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Phytoremediation is an economical and effective strategy to remove cadmium (Cd) from polluted environments. To improve its efficiency, nanotechnology has been proposed to collaborate with hyperaccumulators in the remediation of Cd-polluted soils. However, the intricate structure-function relationship and the underlying regulatory mechanisms by which nanomaterials regulate Cd migration and conversion within the soil-plant system remained unrevealed. In this study, functional carbon nanodots (FCNs) were modified by doping with nitrogen and (or) sulfur elements. The synthesized nonmetallic atoms-doped FCNs were utilized to investigate their structure-function relationship and the regulatory mechanisms underlying their role in the phytoremediation of Cd-polluted soils by Tagetes patula L. FCNs-based nanomaterials can regulate the migration and bioaccumulation of Cd in the soil-plant system, which exhibits an obvious structural dependency. Specifically, the synergistic application of sulfur doped FCNs and Tagetes patula L. had the highest Cd removal efficiency of 53.2 %, which was 20.1 % higher than Tagetes patula L. alone. The uptake and migration of Cd in the soil-plant system are regulated by FCNs-based nanomaterials through both direct and indirect mechanisms, involving interfacial reactions, plant physiology regulation and environmental influence. This study not only sheds light on the fate of FCNs-based nanomaterials and Cd in the soil-plant system, but also provides innovative nanotools for reinforcing phytoremediation efficiency in contaminated soils., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Qiong Chen, Mei Yan reports financial support was provided by the National Natural Science Foundation of China. Qiong Chen reports financial support was provided by the Natural Science Foundation of Shandong Province. Qiong Chen reports financial support was provided by the China Postdoctoral Science Foundation. Mei Yan reports financial support was provided by the Major Scientific and Technological Innovation Project of Shandong Province. Mei Yan reports financial support was provided by the Jinan City University Integration Development Strategy Project. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Carotenoids play a pivotal role in plant. Tagetes erecta, commonly called marigold, has increasing nutritional and economic value due to its high level of carotenoids in flower. However, the functional genes in the carotenoid biosynthesis of T. erecta have not been studied. In this work, three T. erecta varieties with flowers of yellow, yellow-orange and orange color, respectively, were examined for carotenoids composition and corresponding expression profiling of biosynthetic genes at four developmental stages. The results indicated that the varieties with higher lutein content, orange-flower 'Juwang' and yellow-orange 'Taishan', exhibited significant upregulation of genes in the upstream biosynthesis pathway, especially PDS (phytoene desaturase), PSY (phytoene synthase) and ZDS (zeta-carotene desaturase), whereas downstream carotenoid cleavage genes CCD (carotenoid cleavage dioxygenase) were markedly downregulated throughout flower development in the highest lutein containing variety 'Juwang'. Furthermore, marigold TePDS, TePSYS3 and TeZDS were isolated and transformed into tomato. Overexpression of TePDS or TeZDS resulted in the promotion of fruit ripening and accumulation of carotenoids in the transgenic lines. On the other hand, marigold TePSYS3 showed multiple effects, not only on fruit carotenogenesis but also on pigmentation patterns in vegetative tissues and plant growth. Taken together, the variations in expression profiles of the biosynthetic genes contribute to dynamic change in carotenoid levels and diversity of flower coloration in T. erecta. These functional genes of T. erecta were verified in tomato and provide targets for genetic improvement of fruit carotenoids accumulation., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Chromium pollution, particularly hexavalent chromium [Cr(VI)], may threaten the environment and human health. This study investigated the potential of Tagetes erecta L. (Aztec marigold) for phytoremediation of soil contaminated with Cr(VI), and focused on the effects of varying concentrations of Cr(VI) on both the physicochemical properties of soil and microbiome of Tagetes erecta L. We observed that Tagetes erecta L. showed tolerance to Cr(VI) stress and maintained normal growth under these conditions, as indicated by bioconcentration factors of 0.33-0.53 in shoots and 0.39-0.70 in roots. Meanwhile, the structure and diversity of bacterial communities were significantly affected by Cr(VI) pollution. Specifically, Cr(VI) had a more significant effect on the microbial community structure in the endophytic of Tagetes erecta L. than in the rhizosphere (p < 0.05). The genera Devosia and Methylobacillus were positively correlated with Cr(VI) concentrations. Biomarkers such as Bacilli and Pseudonocardia were identified under the different Cr(VI)-contaminated treatments using LEfSe. In addition, the interaction and stability of the endophytic microbiome were enhanced under Cr(VI) stress. This study explored the interactions between heavy metals, microorganisms, and plants, providing valuable insights for developing in situ bioremediation of Cr(VI)-contaminated soils., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

In the current study, the Cu phytoremediation ability of two ornamental plants, Chrysanthemum indicum L. and Tagetes erecta L., was tracked concerning the growth and physiological responses. Plants were subjected to varying concentrations of Cu (0, 100, 200, and 400 mg/kg) under the pot experiment for 8 weeks. The results showed that the measured growth and physiological characteristics declined in T. erecta shoots and roots at all tested treatments compared with the control. However, in C. indicum at 100 mg/kg, shoot biomass, shoot total soluble protein, and leaves number remained equal to that of the control and then reduced by rising Cu concentrations, compared with the control. Also, results indicated that in C. indicum, after 56 days of exposure to Cu, the chlorophyll pigments content markedly increased and reached a maximum level at 100 mg/kg dose and gradually declined with enhancing Cu concentrations, compared with the control. Other measured growth and physiological parameters decreased in both tissues of C. indicum in response to Cu usage in the growth medium. The carotenoid content of T. erecta decreased in all studied Cu levels in comparison to the control, but in C. indicum remained unaffected up to 200 mg/kg Cu in comparison to the control and then enhanced with increasing Cu level. The augmentation of antioxidant enzyme activity in two species, especially in roots, reflected the incident of Cu stress as demonstrated by elevated MDA and ion leakage levels. Data concerning copper accumulation in tissues, TF, and BAF showed T. erecta is a weak Cu accumulator and seems not to be an appropriate candidate for Cu phytoremediation. However, the Cu content in shoots and roots of C. indicum increased significantly with an increment in applied Cu level. Also, C. indicum accumulated higher Cu concentrations in the roots than in shoots and exhibited TF < 1, 0.1 < BAF root  < 1, and can be considered as a Cu excluder by the phytostabilization mechanism., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: The pursuit for safe and efficacious skin-whitening agents has prompted a dedicated exploration of plant-derived compounds. Notably, Tagetes erecta L. flowers have been used as a medicinal extract and possessed in vitro mushroom tyrosinase activity. However, whether polyphenol-enriched fraction extracted from T. erecta L. flowers (TE) regulates melanogenesis within cellular and animal models has not yet been investigated., Purpose: This study aimed to investigate the effect of TE as a prospective inhibitor of melanogenesis., Methods: Through advanced UPLC-QTof/MS analysis, the components of TE were analyzed. Anti-melanogenic effects of TE were evaluated in α-melanocyte-stimulating hormone (α-MSH)-stimulated B16F10 melanoma cells by measuring cell viability assay, extracellular and intracellular melanin biosynthesis, cyclic adenosine monophosphate (cAMP) production, and melanogenesis-related gene and protein expression. Zebrafish larvae were employed for in vivo studies, assessing both heart rate and melanogenesis. Furthermore, molecular docking analyses were employed to predict the interaction between TE components and the melanocortin 1 receptor (MC1R). Direct binding activity of TE components to MC1R was compared with [Nle 4 , d-Phe 7 ]-MSH (NDP-MSH)., Results: TE was found to contain significant phenolic compounds such as patulitrin, quercetagetin, kaempferol, patuletin, and isorhamnetin. This study revealed that TE effectively inhibits melanin biosynthesis in both in vitro and in vivo models. This inhibition was attributed to interference of TE with the cAMP-cAMP response element-binding protein (CREB)-microphthalmia-associated transcription factor (MITF)-tyrosinase pathway, which plays a pivotal role in regulating melanogenesis. Importantly, TE exhibited the remarkable ability to curtail α-MSH-induced melanogenesis in zebrafish larvae without impacting heart rates. Molecular docking analyses predicted that the components of TE possibly interact with the melanocortin 1 receptor, suggesting their role as potential inhibitors of melanin biosynthesis. However, through the direct binding activity compared with NDP-MSH, any TE components did not directly bind to MC1R, suggesting that TE inhibits α-MSH-induced melanogenesis by inhibiting the cAMP-mediated intracellular signaling pathway. The assessment of anti-melanogenic activity, conducted both in vitro and in vivo, revealed that patulitrin and patuletin exhibited significant inhibitory effects on melanin formation, highlighting their potency as major contributors., Discussion: This investigation demonstrated the considerable potential of TE as a natural remedy endowed with remarkable anti-melanogenic properties. The demonstrated capacity of TE to attenuate melanin production by modulating the cAMP-CREB-MITF-tyrosinase pathway underscores its central role in management of disorders associated with excessive pigmentation. Importantly, the implications of these findings extend to the cosmetics industry, where TE emerges as a prospective and valuable ingredient for the formulation of skin-whitening products. The elucidated interactions between TE components and MC1R not only provide insight into a potential mechanism of action but also elevate the significance of this study. In summary, this study not only contributes to our comprehension of pigmentation-related conditions but also firmly establishes TE as a secure and natural strategy for the regulation of melanin production. The innovative aspects of TE propel it into the forefront of potential interventions, marking a noteworthy advancement in the pursuit of effective and safe solutions for pigmentation disorders., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier GmbH. All rights reserved.)

