pelješac (0.22%) and the highest in the island populations of Mali Lošinj and Zlarin (0.87%). The population of Mali Lošinj had the most favourable pyrethrin profile, including the lowest variability in total pyrethrin content, the highest pyrethrin I (PI) content (up to 60.47%) and PI/PII ratio (up to 5.88), as well as the lowest pyrethrin II (PII) content. In contrast, the populations from Biokovo and Pelješac represented pyrethrin profiles with the lowest content of total pyrethrin, PI and PI/PII ratio. The Biokovo population also had the highest PII content (43.18% on average), while the Pelješac population had the highest jasmolin I (JI) and jasmolin II (JII) content. Four different chemotypes were determined by cluster analysis. Chemotype P1 is the most promising for future breeding programs and is characterized by the highest total pyrethrin content, PI content and PI/PII ratio, as important measures of insecticidal activity. Correlation analysis of each pyrethrin compound with 25 environmental variables and Principal Component Analysis (PCA) were carried out and the importance of optimum temperature and precipitation on pyrethrin quantity and quality was suggested. Total pyrethrin content was significantly correlated with six temperature and five precipitation parameters. Pyrethrin I, PII and cinerin II (CII) were significantly correlated mainly with temperature parameters; JII and cinerin I (CI) with precipitation parameters, while JI was correlated with temperature range and precipitation parameters. The mountainous Biokovo population was an outlier in the PCA analysis, mainly due to the extremely low values of temperature parameters at a higher altitude. Precipitation variables separated the central Adriatic islands inhabiting drier habitats from populations inhabiting habitats with greater precipitation. The high-resolution data from this study provide the opportunity for individual-based selection for breeding plants with the best pyrethrin profiles, as well as for increased adaptation to broader climatic conditions.

Identification of multiple odorant receptors essential for pyrethrum repellency in Drosophila melanogaster.

Pyrethrum extract from dry flowers of Tanacetum cinerariifolium (formally Chrysanthemum cinerariifolium) has been used globally as a popular insect repellent against arthropod pests for thousands of years. However, the mechanistic basis of pyrethrum repellency remains unknown. In this study, we found that pyrethrum spatially repels and activates olfactory responses in Drosophila melanogaster, a genetically tractable model insect, and the closely-related D. suzukii which is a serious invasive fruit crop pest. The discovery of spatial pyrethrum repellency and olfactory response to pyrethrum in D. melanogaster facilitated our identification of four odorant receptors, Or7a, Or42b, Or59b and Or98a that are responsive to pyrethrum. Further analysis showed that the first three Ors are activated by pyrethrins, the major insecticidal components in pyrethrum, whereas Or98a is activated by (E)-β-farnesene (EBF), a sesquiterpene and a minor component in pyrethrum. Importantly, knockout of Or7a, Or59b or Or98a individually abolished fly avoidance to pyrethrum, while knockout of Or42b had no effect, demonstrating that simultaneous activation of Or7a, Or59b and Or98a is required for pyrethrum repellency in D. melanogaster. Our study provides insights into the molecular basis of repellency of one of the most ancient and globally used insect repellents. Identification of pyrethrum-responsive Ors opens the door to develop new synthetic insect repellent mixtures that are highly effective and broad-spectrum.

Herb and conifer roots show similar high sensitivity to water deficit.

Root systems play a major role in supplying the canopy with water, enabling photosynthesis and growth. Yet, much of the dynamic response of root hydraulics and its influence on gas exchange during soil drying and recovery remains uncertain. We examined the decline and recovery of the whole root hydraulic conductance (Kr) and canopy diffusive conductance (gc) during exposure to moderate water stress in two species with contrasting root systems: Tanacetum cinerariifolium (herbaceous Asteraceae) and Callitris rhomboidea (woody conifer). Optical dendrometers were used to record stem water potential at high temporal resolution and enabled non-invasive measurements of Kr calculated from the rapid relaxation kinetics of water potential in hydrating roots. We observed parallel declines in Kr and gc to <20% of unstressed levels during the early stages of water stress in both species. The recovery of Kr after rewatering differed between species. T. cinerariifolium recovered quickly, with 60% of Kr recovered within 2 h, while C. rhomboidea was much slower to return to its original Kr. Recovery of gc followed a similar trend to Kr in both species, with C. rhomboidea slower to recover. Our findings suggest that the pronounced sensitivity of Kr to drought is a common feature among different plant species, but recovery may vary depending on root type and water stress severity. Kr dynamics are proposed to modulate gc response during and following drought.

