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1.
Ecotoxicol Environ Saf ; 202: 110851, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32673966

RESUMO

Arsenic is a harmful and toxic substance to the growth and development of plants. Salicylic acid (SA) acts as a signaling molecule, plays pivotal roles in the overall growth and development of plants under various environmental stresses. Artemisinin extracted from the leaves of A. annua helps in malarial treatment. The present investigation is aimed to find out the possible ameliorative role of exogenously-applied salicylic acid (SA) on two varieties of Artemisia annua L., namely 'CIM-Arogya' and 'Jeevan Raksha' under arsenic (As) stress conditions. For this, growth, physiological and biochemical characterization, and artemisinin production was assessed. The various treatments applied on the plants were Control, 10-6 M SA, 10-5 M SA, 45 mg kg-1As, 45 mg kg-1 As + 10-6 M SA, and 45 mg kg-1 As + 10-5 M SA. Arsenic at 45 mg kg-1 of soil, reducing the overall performance of both varieties at 90 and 120 DAP. However, the levels of antioxidants were enhanced in As-stressed plants, and the supplementation of SA further increased these antioxidants in SA-treated plants. It has been observed that minimum reduction in growth and yield occurs with enhanced production of artemisinin in the case of 'CIM-Arogya' compared to 'Jeevan Raksha' under As stress (45 mg kg-1 of soil). Leaf-applied SA significantly increased the content (49.0% & 43.4%) and yield (53.3% & 46.3%) of artemisinin in both tolerant and sensitive varieties as compared to their respective controls. Thus, the variety 'CIM-Arogya' showed tolerant behavior over 'Jeevan Raksha' and is much adapted to higher As stress.


Assuntos
Arsênico/toxicidade , Artemisia annua/fisiologia , Poluentes do Solo/toxicidade , Antioxidantes/metabolismo , Artemisia annua/crescimento & desenvolvimento , Artemisia annua/metabolismo , Artemisininas , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Estresse Oxidativo , Folhas de Planta/metabolismo , Ácido Salicílico/farmacologia , Solo , Estresse Fisiológico/efeitos dos fármacos
2.
PLoS One ; 15(6): e0234410, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32516341

RESUMO

The Eupatorium adenophorum have widespread invaded the karst ecosystem of southwest China and threatened the regional native community stability. Arbuscular mycorrhizae (AM) plays an important role in promoting growth for host plants via root external mycelia. However, whether AM regulates plant root traits underlying competition between invasive and native species via mycorrhizal networks in karst habitats, remains unclear. An experiment was conducted in a microcosm composed of two planting compartments flanking a competition compartment. The invasive E. adenophorum and native Artemisia annua were each placed in one of the two planting compartments with or without Glomus etunicatum fungus. The nutrient access treatments included the competitive utilization (Cu), single utilization (Su) and non-utilization (Nu) by using different nylon meshes allowed or prevented mycelium passing to acquire nutrients from the competition compartment. Root traits and nutrients of the two species were analyzed. The results showed that AM fungi had differential effects on root traits and nutrients of E. adenophorum and A. annua seedlings, which increased dry weight, length, surface area, volume, tips and branching points in roots, specific root length and volume, root nitrogen (N) and phosphorus (P) contents under Cu, Su and Nu treatments. AM fungus was also associated with decreases in the average diameter for both species. Under the Cu treatment, E. adenophorum had significantly greater length, surface area, volume, tips and branching points of roots, specific root traits, and root N and P than A. annua. AM fungi changed root phenotypes and nutrient uptake for both invasive and native plant species via interconnected mycorrhizal networks. Overall, our results suggest that through mycorrhizal networks, the invasive plant experiences greater benefits than the native plant in the nutrient competition, which fosters root morphological developments in karst soil.


Assuntos
Ageratina/metabolismo , Micorrizas/metabolismo , Microbiologia do Solo , Artemisia annua/metabolismo , China , Ecossistema , Micélio , Micorrizas/fisiologia , Nitrogênio , Nutrientes , Fósforo , Raízes de Plantas/crescimento & desenvolvimento , Plantas Daninhas/metabolismo , Solo , Árvores/crescimento & desenvolvimento
3.
Trends Plant Sci ; 25(5): 466-476, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32304658

RESUMO

Plants regulate the synthesis of specialized compounds through the actions of individual transcription factors (TFs) or sets of TFs. One such compound, artemisinin from Artemisia annua, is widely used as a pharmacological product in the first-line treatment of malaria. However, the emergence of resistance to artemisinin in Plasmodium species, as well as its low production rates, have required innovative treatments such as exploiting the synergistic effects of flavonoids with artemisinin. We overview current knowledge about flavonoid and artemisinin transcriptional regulation in A. annua, and review the dual action of TFs and structural genes that can regulate both pathways simultaneously. Understanding the concerted action of these TFs and their associated structural genes can guide the development of strategies to further improve flavonoid and artemisinin production.