Tagetes erecta and Ocimum basilicum are medicinal plants that exhibit anti-inflammatory effects against various diseases. However, their individual and combined effects on osteoarthritis (OA) are unknown. Herein, we aimed to demonstrate the effects of T. erecta, O. basilicum , and their mixture, WGA-M001, on OA pathogenesis. The administration of total extracts of T. erecta and O. basilicum reduced cartilage degradation and inflammation without causing cytotoxicity. Although WGA-M001 contained lower concentrations of the individual extracts, it strongly inhibited the expression of pathogenic factors. In vivo OA studies also supported that WGA-M001 had protective effects against cartilage destruction at lower doses than those of T. erecta and O. basilicum . Moreover, its effects were stronger than those observed using Boswellia and Perna canaliculus. WGA-M001 effectively inhibited the interleukin (IL)-1β-induced nuclear factor kappa-light-chain-enhancer of the activated B cell (NF-κB) pathway and ERK phosphorylation. Furthermore, RNA-sequence analysis also showed that WGA-M001 decreased the expression of genes related to the IL-1β-induced NF-κB and ERK signaling pathways. Therefore, WGA-M001 is more effective than the single total extracts of T. erecta and O. basilicum in attenuating OA progression by regulating ERK and NF-κB signaling. Our results open new possibilities for WGA-M001 as a potential therapeutic agent for OA treatment.

Tagetes erecta L. (marigold), a common landscaping flower widely cultivated in America, Africa, Asia and Europe, is the fundamental source of carotenoids (especially lutein) in food and pharmaceutical industry. Carotenoids are well-known to possess various healthy and beneficial biological activities such as eye protection, anti-aging, and anti-inflammatory. In our exploitation of carotenoid-derived products from T. erecta, nine previously undescribed compounds including seven megastigmane-type norsesquiterpenoids (1-7), one carotenoid-derived sesquiterpenoid (8), and one natural 3-hydroxyl-α-ionylideneacetic acid derivative (9), along with twelve known compounds (10-21), were afforded from the 95% ethanol extract of the petals of T. erecta. Their planar chemical structures and the absolute configurations were established by analysis of the extensive spectroscopic data including HRESI-MS, 1D/2D NMR and the simulation of ECD. Further, a plausible biosynthesis pathway for compounds 1-20 is proposed., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper, (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Contamination of land and aquatic ecosystems with heavy metals (HMs) is a global issue having the persistent potential to damage the quality of food and water. In the present study, Tagetes erecta L. plants were used to assess their potential to uptake HMs from wastewater. Plants were grown in soil for 20 days and then transplanted in hydroponic system containing Hoagland nutrient solution. After more than 15 days of growth, plants were then subjected to wastewater from tannery and surgical industries in different concentrations ranging from 25 to 100% in combination of citric acid (5 and 10 mM). After 6 weeks of treatment, plants were collected and segmented into roots, stem, and leaves for characterizing the morphological properties including plant height, roots length, fresh and dry mass of roots, stem, and leaves. For evaluation of the effect of wastewater on the plants, photosynthetic pigments; soluble proteins; reactive oxygen species (ROS); antioxidant enzymes SOD, POD, CAT, and APX; and metal accumulation were analyzed. Application of industrial wastewater revealed a significant effect on plant morphology under wastewater treatments. Overall growth and physiological attributes of plant decreased, and metal accumulation enhanced with increasing concentration of wastewater. Similarly, the production of ROS and antioxidant enzymes were also increased. Chlorophyll, protein content, and enzyme production enhanced with CA (5 and 10 mM) mediation; however, ROS production and EL were reduced. Metals analysis showed that the maximum accumulation of Pb was in roots, while Cr and Ni in the stem which further increased under CA mediation. Overall, the metal accumulation ability was in the order of Pb > Ni > Cr under CA., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Pyrethrins are widely accepted as natural insecticides and offers several advantages of synthetic compounds, i.e., rapidity of action, bioactivity against a wide range of insects, comparatively lesser costs and the like. A significant source of pyrethrin is Chrysanthemum cinerariaefolium; cultivated in restricted areas, as a result; natural pyrethrins are not produced in a large amount that would meet the ongoing global market demand. However, increasing its content and harnessing the desired molecule did not attract much attention. To enhance the production of pyrethrins in Tagetes erecta, the Chrysanthemyl diphosphate synthase (CDS) gene was overexpressed under the promoter CaMV35S. Hypocotyls were used as explant for transformation, and direct regeneration was achieved on MS medium with 1.5 mg L -1 BAP and 5.0 mg L -1 GA3. Putative transgenics were screened on 10 mgL -1 hygromycin. After successful regeneration, screening and rooting process, the transgenic plants were raised inside the glass house and PCR amplification of CDS and HYG-II was used to confirm the transformation. Biochemical analysis using HPLC demonstrated the expression levels of the pyrethrin, which was approx. twenty-six fold higher than the non-transformed Tagetes plant., (© 2022. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

The use of degradable chelating agents to facilitate phytoextraction is a promising low-cost method for the remediation of heavy metal-contaminated soils. However, there are few studies on how plants and soils respond to the chelating agents. In this study, the responses of French marigold (Tagetes patula L.) and soil cadmium (Cd) to the chelator tetrasodium glutamate (GLDA) was investigated in a 180 d field trial. Five GLDA treatments (0, 292.5, 585, 1170, and 2340 kg hm -2 ) were carried out in a Cd-contaminated soil (0.47 mg kg -1 ) under French marigold plantation. The results showed that the application of GLDA promoted the transformation of other forms of Cd in soil to exchangeable state, and the exchangeable Cd and Fe-Mn oxide bound state increased by 42.13% and 32.97% (p < 0.05), respectively. The cell wall Cd accumulations significantly increased 9.39% (p < 0.05) and the percentages of soluble fractions increased by 460.33% (p < 0.05). Furthermore, increases occurred in soil pH, as well as DOC and DTPA-Cd contents with increasing the total amount of GLDA. The composite application of GLDA (2340 kg hm -2 ) with French marigold reduced the total soil Cd content by 7.59% compared with the soil background. Altogether, results of this study suggested that the application of GLDA can effectively activate soil Cd and enhance the capability of French marigold for the remediation of Cd-contaminated soils., (© 2022. The Author(s).)