Tissue specificity of (E)-β-farnesene and germacrene D accumulation in pyrethrum flowers

Plant defensive mimicry based on the aphid alarm pheromone (E)-β-farnesene (EβF) was previously shown to operate in Tanacetum cinerariifolium (Asteraceae) flowers. Germacrene D (GD), is another dominant volatile of T. cinerariifolium flowers and may modulate both defense and pollination. Here, we find that the increase in GD/EβF ratio at later developmental stages is correlated with the tissue distribution in the flower head: the total content of EβF and GD is similar, but GD accumulates comparatively more in the upper disk florets. Naphthol and N, N-dimethyl-p-phenylenediamine dihydrochloride (NADI)-stained purple ducts containing EβF and GD, were observed in the five petal lips of the corolla and two-lobed stigma of disk florets. By contrast in the peduncle, EβF accounts for nearly 80% of total terpenes, compared to 5% for GD. EβF is accumulated inside inner cortex cells and parenchyma cells of the pith in young peduncle. This is followed by the formation of terpene-filled axial secretory cavities parallel to the vascular bundles. In conclusion, the observed developmental and diurnal emissions of different EβF/GD ratios appear to be regulated by their tissue distribution.

Rapid generation cycling transforms pyrethrum (Chrysanthemum cinerariifolium) into an annualized perennial

AbstractPyrethrum [Chrysanthemum cinerariifolium (Trevir.) Vis.] is an important “green pesticide” crop widely used for insect control on plants and for humans. Pyrethrum flowers have the highest Pyrethrin I/Pyrethrin II ratio (%Py) and are harvested at specific stages to maximize yield. Selection for correlative early seed germination and flowering in first year pyrethrum seedlings is challenging and has not been accomplished previously. The breeding objectives for this study were to sample a wide germplasm base to select for rapid generation cycling (RGC) traits of early and high germination in Weeks 1–4, earliness of visible bud date (VBD) and flowering, accelerated growth, high leaf unfolding rates per week, number of shoots, and %Py in the 1st–12th flowers. Seven seed lots were evaluated for germination rate and timing (N = 141,120 seeds) in Year 1 for RGC traits. Seedling germination was recorded weekly with toothpicking to identify germination weeks with successive selection occurring at transplanting. Grand mean percentage germination was low (24.5%), whereas individual seed lots varied (18.4–38.9%). Seedling death was 0.0–6.8%. On average, it took 34–39 wk to reach VBD and an additional 3–4 wk to flower. Thus, flowering in &lt;1 yr without vernalization is a new trait (annualized perennial) selected in this crop. Germination week was significantly correlated with VBD and flowering dates and is an important trait to use for selecting early‐flowering genotypes in plug trays. Pyrethrum breeding programs could select the earliest germinating seedlings (Weeks 1–4 after sowing) at transplanting to enhance the likelihood of selecting early‐flowering genotypes in the first year and provide an additional year of harvest to increase yield.

Future and Prospect use of Pyrethrum (Chrysanthemum cinerariifolium) as Part of the Integrated Pest and Disease Management (IPDM) Tool in Turkey

Nowadays, immediate environmental friendly solutions such as the use of biopesticides and other methods to control and manage pests are well needed. They are imperative due to the continuous accumulation of toxic residues from synthetic insecticides into the environment, the contamination of global agro-ecosystem and resistance of certain insects and pathogens. The global renewed interest of botanical pesticides does not leave aside Turkey. Thus, many environmental reports pointed out contaminations in different regions of Turkey by chemical pesticide residues, like lambda-cyhalothrin in some conventional grapes farming in the Aegean region. The use of botanical pesticides like Pyrethrin extracted from Pyrethrum‘s flowers (Chrysanthemum cinerariifolium) is part of sustainable agriculture goals to reduce the incidence of pests and diseases without any alteration to the natural balance. The purpose of this review is to analyse and identify the possibilities of Pyrethrum production in Turkey. Various research works around the world were compiled and some key informants were correlated to existing researches in Turkey. Subsequently, it was found that the Black-Sea region of Turkey has great potential in the growing and industrial production of Pyrethrum by its weather patterns (temperatures, pluviometry and humidity) and soil characteristics. The region has a similar climate with the East-African high-lands well-known for Pyrethrum production. Thus, the country has shown great technological advances and the capacity to produce vegetative and disease-free clones for other ornamental plants by using tissue culture techniques. Therefore, the multiplication of high-quality vegetative clones of Chrysanthemum cinerariifolium and their maintenance can sustain commercial and long term production of Pyrethrum in Turkey.