Assuntos
Artemisia annua , Artemisininas , Artemisia annua/genética , Artemisia annua/metabolismo , Artemisininas/metabolismo , Flavonoides , Regulação da Expressão Gênica , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
4.
Trends Plant Sci ; 25(5): 477-487, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31983619

RESUMO

Plant glandular trichomes are epidermal secretory structures producing various specialized metabolites. These metabolites are involved in plant adaptation to its environment and many of them have remarkable properties exploited by fragrance, flavor, and pharmaceutical industries. The identification of genes controlling glandular trichome development is of high interest to understand how plants produce specialized metabolites. Our knowledge about this developmental process is still limited, but genes controlling glandular trichome initiation and morphogenesis have recently been identified. In particular, R2R3-MYB and HD-ZIP IV transcription factors appear to play essential roles in glandular trichome initiation in Artemisia annua and tomato. In this review, we focus on the results obtained in these two species and we propose genetic regulation models integrating these data.


Assuntos
Artemisia annua , Lycopersicon esculentum , Artemisia annua/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Lycopersicon esculentum/genética , Lycopersicon esculentum/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Tricomas/genética
5.
Biochim Biophys Acta Gene Regul Mech ; 1863(6): 194429, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-31634636

RESUMO

Prediction of gene function and gene regulatory networks is one of the most active topics in bioinformatics. The accumulation of publicly available gene expression data for hundreds of plant species, together with advances in bioinformatical methods and affordable computing, sets ingenuity as one of the major bottlenecks in understanding gene function and regulation. Here, we show how a credit card-sized computer retailing for <50 USD can be used to rapidly predict gene function and infer regulatory networks from RNA sequencing data. To achieve this, we constructed a bioinformatical pipeline that downloads and allows quality-control of RNA sequencing data; and generates a gene co-expression network that can reveal enzymes and transcription factors participating and controlling a given biosynthetic pathway. We exemplify this by first identifying genes and transcription factors involved in the biosynthesis of secondary cell wall in the plant Artemisia annua, the main natural source of the anti-malarial drug artemisinin. Networks were then used to dissect the artemisinin biosynthesis pathway, which suggest potential transcription factors regulating artemisinin biosynthesis. We provide the source code of our pipeline (https://github.com/mutwil/LSTrAP-Lite) and envision that the ubiquity of affordable computing, availability of biological data and increased bioinformatical training of biologists will transform the field of bioinformatics. This article is part of a Special Issue entitled: Transcriptional Profiles and Regulatory Gene Networks edited by Dr. Dr. Federico Manuel Giorgi and Dr. Shaun Mahony.


Assuntos
Artemisia annua/genética , Regulação da Expressão Gênica de Plantas , Redes Reguladoras de Genes , Microcomputadores , RNA-Seq , Antimaláricos/metabolismo , Artemisia annua/metabolismo , Artemisininas/metabolismo , Vias Biossintéticas/genética , Parede Celular/metabolismo
6.
Plant Cell Rep ; 39(1): 101-117, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31576412

RESUMO

KEY MESSAGE: Blue and yellow light affected metabolism and the morphology. Blue and red promote the DOXP/MEP pathway. ADS gene expression was increased in plants cultivated under blue, promoting artemisinin content. Artemisinin-based combination therapies are the most effective treatment for highly lethal malaria. Artemisinin is produced in small quantities in the glandular trichomes of Artemisia annua L. Our aim was to evaluate the effect of light quality in A. annua cultivated in vitro under different light qualities, considering anatomical and morphological changes, the volatile composition, artemisinin content and the expression of two key enzymes for artemisinin biosynthesis. Yellow light is related to the increase in the number of glandular trichomes and this seemed to positively affect the molecular diversity in A. annua. Yellow light-stimulated glandular trichome frequency without triggered area enhancement, whereas blue light stimulated both parameters. Blue light enhanced the thickness of the leaf epidermis. The B-promoting effect was due to increased cell size and not to increased cell numbers. Green and yellow light positively influenced the volatile diversity in the plantlets. Nevertheless, blue and red light seemed to promote the DOXP/MEP pathway, while red light stimulates MVA pathway. Amorpha-4,11-diene synthase gene expression was significantly increased in plants cultivated under blue light, and not red light, promoting artemisinin content. Our results showed that light quality, more specifically blue and yellow light, positively affected secondary metabolism and the morphology of plantlets. It seemed that steps prior to the last one in the artemisinin biosynthesis pathway could be strongly influenced by blue light. Our work provides an alternative method to increase the amount of artemisinin production in A. annua without the use of transgenic plants, by the employment of blue light.