Essential oils (EO) are plant extracts widely used for various pharmacological applications and their antioxidant and anti-inflammatory effects have received a lot of attention because they hold the potential to reduce oxidative stress, and neuroinflammation, alterations involved in the pathophysiology of major depressive disorder. This study examined the benefits of administration of flower EO of the Tagetes minuta (10 and 50 mg/kg, intragastric route) in attenuating behavioral, neurochemical, and neuroendocrine changes in animal models of depressive-like behavior induced by acute restraint stress and lipopolysaccharide (0.83 mg/kg, intraperitoneally). We demonstrated that the treatment of mice with flower EO of the T. minuta reversed the depressive-like behavior induced by stress or inflammatory challenge in mice. This effect is most likely due to the reversal of oxidative stress in the hippocampus of mice, the decrease in plasma corticosterone levels, and restoration of the mRNA levels of brain-derived neurotrophic factor, phosphatidylinositol-3-kinase, protein kinase B, and extracellular signal-regulated kinase 2. As an outcome, flower EO of the T. minuta has promising antidepressant properties and could be considered for new therapeutic strategies for major depressive disorder., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Members of AP1/FUL subfamily genes play an essential role in the regulation of floral meristem transition, floral organ identity, and fruit ripping. At present, there have been insufficient studies to explain the function of the AP1/FUL -like subfamily genes in Asteraceae. Here, we cloned two euAP1 clade genes TeAP1-1 and TeAP1-2 , and three euFUL clade genes TeFUL1 , TeFUL2 , and TeFUL3 from marigold ( Tagetes erecta L.). Expression profile analysis demonstrated that TeAP1-1 and TeAP1-2 were mainly expressed in receptacles, sepals, petals, and ovules. TeFUL1 and TeFUL3 were expressed in flower buds, stems, and leaves, as well as reproductive tissues, while TeFUL2 was mainly expressed in flower buds and vegetative tissues. Overexpression of TeAP1-2 or TeFUL2 in Arabidopsis resulted in early flowering, implying that these two genes might regulate the floral transition. Yeast two-hybrid analysis indicated that TeAP1/FUL proteins only interacted with TeSEP proteins to form heterodimers and that TeFUL2 could also form a homodimer. In general, TeAP1-1 and TeAP1-2 might play a conserved role in regulating sepal and petal identity, similar to the functions of MADS-box class A genes, while TeFUL genes might display divergent functions. This study provides a theoretical basis for the study of AP1/FUL -like genes in Asteraceae species.

Marigold (Tagetes erecta), as one member of Asteraceae family, bears a typical capitulum with two morphologically distinct florets. The SEPALLATA genes are involved in regulating the floral meristem determinacy, organ identity, fruit maturation, seed formation, and plant architecture. Here, five SEP-like genes were cloned and identified from marigold. Sequence alignment and phylogenetic analysis demonstrated that TeSEP3-1, TeSEP3-2, and TeSEP3-3 proteins were grouped into SEP3 clade, and TeSEP1 and TeSEP4 proteins were clustered into SEP1/2/4 clade. Quantitative real-time PCR analysis revealed that TeSEP1 and TeSEP3-3 were broadly expressed in floral organs, and that TeSEP3-2 and TeSEP4 were mainly expressed in pappus and corollas, while TeSEP3-1 was mainly expressed in two inner whorls. Ectopic expression of TeSEP1, TeSEP3-2, TeSEP3-3, and TeSEP4 in arabidopsis and tobacco resulted in early flowering. However, overexpression of TeSEP3-1 in arabidopsis and tobacco caused no visible phenotypic changes. Notably, overexpression of TeSEP4 in tobacco decreased the number of petals and stamens. Overexpression of TeSEP1 in tobacco led to longer sepals and simpler inflorescence architecture. The comprehensive pairwise interaction analysis suggested that TeSEP proteins had a broad interaction with class A, C, D, E proteins to form dimers. The yeast three-hybrid analysis suggested that in ternary complexes, class B proteins interacted with TeSEP3 by forming heterodimer TePI-TeAP3-2. The regulatory network analysis of MADS-box genes in marigold further indicated that TeSEP proteins played a "glue" role in regulating floral organ development, implying functional conservation and divergence of MADS box genes in regulating two-type floret developments. This study provides an insight into the formation mechanism of floral organs of two-type florets, thus broadening our knowledge of the genetic basis of flower evolution., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Protective effect of Tagetes erecta flowers essential oils was investigated on oxidative stress, immune response, inflammation, and apoptosis against N-methyl-N'nitro-N-nitroguanidine (MNNG) induced gastric cancer in rats. Essential oil were extracted from Tagetes erecta flowers and analyzed using gas chromatography-mass spectrometry (GC-MS). For observing a protective effect against MNNG induced gastric cancer, we divided rats into 4 groups (group A to D) having 10 rats in each group. Performed various experiments and measured a different parameters to investigate antioxidant activity, immune response, anti-inflammatory and anti-apoptotic activity. The levels of malondialdehyde were markedly increased in the presence of N-methyl-N'nitro-N-nitroguanidine, whereas, the antioxidant activities of superoxide dismutase, and catalase were lowered in the treated rats in contrast with the control. Intervention with TEEO to gastric cancer-induced rats upregulated the redox status and the activity of the immune system to decrease cancer risk. The proinflammatory cytokines (IL-6 and TNF-α) secretions that were induced by MNNG were markedly inhibited by TEEO. Administration of TEEO also significantly reduced terminal deoxynucleotidyl transferase dUTP nick end labeling positive gastric cancer cells, expression of mRNA of caspase-3, and Bax. Whereas, the expression of Bcl-2 was increased. Additionally, downregulation of nuclear factor E2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) and IκBα degradation and the nuclear factor-κB (NF-κB) p65 expression in tissues of the stomach of MNNG-induced-rats were markedly elevated due to TEEO. This suggested possession of TEEO with a protective shield against MNNG induced gastric cancer by the exertion of antioxidative stress, anti-apoptotic response, the anti-inflammatory response through Nrf2/HO-1, and NF-κB signaling pathways.

According to the 'novel weapons hypothesis', invasive success depends on harmful plant biochemicals, including allelopathic antimicrobial roots exudate that directly inhibit plant growth and soil microbial activity. However, the combination of direct and soil-mediated impacts of invasive plants via allelopathy remains poorly understood. Here, we addressed the allelopathic effects of an invasive plant species (Rhus typhina) on a cultivated plant (Tagetes erecta), soil properties and microbial communities. We grew T. erecta on soil samples at increasing concentrations of R. typhina root extracts and measured both plant growth and soil physiological profile with community-level physiological profiles (CLPP) using Biolog Eco-plates incubation. We found that R. typhina root extracts inhibit both plant growth and soil microbial activity. Plant height, Root length, soil organic carbon (SOC), total nitrogen (TN) and AWCD were significantly decreased with increasing root extract concentration, and plant above-ground biomass (AGB), below-ground biomass (BGB) and total biomass (TB) were significantly decreased at 10 mg·mL-1 of root extracts. In particular, root extracts significantly reduced the carbon source utilization of carbohydrates, carboxylic acids and polymers, but enhanced phenolic acid. Redundancy analysis shows that soil pH, TN, SOC and EC were the major driving factors of soil microbial activity. Our results indicate that strong allelopathic impact of root extracts on plant growth and soil microbial activity by mimicking roots exudate, providing novel insights into the role of plant-soil microbe interactions in mediating invasion success., Competing Interests: The authors have declared that no competing interests exist.

Marigold (Tagetes erecta L.) is an important ornamental plant with a wide variety of flower colors. Despite its economic value, few biochemical and molecular studies have explored the generation of flower color in this species. To study the mechanism underlying marigold petal color, we performed a metabolite analysis and de novo cDNA sequencing on the inbred line 'V-01' and its petal color mutant 'V-01M' at four flower developmental stages. A total of 49,217 unigenes were identified from 24 cDNA libraries. Based on our metabolites and transcriptomic analyses, we present an overview of carotenoid biosynthesis, degradation, and accumulation in marigold flowers. The carotenoid content of the yellow mutant 'V-01M' was higher than that of the orange inbred line 'V-01', and the abundances of the yellow compounds lutein, neoxanthin, violaxanthin, zeaxanthin, and antheraxanthin were significantly higher in the mutant. During flower development, the carotenoid biosynthesis genes were upregulated in both 'V-01' and 'V-01M', with no significant differences between the two lines. By contrast, the carotenoid degradation genes were dramatically downregulated in the yellow mutant 'V-01M'. We therefore speculate that the carotenoid degradation genes are the key factors regulating the carotenoid content of marigold flowers. Our research provides a large amount of transcriptomic data and insights into the marigold color metabolome.

The aim of this study was to characterize carotenoids and flavonoids present in French marigold flowers ( Tagetes patula "Durango Red") as well as to assess the effects of harvest dates and postharvest treatments on these compounds. Carotenoids and flavonoids were quantified using their respective standards or semiquantified using relevant related standards. Lutein and its derivatives largely dominated the flower carotenoids, while the flavonoids were diverse with patuletin leading the list. Of the different postharvest treatments, ensilage leads to the highest content of carotenoids (from 5.0 to 7.8 g kg -1 dw) and flavonoids (from 19 to 50 g kg -1 dw). The composition of individual flavonoids was greatly influenced by different postharvest treatments, while the influence of harvest dates was secondary. Ensilage and drying induced separate metabolic pathways leading to degradation of high-molecular glycosidic compounds, converting the compounds either to their aglycones or into the intermediate flavonoid glycosides. We conclude that according to the intended industrial application, different postharvest techniques can be employed to acquire desired flavonoids on a large scale.