Genetic improvement of pyrethrum (Tanacetum cinerariifolium Sch. Bip.) through gamma radiation and selection of high yield stable mutants through seven post-radiation generations

Purpose To increase the size of the flowers for easy plucking, flower yield, pyrethrins content (%), and elite mutant selection in pyrethrum. Materials and methods To increase pyrethrum production and acclimatize in north Indian plain condition, a genetic improvement program was undertaken to widen the range of variations for size and yield of flowers and pyrethrins content (%) in pyrethrum crop. Pyrethrum seeds of the variety Avadh were irradiated with gamma rays at 20 to 300 Gy doses in Gamma chamber 5000 (cobalt-60 research irradiator). Results Observations gathered visually in M1 based on vigor, synchronization of flowering, and flower’s size. Out of 90 M2 families, 20 mutants were raised in M3 along with the check-in preliminary evaluation trial. The four promising mutants, 1 (20 Gy-3), 7 (40 Gy-5), 10 (40 Gy-8), 14 (60 Gy19-10) was grown for four years in a bench-scale trial (randomized block design, replicated thrice) to test the yield performance and selection of high yielding elite mutant (s). It has been found that pyrethrum is sensitive to gamma rays irradiation and produced a high range of qualitative and quantitative variations. After massive screening over four years, two promising mutants for high dry flower yield and pyrethrins content, namely 7 (40 Gy-5), and 10 (40GY-8) were isolated. Conclusions The mutagenesis changed traits mean in positive or negative directions. Pyrethrum plant is highly sensitive to gamma irradiation and produced a high range of variability in the qualitative and quantitative traits. The mutagenesis changed the mean of traits in both positive and negative directions. Due to mutagenic efficacy, two mutants 7 (40 Gy-5), and 10 (40GY-8) were expressed high performance for pyrethrin percent i.e., 87.23 and 59.78% improvement over the check variety ‘Avadh’, with synchronous flowering. These two mutants are in the pipeline for release as a variety for cultivation in the North Indian plains.

Sequences Analysis Of The Candidate Genes Involved In Artemisinin Biosynthetic Pathway in Artemisia annua plant

Artemisia annua is a medicinal plant that produce artemisinin, which has antimalarial activity. Artemisinin biosynthesis pathway depends on number of genes such as ADS, CPR and CYP71AV1. we studied gene structure of three genes which exhibit ADS gene possess 4 introns and 5 Exons with length 1794bp, CPR has to analyze the sequences of these genes, the CPR gene contains 6 introns and 7 exons with length 1633bp and CYP71AV1gene has 1 intron and 2 Exons with length 1554bp. Cis-acting elements detection in ADS, CPR and CYP71AV1 promoters revealed several such W-box , WRKY , TATA-BOX,CAAT-BOX ,IBOX MYC ,EBOX,GATA-BOX, which could be involved in gene expression regulation of artemisinin production genes. Our genes could be influenced by different external affects as light, cold, drought and elicitors which in turn may be due to an effect on the amount of artemisinin produced. ADS, CPR and CYP71AV1 proteins evolution shows Artemisia annua, and Tanacetum cinerariifolium always are closed in one cluster which refers to a common ancestor of those two genotypes.