Assuntos
Artemisia annua/metabolismo , Artemisininas/metabolismo , Folhas de Planta/química , Folhas de Planta/metabolismo , Artemisininas/isolamento & purificação , Vias Biossintéticas , Regulação da Expressão Gênica de Plantas , Luz , Folhas de Planta/ultraestrutura , Proteínas de Plantas/genética , Metabolismo Secundário , Tricomas/metabolismo
7.
J Photochem Photobiol B ; 202: 111652, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31760374

RESUMO

The Biocompatibility and stability of nanoparticles using plants have been widely investigated due to its applications in the biomedical industry. Currently, there is a growing interest in nanoparticles in bone remodelling. Artemisia annua is an herbal plant commonly used in the treatment of various ailments. This study investigated the zinc oxide nanoparticles (ZnO NPs) using the green synthesis technique from A. annua and the effects of A. annua ZnO-NPs on osteoblast differentiation and inhibition of osteoclast formation. The formulated ZnO-NPs from A. annua were characterized by using various spectroscopic and microscopic methods Fourier transform-infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), X-ray diffraction (XRD), and UV-Visible spectroscopy. The disc diffusion method was adopted to test the antimicrobial efficacy of ZnO-NPs. The viability of MG-63 cells were assayed by MTT test and Osteogenic-related assays like Real-time PCR and Mineralization assay were adopted to determine the effects of A. annua ZnO-NPs on the multiplication and differentiation of human osteoblast-like MG-63 cells. The characterization of A. annua ZnO-NPs revealed the crystalline nature with high zinc content and the presence of bioactive compounds from A. annua extract. The synthesized A. annua ZnO-NPs indicate significant antimicrobial potential. Besides, A. annua ZnO-NPs enhanced the proliferation, differentiation, and mineralization without causing significant cytotoxic impact on MG-63 cells. These effects indicate that A. annua ZnO-NPs can both stimulate bone formation via the differentiation of MG-63 cells. Hence, it was concluded that A. annua ZnO-NPs can be a promising agent for the treatment of bone deformities and bone-related diseases, however further research also required to explore the clear mechanism of A. annua ZnO-NPs in the formation and differentiation of MG-63 cells.


Assuntos
Artemisia annua/química , Diferenciação Celular , Proliferação de Células , Nanopartículas Metálicas/química , Anti-Infecciosos/síntese química , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Artemisia annua/metabolismo , Cálcio/metabolismo , Candida/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Química Verde , Humanos , Nanopartículas Metálicas/toxicidade , Osteoblastos/citologia , Osteoblastos/metabolismo , Osteogênese/efeitos dos fármacos , Casca de Planta/química , Casca de Planta/metabolismo , Extratos Vegetais/química , Óxido de Zinco/química
8.
Plant Cell Physiol ; 60(12): 2826-2836, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31504880

RESUMO

In Artemisia annua plants, glandular trichomes (GTs) are responsible for the biosynthesis and secretion of sesquiterpene lactones including artemisinin/arteannuin B. Nonspecific lipid transfer proteins (LTPs) in plants bind and carry lipid molecules across the cell membrane and are also known as secretary proteins. Interestingly, the transcripts of LTP genes are exceptionally abundant in the GTs of A. annua. In the present study, we isolated two trichome-specific LTP genes (AaLTP3 and AaLTP4) from a Korean ecotype of A. annua. AaLTP3 was expressed abundantly in shoots, whereas AaLTP4 was expressed in flowers. The GUS signal driven by the AaLTP3 or AaLTP4 promoter in transgenic A. annua plants revealed that the AaLTP3 promoter was active on hair-like non-GTs and that the AaLTP4 promoter was active on GTs. Analysis of enhanced cyan fluorescent protein (ECFP) fluorescence fused with the AaLTP3 or AaLTP4 protein in transgenic tobacco revealed that ECFP florescence was very bright on secreted lipids of long GTs. Moreover, the florescence was also bright on the head cells of short trichomes and their secreted granules. Immunoblotting analysis of GT exudates in petioles of A. annua revealed a strong positive signal against the AaLTP4 antibody. Overexpression of AaLTP3 or AaLTP4 in transgenic A. annua plants resulted in enhanced production of sesquiterpene lactones (arteannuin B, artemisinin, dihydroartemisinic acid and artemisinic acid) compared with those of wild type. The present study shows that LTP genes (AaLTP3 or AaLTP4) play important roles in the sequestration and secretion of lipids in GTs of A. annua, which is useful for the enhanced production of sesquiterpene lactones by genetic engineering.