More than 70% of vascular plant species live in symbiosis with arbuscular mycorrhizal (AM) fungi. In addition to other effects this symbiosis is known for its significance for plant nutrition including iron. Fungal iron mobilization from soil is commonly dependent on siderophores. This study reports on a search for such iron-chelators in root tissue of Tagetes patula nana var. plena colonized by Gigaspora margarita. The AM colonized plants and uninoculated controls were grown under strictly axenic conditions. HPLC analyses of aqueous extracts from plant roots have provided clear evidence for the presence of a rhizoferrin type siderophore, named glomuferrin, in root tissue of mycorrhizal seedlings. Results from HPLC analytical work are seconded by molecular biological data: A BLASTp search revealed that the AM fungal species Gigaspora rosea, Rhizophagus irregularis (formerly Glomus intraradices), Glomus cerebriformis and Diversispora epigea encode a non-ribosomal peptide synthetase (NRPS)-independent siderophore synthase (NIS), which is homologous to the rhizoferrin synthetase of Rhizopus delemar. Thus this study indicates that the biosynthesis of rhizoferrin type siderophores such as glomuferrin (= bis-imidorhizoferrin) may be widespread in the AM symbiosis.

Tagetes lucida Cav. is an ancient medicinal plant used to treat different ailments involving neurological diseases and pain. However, scientific studies to validate their medicinal properties as analgesic have not been described. The aim of this study was to evaluate the T. lucida antinociceptive response using pain models. Bioactive compounds and a possible mechanism of action were also explored. Dose-response effects of an ethanol crude extract were investigated in the writhing and formalin tests in mice and rats, respectively. The extract was fractionated to isolate active fractions and bioactive compounds (quercetagetin 7‑O‑β‑d‑glucoside and 6,7‑dimethoxycoumarin) using the formalin test. The antinociceptive effects were compared to the reference drugs (tramadol 10 mg/kg, diclofenac 50 mg/kg, and/or ketorolac 1 mg/kg, i.p.). The ethanol extract was explored in the presence of naloxone (3 mg/kg, i.p. a non-selective opioid receptor antagonist) and WAY100635 (0.5 mg/kg, s.c., a selective 5-HT 1A receptor antagonist) to screen their participation as possible inhibitory mechanisms involved in the antinociceptive response of T. lucida. The ethanol crude extract, fractions, and pure compounds caused a significant antinociceptive response resembling the effect of the reference drugs. Both opioid and 5-HT 1A receptors participated in the analgesic -like activity of the extract, which did not produce gastric damage. On the contrary, the gastric damage produced as an adverse effect of the analgesic ketorolac was prevented when combined with the extract. In conclusion, these preliminary data provide evidence and give support to the properties attributed to T. lucida in the traditional medicine to alleviate pain., (Copyright © 2019. Published by Elsevier Inc.)

Investigation of yellow flower extract of Tagetes patula L. led to the identification of an aggregate of five phytoceramides. Among them, (2R)-2-hydroxy-N-[(2S,3S,4R,8E)-1,3,4-trihydroxyicos-8-en-2-yl]icosanamide, (2R)-2-hydroxy-N-[(2S,3S,4R,8E)-1,3,4-trihydroxyicos-8-en-2-yl]heneicosanamide, (2R)-2-hydroxy-N-[(2S,3S,4R,8E)-1,3,4-trihydroxyicos-8-en-2-yl]docosanamide, and (2R)-2-hydroxy-N-[(2S,3S,4R,8E)-1,3,4-trihydroxyicos-8-en-2-yl]tricosanamide were identified as new compounds and termed as tagetceramides, whereas (2R)-2-hydroxy-N-[(2S,3S,4R,8E)-1,3,4-trihydroxyicos-8-en-2-yl]tetracosanamide was a known ceramide. A steroid (β-sitosterol glucoside) was also isolated from the subsequent fraction. The structures of these compounds were determined on the basis of spectroscopic analyses, as well as chemical method. Several other compounds were also identified by GC/MS analysis. The fractions and some commercial products, a ceramide HFA, β-sitosterol, and stigmasterol were evaluated against an economically important cyst nematode, Heterodera zeae. Ceramide HFA showed 100 % mortality, whereas, β-sitosterol and stigmasterol were 40-50 % active, at 1 % concentration after 24 h of exposure time, while β-sitosterol glucoside revealed no activity against the nematode., (© 2019 Wiley-VHCA AG, Zurich, Switzerland.)

The development of techniques to non-destructively monitor allelochemical dynamics in soil using polydimethylsiloxane (PDMS) microtubing (silicone tubing microextraction, or STME) provides a means to test important ecological hypotheses regarding the roles of these compounds in plant-plant interactions. The objective of this study was to investigate the impact of intra- and interspecific competition on the exudation of thiophenes by marigolds (Tagetes patula L.). Marigolds were grown at a density of 1, 3 and 5 plants in pots (8.75 × 8.75 cm) containing two STME samplers. An additional treatment included one marigold surrounded by four velvetleaf (Abutilon theophrasti L.) plants. Marigold roots released two primary thiophenes, 3-buten-1-ynyl)-2,2'-bithienyl and α-terthienyl, which are readily absorbed by silicone microtubing. Thiophene exudation was monitored over the period 15-36 days after planting, at 2-5 day intervals. At the end of the study, root and soil samples were also analyzed for thiophene content. Thiophene production per plant increased over time, and thiophene release was strongly correlated with plant size. These results indicate that thiophene release in this study was passively controlled by resource availability. However, poor growth of velvetleaf plants competing with marigold suggests that thiophenes negatively influenced velvetleaf growth. This study, then, provides indirect evidence that thiophene exudation is insensitive to neighbor identity but differentially effective in inhibiting the growth of heterospecific neighbors.

The soil cadmium (Cd) availability and uptake by Tagetes patula grown in two soil types contaminated with Cd and amended with N fertilizer and wheat straw were studied in a pot-culture experiment. The results indicated that N fertilizer treatment (N) and N fertilizer plus straw treatment (NS) promoted T. patula growth, while straw treatment (S) decreased T. patula biomass relative to the control. NS and S treatments increased Cd mobility in the soil and facilitated its uptake by T. patula in Acidic Ferralsols (AF) and Calcaric Cambisols (CC), but the promotion effect was much greater in CC than in AF. The Cd concentrations in the Tagetes shoots in the S and NS treatments were 40% and 27% greater, respectively, than those in the control treatment for AF, and 111% and 80% greater, respectively, for CC. Decreases in soil pH and increases in dissoluble organic carbon concentration after adding N fertilizer and straw were associated with an increase in soil Cd availability and in Cd uptake by T. patula. The results indicate that the NS treatment can alter the soil microenvironment, increasing Cd bioavailability and thus facilitating Cd uptake by T. patula. This work highlights that the combined application of N fertilizer with straw may be a useful way to increase the phytoextraction efficiency of Cd-contaminated soil by the Cd-hyperaccumulator T. patula., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Lutein is a plant pigment very important for eye health in humans. Its bioavailability in humans is better from egg yolk than from dietary supplements. The aim of this research was to determine the influence of lutein (marigold extract powder) supplemented to laying hens' feed rich in omega-3 fatty acids on the content of lutein, fatty acid profile in egg yolks and yolk color. The diets that contained 5% of oils as a source of omega-3 fatty acids were supplemented with 0, 1 and 2 g kg -1 of marigold powder., Results: The best enrichment of eggs with lutein was achieved by supplementing 2 g marigold kg -1 of feed. Yolk color was significantly intensified (P < 0.001) by supplementing 1 g marigold kg -1 of feed. The content of total saturated fatty acids, monounsaturated fatty acids and n-6 polyunsaturated fatty acids (PUFA) remained unchanged, whereas the content of total n-3 PUFA (P = 0.017) and docosahexaenoic acid (P < 0.001) was higher in the group with 2 g marigold kg -1 of feed. This group also had the most favorable ratio of n-6:n-3 PUFA., Conclusion: Results of this research showed that addition of marigold powder to laying hens' feed significantly increased egg lutein content and yolk color, and altered the fatty acid profile in yolk. Eggs with increased lutein content and a favorable profile of fatty acids are a good source of these ingredients in human nutrition. © 2018 Society of Chemical Industry., (© 2018 Society of Chemical Industry.)