Reduction Chemistry of Natural Pyrethrins and Preliminary Insecticidal Activity of Reduced Pyrethrins

The natural extract pyrethrum is an insecticidal oil derived from Tanacetum cinerariifolium that is commonly used in domestic and agricultural pesticides. The major constituents of the extract are the Pyrethrins, six esters that provide pyrethrum with its insecticidal properties. These Pyrethrins readily degrade through several environmental means and as such, there can be significant Pyrethrin losses during processing and long-term storage of pyrethrum-based insecticides. This work attempts to alleviate the effect of these degradative processes through the pursuit of stabilised Pyrethrins by chemically removing oxidatively sensitive functionality. Several reduced Pyrethrin analogues were produced and a method to convert the more sensitive Pyrethrins present in the pyrethrum concentrate into their respective more stable jasmolin counterparts, as a mixture with the over-reduced tetrahydropyrethrins, was developed. All other reduction processes abolished insecticidal activity against Lucilia cuprina larvae, whereas some isomerised analogues showed comparable potency with the individual natural pyrethrin esters. This work has revealed new insights into the structure–activity relationships in this unique class of insecticide.

Endophytic fungi for biological control of whitefly and tomato leaf miner in Tanzania

Tomato whiteflies (Bemisia tabaci) and leaf miners (Tuta absoluta) are devastating pests of tomato (Lycopersicon esculentum). Pest management using broad spectrum synthetic pesticides is discouraged due to harmful effects on human health and the environment. The objective of this study was to assess the potential of endophytic fungi as bioextracts against tomato whiteflies and leaf miners, as an alternative to synthetic insecticides in Tanzania. The study was done using morphological and molecular techniques, during January 2019 to February 2020 in Arusha region in Tanzania. Three endophyte isolates from pyrethrum (Chrysanthemum cinerariifolium) and lemon grass (Cymbopogon citratus) were identified with resemblance to members of Fusarium sp and Altenaria sp, by 90 and 82 % similarity, respectively; based on phylogenetic clustering patterns and macro- and micro-morphological characteristics. Bioextracts from endophytes of lemon grass leaves (Elg1); and pyrethrum flowers (Epf1) and leaves (Epl1), showed significant repellency properties (F0.05 (df, 15) = 27.052, P = 0.0001) on whiteflies by 54, 76 and 36%, respectively. They also caused significant lethality (F0.05 (df, 11) = 59.559, P = 0.0001) of tomato leaf miner larvae and whiteflies (F0.05 (df, 11) = 53.600, P = 0.0001). The underlying effect was attributed to possession of flavonoid and total phenolics as active ingredients in the bioextracts. This was commensurate to the levels flavonoid and total phenolic contents, which were considerably more in bioextracts of lemon grass and pyrethrum flower (F0.05 (df, 8) = 10.35, P = 0.0114) and (F0.05 (df, 8) = 40.84, P = 0.0003, respectively), than in pyrethrum leaves.

Study in Silico Compounds In 96% Ethanol Extract of Chrysanthemum cinerariifolium (Trev.) Leaves Towards Alfa Estrogen Receptors

Chrysanthemum cinerariifolium (Trev.) is a plant that has potential as an anticancer. This study aimed to predict the inhibitor of estrogen alpha and toxicity of compounds in 96% ethanol extract of C. cinerariifolium leaves in silico. Prediction of the activity of metabolic profiling compounds produced by UPLC QToF MS/MS ethanol extract 96% of C. cinerariifolium leaves towards alpha estrogen receptors (ER-α) (5W9C) was carried out using Molegro Virtual Docker. The docking results showed that the compound (2-Methyl-1,4-piperazinediyl) bis-[(3,4,5-trimethoxyphenyl)-methanone and Azoxystrobin have good activity compared to Tamoxifen, because these compounds have a lower Rerank Score. The activity of the test compound is also shown by the bonding of active amino acids (Arg 394, Asp351, Glu 353, and Val 533). As for the toxicity class based on Globally Harmonized System (GHS) and Lethal Dose 50 (LD50) values, the ten docking compounds had a relatively low toxicity.Keywords: C. cinerariifolium, breast cancer, alpha estrogen, cytotoxic activity, toxicity

Pyrethrin from Dalmatian pyrethrum (Tanacetum cinerariifolium (Trevir.) Sch. Bip.): biosynthesis, biological activity, methods of extraction and determination