Assuntos
Artemisia annua/metabolismo , Lactonas/metabolismo , Sesquiterpenos/metabolismo , Tricomas/genética , Artemisia annua/genética , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Regiões Promotoras Genéticas/genética
9.
J Exp Bot ; 70(18): 4835-4848, 2019 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-31087059

RESUMO

Basic helix-loop-helix (bHLH) proteins are the second largest family of transcription factors (TFs) involved in developmental and physiological processes in plants. In this study, 205 putative bHLH TF genes were identified in the genome of Artemisia annua and expression of 122 of these was determined from transcriptomes used to construct the genetic map of A. annua. Analysis of gene expression association allowed division of the 122 bHLH TFs into five groups. Group V, containing 15 members, was tightly associated with artemisinin biosynthesis genes. Phylogenetic analysis indicated that two bHLH TFs, AabHLH106 and AabHLH112, were clustered with Arabidopsis ICE proteins. AabHLH112 was induced by low temperature, while AabHLH106 was not. We therefore chose AabHLH112 for further examination. AabHLH112 was highly expressed in glandular secretory trichomes, flower buds, and leaves. Dual-luciferase assays demonstrated that AabHLH112 enhanced the promoter activity of artemisinin biosynthesis genes and AaERF1, an AP2/ERF TF that directly and positively regulates artemisinin biosynthesis genes. Yeast one-hybrid assays indicated that AabHLH112 could bind to the AaERF1 promoter, but not to the promoters of artemisinin biosynthesis genes. Overexpression of AabHLH112 significantly up-regulated the expression levels of AaERF1 and artemisinin biosynthesis genes and consequently promoted artemisinin production.


Assuntos
Artemisia annua/genética , Artemisininas/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Terminação de Peptídeos/genética , Proteínas de Plantas/genética , Artemisia annua/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Temperatura Baixa , Flores/metabolismo , Perfilação da Expressão Gênica , Fatores de Terminação de Peptídeos/metabolismo , Filogenia , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Tricomas/metabolismo
10.
Plant Cell Physiol ; 60(8): 1747-1760, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31076768

RESUMO

Artemisinin, the frontline drug against malaria, is a sesquiterpenoid extracted from Artemisia annua. Light has been proposed to play an important role in the activation of artemisinin biosynthesis. Here, we report the basic leucine zipper transcription factor (TF) AaHY5 as a key regulator of light-induced biosynthesis of artemisinin. We show that AaHY5 transcription overlaps with that of artemisinin biosynthesis genes in response to light and in A. annua tissues. Analysis of AaHY5 overexpression and RNAi-suppression lines suggests that AaHY5 is a positive regulator of the expression of artemisinin biosynthesis genes and accumulation of artemisinin. We show that AaHY5 complements the hy5 mutant in Arabidopsis thaliana. Our data further suggest that AaHY5 interacts with AaCOP1, the ubiquitin E3 ligase CONSTITUTIVE PHOTOMORPHOGENIC1 in A. annua. In yeast one-hybrid and transient expression assays, we demonstrate that AaHY5 acts via the TF GLANDULAR TRICHOME-SPECIFIC WRKY 1 (AaGSW1) in artemisinin regulation. In summary, we present a novel regulator of artemisinin gene expression and propose a model in which AaHY5 indirectly controls artemisinin production in response to changing light conditions.