In recent years, ornamental plants have come under investigation as phytoremediation agents. In addition to reducing contaminant concentrations in soil, such plants support local economies by serving social (e.g., religious) and decorative purposes. Greenhouse studies investigated the phytostabilization potential of soil cadmium (Cd) by five cultivars of marigold (Tagetes erecta), a common ornamental flower in Asia. The effects of organic (cattle manure and pig manure) and inorganic (leonardite and Osmocote®) amendments in supporting plant growth and enhancing Cd uptake were also examined. Marigold cultivars Babuda and Sunshine grown in soil supplemented with pig manure produced the greatest biomass and experienced greatest Cd accumulation and flower production. In all treatments, plant parts accumulated Cd in the following order: root > shoot ≈ flower. Furthermore, Babuda and Sunshine cultivars had a high phytostabilization potential as evidenced by translocation factors < 1 and bioconcentration factors > 1 for roots. It is proposed that Babuda and Sunshine marigold cultivars be applied toward Cd phytostabilization while enhancing local economies as an ornamental species.

Genomic and transcriptomic sequences of Tagetes erecta are very limited in public databases, despite its nutritional and economical value. In this study, nine cDNA libraries were constructed from leaves, immature and mature flowers and sequenced using Illumina Hiseq 2000. Over 45.66 Gb nucleotides were generated and a total of 72,499 unigenes were assembled, 34,892 (48.13%) of which were annotated in NR, Swiss-prot, COG, GO, KOG, KEGG and Pfam. 11,721 differentially expressed genes were identified in leaves, immature flowers and mature flowers. The differentially expressed genes between immature flowers and mature flowers were mainly involved in photosynthesis and secondary metabolite biosynthesis. Additionally, the catalysis-related unigenes and their expression involved in carotenoids biosynthesis were determined. Using our newly identified reference genes as internal control, the expression profiles of carotenoids biosynthetic genes were verified by real-time qRT-PCR, and four of the unigenes were cloned for full length sequences confirmation. Furthermore, gene expansions occurred among the catalytic gene families in carotenoids biosynthesis pathway, which might explain the high pigment content in T. erecta., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Botanical fungicides comprise attractive alternatives to chemical fungicides because of their environmental compatibility. Flavonoids extracted from Tagetes erecta L. have an inhibitory effect on fusarium wilt in watermelons caused by Fusarium oxysporum f. sp. niveum (FON). In this study, we synthesized one of these flavonoids, 2,5-dicyclopentylidene cyclopentanone (Tagetes erecta L. fungicide (TEF)) and assessed its activity against FON. In vitro, TEF inhibited FON growth and killed FON cells directly. TEF also affected FON cell physiology and mycelial structure. In watermelon plants with fusarium wilt, TEF protected the leaf cell structure and improved the germination rate of infected seeds while increasing overall plant resistance. A TEF-resistant mutant (FONM) was created by chemical mutagenesis. FON and FONM were analysed using iTRAQ and RNA-Seq, which identified 422 differentially expressed proteins and 7817 differentially expressed mRNAs in the proteome and transcriptome, respectively. The FONM mutations caused changes in the cell membrane and cell wall, which may constitute the site of action of TEF. Together, these results demonstrate that TEF could effectively control the watermelon fusarium wilt caused by FON, possibly through the inhibition of sterol biosynthesis. The data presented here suggest that TEF represents a new potential botanical anti-fungal drug.

Tagetes erecta thrived in phytotoxic levels of cadmium (Cd; 50-300 mg kg -1 ) and copper (Cu; 150-400 mg kg -1 ) for 21 d. It accumulated high metal contents in its above-ground tissues (3675 mg Cd kg -1 dry wt and 3948 mg Cu kg -1 dry wt) and showed greater root to shoot translocation and a high extraction coefficient, all of which pointed toward its potential as a hyperaccumulator. Both Cd stress and Cu stress reduced the plant biomass, foliar area, and number. In addition, there were significant declines in pigment contents as well as boosts in lipid peroxidation levels. However, the plant triggered a number of stress-mitigation strategies to abate reactive oxygen species formed as a result of Cd/Cu excess, mostly via significant augmentation of superoxide dismutase, catalase, glutathione peroxidase, and ascorbate peroxidase activities. Though the root and leaf anatomy revealed some signs of toxic symptoms at 50 mg Cd kg -1 and at 150 mg Cu kg -1 , as evidenced by scanning electron microscopy, the root showed maximum tolerance, with tolerance indexes of 85.4% and 91.7%, respectively. Energy-dispersive X-ray microanalysis showed specific Ca 2+ signals in both root and stomata, which could be associated with a specific signaling pathway leading to increased root metal uptake and stomatal closure. Environ Toxicol Chem 2017;36:2533-2542. © 2017 SETAC., (© 2017 SETAC.)

Species of Tagetes , which belong to the family Asteraceae show different characteristics including, bloom size, shape, and color; plant size; and leaf shape. In this study, we determined the differences in primary metabolites and carotenoid yields among six cultivars from two Tagetes species, T. erecta and T. patula . In total, we detected seven carotenoids in the examined cultivars: violaxanthin, lutein, zeaxanthin, α-carotene, β-carotene, 9- cis -β-carotene, and 13- cis -β-carotene. In all the cultivars, lutein was the most abundant carotenoid. Furthermore, the contents of each carotenoid in flowers varied depending on the cultivar. Principal component analysis (PCA) facilitated metabolic discrimination between Tagetes cultivars, with the exception of Inca Yellow and Discovery Orange. Moreover, PCA and orthogonal projection to latent structure-discriminant analysis (OPLS-DA) results provided a clear discrimination between T. erecta and T. patula . Primary metabolites, including xylose, citric acid, valine, glycine, and galactose were the main components facilitating separation of the species. Positive relationships were apparent between carbon-rich metabolites, including those of the TCA cycle and sugar metabolism, and carotenoids.

According to the floral organ development ABC model, B class genes specify petal and stamen identification. In order to study the function of B class genes in flower development of Tagetes erecta, five MADS-box B class genes were identified and their expression and putative functions were studied. Sequence comparisons and phylogenetic analyses indicated that there were one PI-like gene-TePI, two euAP3-like genes-TeAP3-1 and TeAP3-2, and two TM6-like genes-TeTM6-1 and TeTM6-2 in T. erecta. Strong expression levels of these genes were detected in stamens of the disk florets, but little or no expression was detected in bracts, receptacles or vegetative organs. Yeast hybrid experiments of the B class proteins showed that TePI protein could form a homodimer and heterodimers with all the other four B class proteins TeAP3-1, TeAP3-2, TeTM6-1 and TeTM6-2. No homodimer or interaction was observed between the euAP3 and TM6 clade members. Over-expression of five B class genes of T. erecta in Nicotiana rotundifolia showed that only the transgenic plants of 35S::TePI showed altered floral morphology compared with the non-transgenic line. This study could contribute to the understanding of the function of B class genes in flower development of T. erecta, and provide a theoretical basis for further research to change floral organ structures and create new materials for plant breeding., Competing Interests: The authors have declared that no competing interests exist.

Polluted agricultural soils are a serious problem for food safety, with phytoremediation being the most favorable alternative from the environmental perspective. However, this methodology is generally time-consuming and requires the cessation of agriculture. Therefore, the purpose of this study was to evaluate two potential phytoextractor plants (the native species Bidens pilosa and Tagetes minuta) co-cropped with lettuce growing on agricultural lead-polluted soils. The concentrations of Pb, as well as of other metals, were investigated in the phytoextractors, crop species, and in soils, with the potential risk to the health of consumers being estimated. The soil parameters pH, EC, organic matter percentage and bioavailable lead showed a direct relationship with the accumulation of Pb in roots. In addition, the concentration of Pb in roots of native species was closely related to Fe (B. pilosa, r = 0.81; T. minuta r = 0.75), Cu (T. minuta, r = 0.93), Mn (B. pilosa, r = 0.89) and Zn (B. pilosa, r = 0.91; T. minuta, r = 0.91). Our results indicate that the interaction between rhizospheres increased the phytoextraction of lead, which was accompanied by an increase in the biomass of the phytoextractor species. However, the consumption of lettuce still revealed a toxicological risk from Pb in all treatments.