Pyrethrin is a potent biopesticide, a natural mixture of six compounds (pyrethrin I and II, cinerin I and II, and jasmolin I and II), biosynthesized in plants of Dalmatian pyrethrum (Tanacetum cinerariifolium/Trevir./Sch. Bip.), a species endemic to the eastern Adriatic coast, but grown worldwide. Not many known natural insecticides encompass such superior qualities as pyrethrin—very high efficacy against a broad spectrum of pests in combination with minor adverse effects on human health and the environment. In previous decades, pyrethrin was largely replaced by its synthetic derivatives, pyrethroids. However, due to their harmful effects on various species and ecosystems, the use of pyrethrin should again take the lead. This review summarizes one century (1920–2020) of research on the properties and use of pyrethrum as a source of pyrethrins. The primary focus is on presenting its current advantages and disadvantages, toxicity on target and non-target species, biosynthesis, factors that influence the pyrethrins content in pyrethrum, comparison of different methods of their extraction and determination; as well as its production potential and development of new products. The final goal is to present possible approaches to improve and enhance the use of this highly effective but still underused phytochemical insecticide with unique properties.

PENGAMBANGAN SISTEM NANOSTRUCTURED LIPID CARRIER (NLC) DAUN Chrysanthemum cinerariifolium (Trev.) Vis DENGAN VARIASI KONSENTRASI LIPID

Ethanol extract 96% of Chrysanthemum cinerariifolium (Trev.) Vis leaves are proven to have anticancer activity. However, these compounds have low solubility in water and fat. To improve the bioavailability of preparations, the development of drug design in the form of Nanostructured Lipid Carrier (NLC) is carried out.The aim this study was to determine the effect of differences in lipid concentration of Monostearin and Oleic Acid in the formulation of the NLC system of Chrysanthemum cinerariifolium (Trev.) Vis leaves, which produced good physicochemical characteristics including organoleptic characteristics, pH, viscosity, particle size, and drug entrapment efficiency. Making is done using the High Shear Homogenization method. Organoleptic tests showed ideal results for the Nanostructured Lipid Carrier (NLC) system, the resulting pH values in formula 1 (7.0 ± 0.12), formula 2 (6.7 ± 0.17) and formula 3 (6.8 ± 0.2)), the viscosity value of formula 1 (55.66 ± 2.84 cPs), formula 2 (28.86 ± 3.91 cPs), and formula 3 (28.57 ± 16.85 cPs). Particle size of formula 1 (5530 ± 320.47 nm), formula 2 (5337 ± 671.44 nm) and formula 3 (4676 ± 2215.75 nm)). The entrapment efficiency value of formula 1 drugs (33.55%), formula 2 (38.77%), formula 3 (83.75%). Based on the characterization result, the best formula was obtained at a lipid concentration of 10%, which was used for the formula of the NLC system of Chrysanthemum cinerariifolium (Trev.) Vis leaves for oral anticancer preparations

How Plants Synthesize Pyrethrins: Safe and Biodegradable Insecticides.

Natural pyrethrin insecticides produced by Dalmatian pyrethrum (Tanacetum cinerariifolium) have low mammalian toxicity and short environmental persistence, providing an alternative to widely used synthetic agricultural insecticides that pose a threat to human health and the environment. A recent surge of interest in the use of pyrethrins as agricultural insecticides coincides with the discovery of several new genes in the pyrethrin biosynthetic pathway. Elucidation of this pathway facilitates efforts to breed improved pyrethrum varieties and to engineer plants with improved endogenous defenses or hosts for heterologous pyrethrin production. We describe the current state of knowledge related to global pyrethrum production, the pyrethrin biosynthetic pathway and its regulation, and recent efforts to engineer the pyrethrin pathway in diverse plant hosts.

The complete chloroplast genome of Tanacetum coccineum

Tanacetum coccineum, a perennial plant of the Tanacetum genus, cultivated as a natural pesticide or ornamental plant widely distributed in many countries. In this research, the complete chloroplast genome sequence of T. coccineum was determined to comprise a 150,143 bp double-stranded circular DNA, including a pair of 24,416 bp inverted repeat regions (IRs), small single copy (SSC) region of 18,389 bp and large single copy (LCS) region of 82,922 bp. An overall GC content was 37.49%, and the corresponding values in IRs, SSC, and LSC regions are 43.16%, 30.88%, and 35.61%, respectively. A total of 129 genes include 84 protein-coding genes, 37 tRNA, and eight rRNA. Four rRNA genes and seven tRNA genes were duplicated in IRs. A phylogenetic tree reconstructed by 38 Composite family chloroplast genomes sequence reveals that T. coccineum is mostly related to Ismelia carinata.