Assuntos
Artemisia annua/metabolismo , Artemisininas/metabolismo , Luz , Artemisia annua/efeitos da radiação , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Plantas Geneticamente Modificadas/efeitos da radiação , Fatores de Transcrição
11.
Plant Mol Biol ; 100(4-5): 527-541, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31093899

RESUMO

KEY MESSAGE: A class III peroxidase from Artemisia annua has been shown to indicate the possibility of cellular localization-based role diversity, which may have implications in artemisinin catabolism as well as lignification. Artemisia annua derives its importance from the antimalarial artemisinin. The -O-O- linkage in artemisinin makes peroxidases relevant to its metabolism. Earlier, we identified three peroxidase-coding genes from A. annua, whereby Aa547 showed higher expression in the low-artemisinin plant stage whereas Aa528 and Aa540 showed higher expression in the artemisinin-rich plant stage. Here we carried out tertiary structure homology modelling of the peroxidases for docking studies. Maximum binding affinity for artemisinin was shown by Aa547. Further, Aa547 showed greater binding affinity for post-artemisinin metabolite, deoxyartemisinin, as compared to pre-artemisinin metabolites (dihydroartemisinic hydroperoxide, artemisinic acid, dihydroartemisinic acid). It also showed significant binding affinity for the monolignol, coniferyl alcohol. Moreover, Aa547 expression was related inversely to artemisinin content and directly to total lignin content as indicated by its transient silencing and overexpression in A. annua. Artemisinin reduction assay also indicated inverse relationship between Aa547 expression and artemisinin content. Subcellular localization using GFP fusion suggested that Aa547 is peroxisomal. Nevertheless, dual localization (intracellular/extracellular) of Aa547 could not be ruled out due to its effect on both, artemisinin and lignin. Taken together, this indicates possibility of localization-based role diversity for Aa547, which may have implications in artemisinin catabolism as well as lignification in A. annua.


Assuntos
Artemisia annua/enzimologia , Artemisininas/metabolismo , Peroxidase/fisiologia , Proteínas de Plantas/fisiologia , Artemisia annua/genética , Artemisia annua/metabolismo , Artemisininas/química , Redes e Vias Metabólicas , Modelos Moleculares , Peroxidase/genética , Peroxidase/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Interferência de RNA
12.
J Exp Bot ; 70(15): 3969-3979, 2019 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-31120500

RESUMO

Artemisinin is a sesquiterpene lactone produced by the Chinese traditional herb Artemisia annua and is used for the treatment of malaria. It is known that salicylic acid (SA) can enhance artemisinin content but the mechanism by which it does so is not known. In this study, we systematically investigated a basic leucine zipper family transcription factor, AaTGA6, involved in SA signaling to regulate artemisinin biosynthesis. We found specific in vivo and in vitro binding of the AaTGA6 protein to a 'TGACG' element in the AaERF1 promoter. Moreover, we demonstrated that AaNPR1 can interact with AaTGA6 and enhance its DNA-binding activity to its cognate promoter element 'TGACG' in the promoter of AaERF1, thus enhancing artemisinin biosynthesis. The artemisinin contents in AaTGA6-overexpressing and RNAi transgenic plants were increased by 90-120% and decreased by 20-60%, respectively, indicating that AaTGA6 plays a positive role in artemisinin biosynthesis. Importantly, heterodimerization with AaTGA3 significantly inhibits the DNA-binding activity of AaTGA6 and plays a negative role in target gene activation. In conclusion, we demonstrate that binding of AaTGA6 to the promoter of the artemisinin-regulatory gene AaERF1 is enhanced by AaNPR1 and inhibited by AaTGA3. Based on these findings, AaTGA6 has potential value in the genetic engineering of artemisinin production.


Assuntos
Artemisia annua/metabolismo , Artemisininas/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Proteínas de Plantas/metabolismo , Ácido Salicílico/metabolismo , Artemisia annua/genética , Fatores de Transcrição de Zíper de Leucina Básica/genética , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Proteínas de Plantas/genética
13.
Mol Plant ; 12(5): 704-714, 2019 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-30851440

RESUMO

Artemisinin-based combination therapy (ACT) forms the first line of malaria treatment. However, the yield fluctuation of artemisinin has remained an unsolved problem in meeting the global demand for ACT. This problem is mainly caused by the glandular trichome (GT)-specific biosynthesis of artemisinin in all currently used Artemisia annua cultivars. Here, we report that non-GT cells of self-pollinated inbred A. annua plants can express the artemisinin biosynthetic pathway. Gene expression analysis demonstrated the transcription of six known pathway genes in GT-free leaves and calli of inbred A. annua plants. LC-qTOF-MS/MS analysis showed that these two types of GT-free materials produce artemisinin, artemisinic acid, and arteannuin B. Detailed IR-MALDESI image profiling revealed that these three metabolites and dihydroartemisinin are localized in non-GT cells of leaves of inbred A. annua plants. Moreover, we employed all the above approaches to examine artemisinin biosynthesis in the reported A. annua glandless (gl) mutant. The resulting data demonstrated that leaves of regenerated gl plantlets biosynthesize artemisinin. Collectively, these findings not only add new knowledge leading to a revision of the current dogma of artemisinin biosynthesis in A. annua but also may expedite innovation of novel metabolic engineering approaches for high and stable production of artemisinin in the future.