The principal impediment for Pb uptake by plants is the Casparian strip in roots. It prevents metals reaching the xylem, thereby hampering translocation to the aerial organs. In the root apices, young root cells have thin cell walls and the Casparian strip is not completely developed, which could facilitate Pb uptake by roots at these vulnerable points. However, as the phytotoxic effects of Pb reduce root growth and enhance suberization, entry of Pb into the plant is avoided. We propose that the application of root growth promotors could be an important complement in the phytoextraction of Pb from polluted soils, due to their effects on produced biomass, Pb toxicity, and root exudate production. A greenhouse experiment was carried on to evaluate the auxin application effect on the Pb uptake of Bidens pilosa and Tagetes minuta. These species were sensitive to auxins, but the phytotoxic effect of Pb was not reversed by this treatment. Root exudates capable of extracting Pb were produced only when the species were grown in highly polluted soils, indicating a behavioral response to Pb exposure which is desirable for phytoremediation., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Pot experiments were conducted to evaluate the phytoremediation of B[a]P contaminated soil using two ornamental plants (Tagetes patula and Mirabilis jalapa). The results showed that the dry biomass of two plants was increased at low B[a]P contaminated soil and then inhibited with increasing B[a]P concentrations. It exhibited a significantly positive linear relationship between B[a]P absorption in roots, stems, leaves and shoots of the tested plants and the concentration of B[a]P in soils (P<0.01). Meanwhile, the contents of B[a]P in different tissues of the plants increased with growing time. After planting T. patula and M. jalapa, plant-promoted biodegradation of B[a]P was account for 79.5-99.8% and 71.1-99.9%, respectively, whereas the amount of B[a]P dissipation enhancement was only 0.2-20.5% and 0.1-28.9%, respectively. Moreover, low bioaccumulation factor (BF) and translocation factor (TF) values indicated that T. patula and M. jalapa took up B[a]P from contaminated soil and transferred them to the aerial parts with low efficiency. The B[a]P removal rates in rhizosphere soils at different growing stages of T. patula and M. jalapa were 2.7-26.8% and 0.4%-33.9%, respectively, higher than those of non-rhizopshere soils. Therefore, the presence of T. patula and M. jalapa roots was effective in promoting the phytoremediation of B[a]P contaminated soils., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Microalgae have faster growth rates and more free lutein than marigold flowers, the current source of lutein. However, no commercial lutein production uses microalgae. This review compares lutein content, cultivation, harvesting, cell disruption, and extraction stages of lutein production using marigold flowers and those using microalgae as feedstock. The lutein production rate of microalgae is 3-6 times higher than that of marigold flowers. To produce 1 kg of pure lutein, marigolds need more land and water, but require less nutrients (N, P, K) and less energy than microalgae. Since lutein is tightly bound in microalgae and microalgae are small, cell disruption and subsequent extraction stages consume a considerable amount of energy. Research and development of affordable lutein production from microalgae are discussed., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Both nitric oxide (NO) and reactive oxygen species (ROS) are very important signal molecules, but the roles they play in signal transduction of sulfur dioxide (SO2) induced toxicities on ornamental plants is not clear. In this study, the functions of NO and ROS in SO2-induced death of lower epidermal guard cells in ornamental plant Tagetes erecta were investigated. The results showed that SO2 derivatives (0.4-4.0 mmol L(-1) of final concentrations) could reduce the guard cells' viability and increase their death rates in a dose-dependent manner. Meanwhile, the significant increase of cellular NO, ROS, and Ca(2+) levels (P<0.05) and typical apoptosis features including nucleus condensation, nucleus break and nucleus fragmentation were observed. However, exposure to 2.0 mmol L(-1) of SO2 derivatives combined with either NO antagonists (NO scavenger c-PTIO; nitrate reductase inhibitor NaN3; NO synthase inhibitor L-NAME), ROS scavenger (AsA or CAT) or Ca(2+) antagonists (Ca(2+) scavenger EGTA or plasma membrane Ca(2+) channel blocker LaCl3) can effectively block SO2-induced guard cells death and corresponding increase of NO, ROS and Ca(2+) levels. In addition, addition of L-NAME or AsA in 2.0 mmol L(-1) of SO2 derivatives led to significant decrease in the levels of NO, ROS and Ca(2+), whereas addition of LaCl3 in them just resulted in the decrease of Ca(2+) levels, hardly making effects on NO and ROS levels. It was concluded that NO and ROS were involved in the apoptosis induced by SO2 in T. erecta, which regulated the cell apoptosis at the upstream of Ca(2+)., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Sulfur dioxide (SO2) exposure is associated with increased risk of various damages to plants. However, little is known about the defense response in ornamental plants. In this study, an artificial fumigation protocol was carried out to study the defense potential of the glutathione (GSH)-ascorbate (AsA) dependent detoxification pathway to SO2 exposure in Tagetes erecta. The results show that when the plants were exposed to different doses of SO2 (0, 15, 30, 50 or 80 mg m(-3)) for different times (6, 12, 18, 24 or 33 h), SO2 induced oxidative stress was confirmed by the increased hydrogen peroxide (H2O2), malondialdehyde (MDA) and relative conductivity of membrane (RC) in a dose-dependent manner for different exposure times. However, the increased levels for H2O2, MDA and RC were not significant vis-a-vis the control when SO2 doses and exposure times were lower than 15 mg m(-3)/33 h, 30 mg m(-3)/24 h or 50 mg m(-3)/12 h (p>0.05). The results could be explained by the increases in the content of reduced form of glutathione (GSH), total glutathione (TGSH), ascorbate (AsA), ratio of GSH/GSSG (oxidized form of glutathione), activities of ascorbate peroxidase (APX), glutathione peroxidase (GPX), glutathione reductase (GR) and glutathione S-transferases (GST). On the other hand, exposure to higher doses of SO2 and longer exposure times, the values of the GSH-AsA dependent antioxidative indices decreased significantly (p<0.01), manifested by increased levels of H2O2. Furthermore, the levels of H2O2, MDA and RC varied little when SO2 doses and exposure times reached a 'critical' value (50 mg m(-3)/24 h). The defense ability of T. erecta to SO2 reached nearly extremity. To summarize, the response of T. erecta to elevated SO2 was related to higher H2O2 levels. GSH-AsA dependent detoxification pathway played an important role in against SO2-induced toxicity, although the defense response could not sufficiently alleviate oxidative damage when SO2 doses and exposure times reached critical value., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Edible flowers are commonly used in human nutrition and their consumption has increased in recent years. The aim of this study was to ascertain the nutritional composition and the content and profile of phenolic compounds of three edible flowers, monks cress (Tropaeolum majus), marigold (Tagetes erecta) and paracress (Spilanthes oleracea), and to determine the relationship between the presence of phenolic compounds and the antioxidant capacity. Proximate composition, total dietary fibre (TDF) and minerals were analysed according to official methods: total phenolic compounds (TPC) were determined with Folin-Ciocalteu's reagent, whereas antioxidant capacity was evaluated using Trolox Equivalent Antioxidant Capacity (TEAC) and Oxygen Radical Absorbance Capacity (ORAC) assays. In addition, phenolic compounds were characterised by HPLC-DAD-MSn. In relation to the nutritional value, the edible flowers had a composition similar to that of other plant foods, with a high water and TDF content, low protein content and very low proportion of total fat-showing significant differences among samples. The levels of TPC compounds and the antioxidant capacity were significantly higher in T. erecta, followed by S. oleracea and T. majus. Thirty-nine different phenolic compounds were tentatively identified, with flavonols being the major compounds detected in all samples, followed by anthocyanins and hydroxycynnamic acid derivatives. In T. erecta small proportions of gallotannin and ellagic acid were also identified.