Pyrethrum (Chrysanthemum cinerariifolium) Flowers’ Drying Conditions for Optimum Extractable Pyrethrins Content

Pyrethrum flowers of the genus Chrysanthemum cinerariifolium are grown in Kenya by small scale farmers for extraction of pyrethrins, a natural insecticide&amp;rsquo;s active ingredient. Pyrethrins are classified in two groups, Pyrethrins I and II, and are degradable when exposed to air, moisture and high temperatures. The contents and ratio of Pyrethrins I:II determine the efficacy of the insecticide. Therefore, drying of the pyrethrum flowers should be optimized in order to attain maximum extractable pyrethrins content and optimum ratio. The aim of this research was to optimize the drying temperatures, time and moisture content of pyrethrum flowers. The flowers were harvested and dried at varying temperatures of 40, 50, 60 and 70 &amp;ordm;C to total dryness. Another set of flowers were harvested and dried in the oven at the same temperatures for a maximum period of 18 hrs. Moisture content was determined at each temperature, at intervals of one hour. The dried flowers were then ground into fine powder and extracted using Soxhlet extraction method with hexane. The extracts were refined and analyzed by Mercury reduction and High Performance Liquid Chromatographic methods. Pyrethrum flowers were found to achieve maximum moisture loss, at varying times and temperature with 70 &amp;ordm;C recording the shortest time of 18 hrs. The yield of pyrethrins obtained on drying the flowers to constant weight at 40 &amp;ordm;C was 0.90% while drying for 18 hrs yielded 0.79%. Extractable Pyrethrins II were found to reduce by 8.6% when the drying temperature was raised from 50 to 60 &amp;ordm;C and by 11.3% from 60 to 70 &amp;ordm;C. Extractable Pyrethrins I were found to reduce by 6% when the drying temperature was raised from 50 to 60 &amp;ordm;C and by 5% from 60 to 70 &amp;ordm;C. The total pyrethrins obtained from the flowers dried at 50 &amp;ordm;C were found to be 1.37% at 18 hrs and 1.44% to constant weight drying. The pyrethrins I:II ratio was found to vary over the temperature range 40-70OC.The optimum temperature and time for drying pyrethrum flowers was found to be 50 &amp;ordm;C for 21 hrs.

Exposure to heat stress during flowering period reduces flower yield and pyrethrins in Pyrethrum (Tanacetum cinerariifolium)

AbstractHeat stress is one of the major limitations to crop productivity worldwide. Global warming effects are expected to increase the number of hot days and increase the probability and intensity of heat stress events. Short periods (3–5 days) of heat stress with maximum temperatures exceeding 35°C often occur during late spring and early summer in some pyrethrum growing regions of Australia. These heat stress events usually coincide with pyrethrum flowering period. Pyrethrum is a perennial herbaceous plant which is commercially grown for extraction of pyrethrins which accumulate in the achenes of the flowers and are used as a natural insecticide. This experiment was conducted to understand the effects of timing of short periods of heat stress on flower development and pyrethrum yield. Plants were subjected to short periods of high temperature treatments (12 hr at 35–40°C) for three consecutive days at three flower maturity stages (early, mid, late). Control plants were grown at ambient temperature (10–25°C) throughout the flowering period. Exposure of pyrethrum plants to short periods of high temperature during the flowering period caused a significant reduction in the flower and pyrethrin yield. This was associated with the reduction in flower size and accelerated flower senescence. Exposure of pyrethrum plants to heat stress significantly increased the rate of flower development resulting in a shorter flowering period. Overall, plants grown under control treatment showed slower rate of flower development and longer duration flowering period. This resulted in longer duration of pyrethrin accumulation and higher yield of pyrethrins per flower. Timing and duration of heat stress significantly influenced pyrethrin yield per flower. Heat stress caused more severe yield reductions at early flowering than later in the flowering period. Research focusing on agronomic strategies, phenology and breeding for tolerance to heat stress is therefore important to cope with future climate changes and to obtain maximum pyrethrin yield.

A Trichome-Specific, Plastid-Localized Tanacetum cinerariifolium Nudix Protein Hydrolyzes the Natural Pyrethrin Pesticide Biosynthetic Intermediate trans-Chrysanthemyl Diphosphate.