Assuntos
Artemisia annua/citologia , Artemisia annua/metabolismo , Artemisininas/metabolismo , Tricomas/metabolismo , Artemisia annua/genética , Artemisia annua/fisiologia , Engenharia Metabólica , Mutação , Polinização
14.
Biotechnol Appl Biochem ; 66(3): 369-375, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30719762

RESUMO

Artemisia annua is the only natural source of the sesquiterpenoid artemisinin, which is widely used to treat malaria. The phytohormone jasmonic acid (JA) can significantly promote artemisinin biosynthesis in A. annua. AabHLH1 can bind and activate artemisinin biosynthetic genes, such as AaADS and AaCYP71AV1. In this study, we proved that AabHLH1 was responsive to MeJA treatment and highly expressed in glandular trichome-enriched tissues, and that its expression profile was similar to that of AaADS. Yeast two-hybrid assays showed that AabHLH1 interacted with all nine AaJAZ proteins in A. annua. Functional analysis with transgenic plants showed that several artemisinin biosynthetic genes were upregulated in AabHLH1-OE transgenic A. annua lines and downregulated in AabHLH1-EAR lines; furthermore, the artemisinin content was increased in the AabHLH1-OE lines and decreased in the AabHLH1-EAR lines. These results demonstrate that the JA-induced AabHLH1 positively regulates artemisinin biosynthesis by regulating the biosynthetic genes, and thus provide new insight into the regulatory mechanism of JA-induced artemisinin biosynthesis in A. annua.


Assuntos
Artemisia annua/efeitos dos fármacos , Artemisininas/metabolismo , Ciclopentanos/farmacologia , Oxilipinas/farmacologia , Fatores de Transcrição/metabolismo , Artemisia annua/química , Artemisia annua/metabolismo , Artemisininas/química , Ciclopentanos/química , Oxilipinas/química , Tricomas/química , Tricomas/metabolismo
15.
Planta ; 249(2): 497-514, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30267151

RESUMO

MAIN CONCLUSION: UV-B-induced flavonoid biosynthesis is epigenetically regulated by site-specific demethylation of AaMYB1, AaMYC, and AaWRKY TF-binding sites inAaPAL1promoter-causing overexpression ofAaPALgene inArtemisia annua. The present study was undertaken to understand the epigenetic regulation of flavonoid biosynthesis under the influence of ultraviolet-B radiation using Artemisia annua L. as an experimental model. In-vitro propagated and acclimatized plantlets were treated with UV-B radiation (2.8 W m-2; 3 h), which resulted in enhanced accumulation of total flavonoid and phenolics content as well as eleven individual flavonoids measured through HPLC-DAC. Expression of eight genes (phenylanaline ammonia lyase, cinnamate-4-hydroxylase, 4-coumarate: CoA ligase; chalcone synthase, chalcone isomerase, cinnamoyl reductase, flavonoid-3'-hydroxylase, and flavones synthase) from upstream and downstream flavonoid biosynthetic pathways was measured through RT-PCR and RT-Q-PCR and all were variably induced under UV-B irradiation. Among them, AaPAL1 transcript and its protein were most significantly upregulated. Global DNA methylation analysis revealed hypomethylation of genomic DNA in A. annua. Further epigenetic characterization of promoter region of AaPAL1 revealed cytosine demethylation at five sites, which in turn caused epigenetic activation of six transcription factor-binding sites including QELEMENT, EBOXBNNAPA/MYCCONSENSUSAT, MYBCORE, MYBCOREATCYCB1, and GCCCORE. MYB transcription factors are positive regulators of flavonoid biosynthesis. Epigenetic activation of transcription-enhancing cis-regulatory elements in AaPAL1 promoter and subsequent overexpression of AaMYB1 and AaMYC and AaWRKY transcription factors under UV-B irradiation may probably be the reason for higher AaPAL1 expression and hence greater biosynthesis of flavonoids in A. annua L. The present study is the first report that provides mechanistic evidence of epigenetic regulation of flavonoid biosynthesis under UV-B radiation in A. annua L.