Tannery sludge is available in plenty and is hazardous to environment as well as plant and animal life. It is very important to manage the tannery sludge in an environmentally sound manner. The aim of this study was to assess the physico-chemical, microbial and biochemical properties of soil treated with different levels of sludge. In this study, Tagetes minuta an essential oil bearing crop was grown in two different textured soils treated with different levels of tannery sludge. Application of tannery sludge (TS) increased the growth and oil yield of plant and also the activity of urease and soil microbial biomass nitrogen (SMBN) when applied in 50:50 combinations of soil:sludge. The crop performed well in coarse soil with a soil:sludge ratio of 50:50. High concentration of tannery sludge exhibited inhibitory effect on SMBN and urease activity. Acid/alkaline phosphatase, dehydrogenase and soil microbial biomass carbon (SMBC) increased as the sludge concentration increased in soil. This may be due to high organic matter present in tannery sludge. Roots accumulated more metal than the shoot. No detectable amount of metal was found in oil of T.minuta. To test the relation between 20 characters principal component analysis (PCA) was performed. PCA analysis indicates that cation exchange capacity (CEC), SMBC, dehydrogenase, acid and alkaline phosphatases were grouped in group 1. SMBN, urease and cis-ocimene content in oil were in group 2 whereas biomasss, chlorophyll a, limonene, Z and E-tagetone were in group 3. PC-I contributes 54% of total variance and PC-II contributes 38% of the total variance. The results concluded that T.minuta can mitigate metal toxicity by root absorption. Microbial activity and biomass of plant was higher in coarse soil with TS than fine soil with TS., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Understanding allelopathy has been hindered by the lack of methods available to monitor the dynamics of allelochemicals in the soil. Previous work has demonstrated the feasibility of using polydimethylsiloxane (PDMS) microtubing (silicone tubing microextraction, or STME) to construct sampling devices to monitor the release of lipophilic allelochemicals from plant roots. The objective of this study was to use such sampling devices to intensively monitor thiophene fluxes beneath marigolds over several weeks to gain insight into the magnitude of temporal and spatial heterogeneity in these fluxes. Marigolds were grown in rhizoboxes (20.5 x 20.5 x 3.0 cm) with 16 individual STME samplers per box. Thiophene sampling and HPLC analysis began 45 days after planting. At the end of the study, roots around each sampler were analyzed by HPLC. Results confirmed the tremendous spatial and temporal heterogeneity in thiophene production seen in our previous studies. STME probes show that thiophene concentrations generally increase over time; however, these effects were sampling-port specific. When sampling ports were monitored at 12 h intervals, fluxes at each port ranged from 0 to 2,510 ng day(-1). Fluxes measured over daylight hr averaged 29 % higher than those measured overnight. Fluxes were less than 1 % on average of the total thiophene content of surrounding roots. While the importance of such heterogeneity, or "patchiness", in the root zone has been recognized for soil nutrients, the potential importance in allelopathic interactions has seldom been considered. The reasons for this variability are unclear, but are being investigated. Our results demonstrate that STME can be used as a tool to provide a more finely-resolved picture of allelochemical dynamics in the root zone than has previously been available.

Tagetes erecta has a high potential for cadmium (Cd) phytoremediation. Through several hydroponic experiments, characteristics of (108)Cd distribution and accumulation were investigated in T. erecta with split -roots or removed xylem/phloem. The results showed that (108)Cd transport from roots to aboveground tissues showed the homolateral transport phenomenon in split-root seedlings. (108)Cd content of leaves on the +(108)Cd side and the -(108)Cd side was not significantly different, which implied that there was horizontal transport of (108)Cd from the +(108)Cd side to the -(108)Cd side in cut-root seedlings. Like (108)Cd transport, the transport of (70)Zn was homolateral. Reduction of water consumption in the removed xylem treatment significantly decreased (108)Cd accumulation; whereas, the removed phloem treatment had no significant effect on water consumption, but did decrease (108)Cd accumulation in leaves of the seedlings. The removal of phloem significantly reduced distal leaf (108)Cd content, which was significantly lower than that in the basal leaves in both the split-root and unsplit-root seedlings. Overall, the results presented in this study revealed that the root to aboveground cadmium translocation via phloem is as an important and common physiological process as xylem determination of the cadmium accumulation in stems and leaves of marigold seedlings., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Tagetes patula is an annual flowering plant belonging to family Asteraceae. The present study deals with in vitro decolorization and remediation of a textile dye Reactive Blue 160 by T. patula. There was considerable (∼90%) decolorization of the dye within 4d of incubation, as confirmed by UV-vis, HPLC and FTIR analysis. The enzymes responsible for the remediation were lignin peroxidase, tyrosinase, laccase and NADH-DCIP reductase which were found in root tissues of the plantlets. GC-MS analysis of the products revealed formation of six metabolites such as sodium benzenesulfonate, 6-chloro 1,3,5-triazine-2,4-diamine, disodium benzene-1,4-disulfonate, sodium 3-amino-4-hydroxybenzenesulfonate, 1-phenylmethanediamine and sodium 4-amino-3-carboxybenzenesulfonate after phytoremediation of Reactive Blue 160. Based on the FTIR and GC-MS results, the possible pathway for the biodegradation of Reactive Blue 160 has been traced. The non-toxic nature of the degraded products was confirmed by performing cytogenotoxicity tests on root tip cells of growing Allium cepa., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

The present study was conducted to investigate the effectiveness of GA(3) and Tween-80 on enhancing the phytoremediation of Cd-B[a]P co-contaminated soils. Results showed that the addition of GA(3) and GA(3)-Tween-80 enhanced Tagetes patula growth by 14%-32% and 23%-55%, respectively, relative to the control group. However, under independent GA(3)-treated soils, Cd and B[a]P concentrations in the shoots of the plants decreased by 15%-33% and 15%-53%, respectively, compared with CK. By contrast, the shoot concentration and accumulation of Cd under GA(3)-Tween-80 treatment increased by 0.01-0.46 and 1.33-1.55 times, respectively, whereas those of B[a]P increased from 0.57 to 0.82, and 1.33 to 1.55 times, respectively, compared with those of the control. Optimal result for Cd phytoextraction was obtained under combined 5 mmol Tween-80 kg(-1) and 1 mmol GA(3) kg(-1) treatment, and the maximum removal rate of B[a]P was obtained after the application of 5 mmol Tween-80 kg(-1) and 5 mmol GA(3) kg(-1)., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Drought stress is one of the most important environmental factors that regulates plant growth and development. In this study, we examined the effects of nitric oxide (NO) and hydrogen peroxide (H(2)O(2)) on adventitious rooting in marigold (Tagetes erecta L.) under drought stress. The results showed that the promoting effect of NO or H(2)O(2) on rooting under drought stress was dose-dependent, with a maximal biological response at 10 μM NO donor sodium nitroprusside (SNP) or 600 μM H(2)O(2). Results also indicated that endogenous NO and H(2)O(2) may play crucial roles in rooting under drought conditions, and H(2)O(2) may be involved in rooting promoted by NO under drought stress. NO or H(2)O(2) treatment attenuated the destruction of mesophyll cells ultrastructure by drought stress. Similarly, NO or H(2)O(2) increased leaf chlorophyll content, chlorophyll fluorescence parameters (Fv/Fm, ΦPS II and qP), and hypocotyls soluble carbohydrate and protein content, while decreasing starch content. Results suggest that the protection of mesophyll cells ultrastructure by NO or H(2)O(2) under drought conditions improves the photosynthetic performance of leaves and alleviates the negative effects of drought on carbohydrate and nitrogen accumulation in explants, thereby adventitious rooting being promoted., (Copyright © 2012 Elsevier Masson SAS. All rights reserved.)

Phytoremediation is an environmental biotechnology that seeks to remediate pollution caused by bioaccumulative toxins like copper (Cu). Symbiotic mycorrhizal associations can increase the uptake and delivery of low mobility nutrients and micronutrients to the host plant because they solubilize these substances and increase their catchment area. To analyze the effect of mycorrhizae on the phytoaccumulation of Cu, we studied their ability to solubilize Cu(II) and enhance its absorption by the plant Tagetes erecta L. colonized with the arbuscular mycorrhizal fungus Glomus intraradices. Plants were grown for nine weeks in a growth chamber under controlled conditions of temperature, relative humidity and photoperiod. Cu was added in the insoluble form of CuO to simulate the insoluble Cu-O affixed species in soil. The biotic and abiotic parameters of colonization, foliar area, biomass and the pH of leachates were determined as functions of the Cu concentration that was measured in the roots, shoots and leachates by AAS. The results of Cu absorption showed that the colonized plants accumulated more Cu in the roots as well as the whole plant and that both the colonized and non-colonized plants displayed the typical behavior of Cu excluders. Mycorrhizal colonization of the roots resulted in a proliferation of vesicles and this was observed to scale with root tissue Cu concentrations. Also, the G. intraradices-T. erecta system displayed a higher resistance to the toxicity induced by Cu while nonetheless improving the indices of phytoaccumulative yields. These results suggest that G. intraradices possibly accumulates Cu in its vesicles thereby enhancing the Cu tolerance of T. erecta even while increasing root Cu accumulation. The parameters of bioconcentration factor and translocation factor measured in this work suggest that the system T. erecta-G. intraradices can potentially phytostabilize Cu in contaminated soils., (Copyright © 2011 Elsevier B.V. All rights reserved.)