Tanacetum cinerariifolium flowers synthesize six pyrethrins that function as effective insecticides. trans-Chrysanthemol is an early intermediate in the synthesis of the monoterpene moiety of pyrethrins. Previously, the pyrethrum enzyme chrysanthemyl diphosphate synthase (TcCDS) was shown to catalyze the formation of the prenyl diphosphate compound chrysanthemyl diphosphate (CPP) by condensing two molecules of dimethylallyl diphosphate (DMAPP). Later work also showed that with a low concentration of DMAPP, TcCDS can also remove the diphosphate group to give chrysanthemol. The removal of the phosphate groups from other prenyl diphosphates, such as DMAPP, isopentenyl diphosphate (IPP) and geranyl diphosphate (GPP), was previously shown to occur in two steps. In those cases, the first phosphate group is removed by a member of the Nudix hydrolase protein family, and the second by other unidentified phosphatases. These previously characterized Nudix proteins involved in the hydrolysis of prenyl diphosphates were shown to be cytosolic. Here we report that a plastidic Nudix protein from pyrethrum, designated TcNudix1, has high specificity for CPP and can hydrolyze it to chrysanthemol monophosphate (CMP). TcNudix1 is expressed specifically in the trichomes of the ovaries, where chrysanthemol is produced. TcNudix1 expression patterns and pathway reconstitution experiments presented here implicate the TcNudix1 protein in the biosynthesis of chrysanthemol.

Inhibition of Cell Cycle and Induction of Apoptosis y Ethanol Leaves Extract of Chrysanthemum cinerariifolium (Trev.) In T47D Breast Cancer Cells

Chrysanthemum cinerariifolium (C.cinerariifolium) is a plant of the Asteraceae family, which has been applied by the community as an ornamental plant and traditional medicine. In this study, the effect of C. cinerariifolium leaves extract on inhibition of cell cycle and induction of apoptosis in T47D breast cancer cells was tested and compared to the standard chemotherapy agent. The citotoxic activity of C. cinerariifolium leaves extract against T47D cancer cells and Vero normal cells was tested by MTT method. Profile of apoptosis and cell cycle were observed by flow cytometry method. Based on chemical compounds profil which is tested used TLC showed that C.cinerariifolium leaves extracts contained flavonoid and terpenoid chemical compounds. The result of cytotoxic test showed that leaves extract of C. cinerariifolium was able to inhibit the growth of T47D cancer cell at IC50 418.8μg/mL. Doxorubicin, extracted from Streptomyces peucetius used as treatment in several cancers including breast cancer. Doxorubicin could inhibit the growth of T47D cancer cells in 115.1μg/mL. The results of cell cycle analysis showed that the C. cinerariifolium leaves extract inhibited cell cycle in G0-G1 and S phase, whereas doxorubicin was able to inhibit cell cycle in G0-G1 phase but experienced cell accumulation in G2-M phase. The percentage of apoptosis in cycle was showed in M1 (sub G1) and M5 (multinuclear) phase which treatment of C. cinerariifolium leaves extract was higher than doxorubicin. Therefore, C. cinerariifolium leaves extract has potential activity as anticancer agent causes inhibition of cell cycle and induction apoptosis.

Xylem cavitation isolates leaky flowers during water stress in pyrethrum.

Flowers underpin plant evolution, genetic legacy and global food supply. They are exposed to similar evaporative conditions as leaves, yet floral physiology is a product of different selective forces. We used Tanacetum cinerariifolium, a perennial daisy, to examine the response of flowers to whole-plant water stress, determining if flowers constitute a liability during drought, and how this species has adapted to minimize risk associated with reproduction. We determined the relative transpiration cost of flowers and leaves and confirmed that flowers in this species are xylem-hydrated. The relative water stress tolerance of leaves and flowers then was compared using xylem vulnerability measurements linked with observed tissue damage during an acute drought treatment. Flowers were a major source of water loss during drought but the xylem supplying them was much more vulnerable to cavitation than leaves. This xylem vulnerability segmentation was confirmed by observations that most flowers died whereas leaves were minimally affected during drought. Early cavitation and hydraulic isolation of flowers during drought benefits the plant by slowing the dehydration of perennial vegetative organs and delaying systemic xylem damage. Our results highlight the need to understand flower xylem vulnerability as a means of predicting plant reproductive failure under future drought.