Assuntos
Artemisia annua/efeitos da radiação , Epigênese Genética , Flavonoides/metabolismo , Raios Ultravioleta , Aciltransferases/metabolismo , Artemisia annua/química , Artemisia annua/genética , Artemisia annua/metabolismo , Western Blotting , Cromatografia Líquida de Alta Pressão , Desmetilação do DNA/efeitos da radiação , Flavonoides/análise , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Liases/metabolismo , Redes e Vias Metabólicas , Regiões Promotoras Genéticas/genética , Reação em Cadeia da Polimerase em Tempo Real , Fatores de Transcrição/metabolismo , Transcriptoma
16.
Zhongguo Zhong Yao Za Zhi ; 43(20): 4169-4176, 2018 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-30486546

RESUMO

Artemisia annua also known as Qinghao, is a kind of traditional Chinese medicine. Its active ingredient is artemisinin, a sesquiterpene lactone compound with a peroxy bridging group structure. A. annua is an effective antimalarial drug. Artemisinin, a secondary metabolite in A. annua, can be induced by many physical and chemical factors, such as salinity, moisture, light, and plant hormones. Temperature, as an important growth factor, also has a great influence on the synthesis of artemisinin. This article aims to study the effect of high temperature on inducing artemisinin biosynthesis in A. annua. The A. annua seedlings were placed at 25, 40 °C, and the samples were taken after 0, 3, 12 and 36 h. The content of artemisinin in each sample was determined by liquid chromatography-mass spectrometry. Total RNA was extracted from the samples, and then transcriptome sequencing and real-time fluorescence quantitative PCR were used to quantitatively analyze the expression of the key enzyme genes in artemisinin synthesis pathway and competition pathway. The results showed that artemisinin content was increased by 20%, 42% and 68% after 3, 12, 36 h of treatment at 40 °C. The expression levels of FDS, ALDH1, CYP71AV1 and ADS were up-regulated by 4.3, 3.3, 2.5, 1.9 times, and the expression levels of SQS and BPS were down-regulated by 37% and 90% respectively. In summary, high temperature can promote the biosynthesis of artemisinin by promoting the expression of synthetase genes in artemisinin synthesis pathway and inhibiting the expression of synthetase genes in artemisinin-competition pathway.


Assuntos
Antimaláricos/metabolismo , Artemisia annua/metabolismo , Artemisininas/metabolismo , Temperatura , Vias Biossintéticas , Plantas Medicinais/metabolismo
17.
Sci Rep ; 8(1): 12659, 2018 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-30139985

RESUMO

Artemisinin, an effective anti-malarial drug is synthesized in the specialized 10-celled biseriate glandular trichomes of some Artemisia species. In order to have an insight into artemisinin biosynthesis in species other than A. annua, five species with different artemisinin contents were investigated for the expression of key genes that influence artemisinin content. The least relative expression of the examined terpene synthase genes accompanied with very low glandular trichome density (4 No. mm-2) and absence of artemisinin content in A. khorassanica (S2) underscored the vast metabolic capacity of glandular trichomes. A. deserti (S4) with artemisinin content of 5.13 mg g-1 DW had a very high expression of Aa-ALDH1 and Aa-CYP71AV1 and low expression of Aa-DBR2. It is possible to develop plants with high artemisinin synthesis ability by downregulating Aa-ORA in S4, which may result in the reduction of Aa-ALDH1 and Aa-CYP71AV1 genes expression and effectively change the metabolic flux to favor more of artemisinin production than artemisinic acid. Based on the results, the Aa-ABCG6 transporter may be involved in trichome development. S4 had high transcript levels and larger glandular trichomes (3.46 fold) than A. annua found in Iran (S1), which may be due to the presence of more 2C-DNA (3.48 fold) in S4 than S1.


Assuntos
Artemisia/metabolismo , Artemisininas/metabolismo , Alquil e Aril Transferases/genética , Alquil e Aril Transferases/metabolismo , Antimaláricos/metabolismo , Artemisia/enzimologia , Artemisia/genética , Artemisia annua/enzimologia , Artemisia annua/genética , Artemisia annua/metabolismo , Regulação da Expressão Gênica de Plantas , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/enzimologia , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Tricomas/genética , Tricomas/metabolismo
18.
Plant Physiol Biochem ; 130: 112-126, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29982168