By the methods of principal component analysis, subordinate function, and cluster analysis, a comprehensive evaluation was conducted on the drought-resistance of 16 physiological indices of nine marigold cultivars. Under drought stress, the 16 physiological indices had different responses, among which, free proline (Pro), H2O2, and ascorbate peroxidase (APX) showed the greatest sensitivity. There existed significant correlations in the drought-resistance coefficients of parts of the physiological indices. Four principal factors presented 88.6% of the information of the 16 indices, and the cultivars 'Janie' and 'Gate gold', 'Bonanzn', 'Janie', and 'Chokdee' had the strongest drought-resistance for the 4 principal factors, respectively. The comprehensive evaluation value of the drought-resistance of the 9 cultivars was in the order of 'Janie' > 'Gate gold' > 'Bonanza' > 'Chokdee' > 'Giant' > 'Great hero' > 'Little hero' > 'Durango' > 'Discovery'. The 9 cultivars could be clustered into 3 groups, and 'Gate gold', 'Janie', 'Bonanza' and 'Chokdee' belonged to the drought-resistance group.

Pot-culture experiments were conducted to investigate the single effect of benzo[a]pyrene (B[a]P) and the joint effect of metal-B[a]P on the growth of Tagetes patula and its uptake, accumulation and dissipation of heavy metals and B[a]P. Results showed that the low concentration of B[a]P (≤10 mg kg(-1)) could facilitate plant growth and resulted in an increase in biomass at the rate of 10.0-49.7% relative to the control. There were significantly positive correlations between the concentrations of B[a]P accumulated in tissues of the plants and soil B[a]P (P<0.001). However, the occurrence of Cd, Cu and Pb had inhibitive effects on plant growth and B[a]P uptake and accumulation on the whole. T. patula still exhibited a steady feature of Cd-hyperaccumulator under combined contaminated soils. By contrast, the effectiveness of Cu and Pb absorption in the plants was very weak. Plant-promoted biodegradation of B[a]P was the dominant contribution, 79.2-92.4% and 78.2-92.9% of dissipation of B[a]P came from plant-biodegradation under single B[a]P and metal-B[a]P contaminated soils, respectively. Therefore, T. patula might be useful for phytoremediation of B[a]P and B[a]P-Cd contaminated sites., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Allelopathy, a phenomenon where compounds produced by one plant limit the growth of surrounding plants, is a controversially discussed factor in plant-plant interactions with great significance for plant community structure. Common mycorrhizal networks (CMNs) form belowground networks that interconnect multiple plant species; yet these networks are typically ignored in studies of allelopathy. We tested the hypothesis that CMNs facilitate transport of allelochemicals from supplier to target plants, thereby affecting allelopathic interactions. We analyzed accumulation of a model allelopathic substance, the herbicide imazamox, and two allelopathic thiophenes released from Tagetes tenuifolia roots, by diffusion through soil and CMNs. We also conducted bioassays to determine how the accumulated substances affected plant growth. All compounds accumulated to greater levels in target soils with CMNs as opposed to soils without CMNs. This increased accumulation was associated with reduced growth of target plants in soils with CMNs. Our results show that CMNs support transfer of allelochemicals from supplier to target plants and thus lead to allelochemical accumulation at levels that could not be reached by diffusion through soil alone. We conclude that CMNs expand the bioactive zones of allelochemicals in natural environments, with significant implications for interspecies chemical interactions in plant communities.

Phytoextraction is an emerging cost-effective solution for remediation of contaminated soils which involves the removal of toxins, especially heavy metals and metalloids, by the roots of the plants with subsequent transport to aerial plant organs. The aim of the present investigation is to study the effects of EDTA and citric acid on accumulation potential of marigold (Tagetes erecta) to Zn, Cu, Pb, and Cd and also to evaluate the impacts of these chelators (EDTA and citric acid) in combination with all the four heavy metals on the growth of marigold. The plants were grown in pots and treated with Zn (7.3 mg l(-1)), Cu (7.5 mg I(-1)), Pb (3.7 mg l(-1)) and Cd (0.2 mg l(-1)) alone and in combination with different doses of EDTA i.e., 10, 20 and 30 mg l(-1). All the three doses of EDTA i.e., 10, 20 and 30 mg l(-1) significantly increased the accumulation of Zn, Cu, Pb and Cd by roots, stems and leaves as compared to control treatments. The 30 mg l(-1) concentration of citric acid showed reduced accumulation of these metals by root, stem and leaves as compared to lower doses i.e., 10 and 20 mg l(-1). Among the four heavy metals, Zn accumulated in the great amount (526.34 mg kg(-1) DW) followed by Cu (443.14 mg kg(-1) DW), Pb (393.16 mg kg(-1) DW) and Cd (333.62 mg kg(-1) DW) in leaves with 30 mg l(-1) EDTA treatment. The highest concentration of EDTA and citric acid (30 mg l(-1)) caused significant reduction in growth of marigold in terms of plant height, fresh weight of plant, total chlorophyll, carbohydrate content and protein content. Thus EDTA and citric acid efficiently increased the phytoextractability of marigold which can be used to remediate the soil contaminated with these metals.

Marigold (Tagetes erecta) is an Asteraceous plant of industrial, ornamental and medicinal importance. Tagetes erecta species, popularly known as marigold, is grown as ornamental plant and is adapted to several agro climates. Inflorescences have been utilized as pigment source for food coloring, mainly of poultry skin and eggs. Lutein is the main pigment in marigold flowers. Some carotenoids are well known as provitamin A compounds. There are many reports on carotenoids and their effect on the prevention of certain ocular diseases, ischemic heart disease, strokes, photoprotection, immune response, aging and cancer. Marigold flowers are certainly a good source of carotenoids; they show very different pigmentation levels. This chapter describes the establishment of techniques for plant regeneration, gene expression, pigment extraction and pigment deposition in specific structures of marigold.

The difficulties of monitoring allelochemical concentrations in soil and their dynamics over time have been a major barrier to testing hypotheses of allelopathic effects. Here, we evaluate three diffusive sampling strategies that employ polydimethylsiloxane (PDMS) sorbents to map the spatial distribution and temporal dynamics of root-exuded thiophenes from the African marigold, Tagetes erecta. Solid phase root zone extraction (SPRE) probes constructed by inserting stainless steel wire into PDMS tubing were used to monitor thiophene concentrations at various depths beneath marigolds growing in PVC pipes. PDMS sheets were used to map the distribution of thiophenes beneath marigolds grown in thin glass boxes. Concentrations of the two major marigold thiophenes measured by these two methods were extremely variable in both space and time. Dissection and analysis of roots indicated that distribution of thiophenes in marigold roots also was quite variable. A third approach used 1 m lengths of PDMS microtubing placed in marigold soil for repeated sampling of soil without disturbance of the roots. The two ends of the tubing remained out of the soil so that solvent could be washed through the tubing to collect samples for HPLC analysis. Unlike the other two methods, initial experiments with this approach show more uniformity of response, and suggest that soil concentrations of marigold thiophenes are affected greatly even by minimal disturbance of the soil. Silicone tube microextraction gave a linear response for alpha-terthienyl when maintained in soils spiked with 0-10 ppm of this thiophene. This method, which is experimentally simple and uses inexpensive materials, should be broadly applicable to the measurement of non-polar root exudates, and thus provides a means to test hypotheses about the role of root exudates in plant-plant and other interactions.

Tagetes patula L. (Marigold) hairy roots were selected among few hairy root cultures from other plants tested for the decolorization of Reactive Red 198. Hairy roots of Tagetes were able to remove dye concentrations up to 110 mg L(-l) and could be successively used at least for five consecutive decolorization cycles. The hairy roots of Tagetes decolorized six different dyes, viz. Golden Yellow HER, Methyl Orange, Orange M2RL, Navy Blue HE2R, Reactive Red M5B and Reactive Red 198. Significant induction of the activity of biotransformation enzymes indicated their crucial role in the dye metabolism. UV-vis spectroscopy, HPLC and FTIR spectroscopy analyses confirmed the degradation of Reactive Red 198. A possible pathway for the biodegradation of Reactive Red 198 has been proposed with the help of GC-MS and metabolites identified as 2-aminonaphthol, p-aminovinylsulfone ethyl disulfate and 1-aminotriazine, 3-pyridine sulfonic acid. The phytotoxicity study demonstrated the non-toxic nature of the extracted metabolites. The use of such hairy root cultures with a high ability for bioremediation of dyes is discussed.