RESUMO

To investigate on the effects of autopolyploidization on growth and artemisinin biosynthesis in Artemisia annua, we performed a comprehensive transcriptomic characterization of diploid and induced autotetraploid A. annua. The polyploidization treatment not only enhanced photosynthetic capacity and endogenous contents of indole-3-acetic acid (IAA), abscisic acid (ABA) and jasmonic acid (JA), oxidative stress, but increased the average level of artemisinin in tetraploids from 42.0 to 63.6%. The obvious phenotypic alterations in tetraploids were observed including shorter stems, larger size of stomata and glandular secretory trichomes (GSTs), larger leaves, more branches and roots. A total of 8763 (8.85%) differentially expressed genes (DEGs) were identified in autotetraploids and mainly involved in carbohydrate metabolic processes, cell wall organization and defense responses. Both the up-regulated expression of DNA methylation unigenes and enhanced level of DNA methylation in autotetraploids indicated a possible role of DNA methylation on transcriptomic remodeling and phenotypic alteration. The up-regulated genes were enriched in response to extracellular protein biosynthesis, photosynthesis and hormone stimulus for cell enlargement and phenotypic alteration. The genomic shock induced by chromosome duplication stimulated the expression of transcripts related to oxidative stress, biosynthesis and signal transduction of ABA and JA, and key enzymes in artemisinin biosynthetic pathway, leading to the increased accumulation of artemisinin. This is the first transcriptomic research that identifies DEGs involved in the polyploidization of A. annua. The results provide novel information for understanding the complexity of polyploidization and for further identification of the factors and genes involve in artemisinin biosynthesis.


Assuntos
Artemisia annua/genética , Artemisia annua/metabolismo , Artemisininas/metabolismo , Regulação da Expressão Gênica de Plantas/fisiologia , Tetraploidia , Oxirredução , Fotossíntese , Transcriptoma
19.
Cell Mol Biol (Noisy-le-grand) ; 64(9): 1-5, 2018 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-30030948

RESUMO

A significant sesquiterpene lactone used as a drug is artemisinin. It is definitely an anti-parasitic drug isolated from field-grown Artemisia annua L. a plant from Asteraceae family. It is the best treatment for Plasmodium falciparum malaria. Unfortunately, artemisinin content in A. annua is extremely low (0.01-0.8% dry weight). So, some researchers focused on enhancing artemisinin content either in tissue/cell culture or the whole plant of A. annua sp. The aims of the current study were the effect of plant growth regulators on callus production and improvement of artemisinin content in cell suspension culture of A. annua, an alternative to the whole plant using abiotic elicitors. For callus induction, an experiment was laid out as a factorial experiment with three factors (explant type, different concentrations of BAP and 2,4-D) based on completely randomized design with three replications. The maximum frequency of callus induction (100%) was found in leaf explant on MS medium with a combination of 2, 4-D (3 mg/l) and BAP (1.5 mg/l). Therefore, the best calli were used for cell suspension culture and the effects of GA3 and ABA as abiotic elicitors were evaluated on the improvement of artemisinin production. The results indicated that both ABA and GA3 increased artemisinin content (2.02 fold and 1.67 fold in comparison to control respectively) in cell suspension culture.


Assuntos
Ácido 2,4-Diclorofenoxiacético/farmacologia , Antimaláricos/metabolismo , Artemisia annua/química , Artemisininas/metabolismo , Compostos de Benzil/farmacologia , Células Vegetais/efeitos dos fármacos , Purinas/farmacologia , Ácido Abscísico/farmacologia , Antimaláricos/análise , Artemisia annua/metabolismo , Artemisininas/análise , Cromatografia Líquida de Alta Pressão , Giberelinas/farmacologia , Células Vegetais/química , Células Vegetais/metabolismo , Folhas de Planta/citologia , Caules de Planta/citologia
20.
Molecules ; 23(6)2018 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-29857558

RESUMO

Artemisinin, which has been isolated from Artemisiaannua L., is the most effective antimalarial drug and has saved millions of lives. In addition, artemisinin and its derivatives have anti-tumor, anti-parasitic, anti-fibrosis, and anti-arrhythmic properties, which enhances the demand for these compounds. Improving the content of artemisinin in A.annua is therefore becoming an increasing research interest, as the chemical synthesis of this metabolite is not viable. Ultraviolet B and C irradiation have been reported to improve the artemisinin content in A.annua, but they are harmful to plant growth and development. Therefore, we screened other light sources to examine if they could promote artemisinin content without affecting plant growth and development. We found that red and blue light could enhance artemisinin accumulation by promoting the expression of the genes that were involved in artemisinin biosynthesis, such as amorpha-4,11-diene synthase (ADS) and cytochrome P450 monooxygenase (CYP71AV1) genes. Thus, in addition to being the main light sources for photosynthesis, red and blue light play a key role in plant secondary metabolism, and optimizing the combination of these light might allow for the productionof artemisinin-rich A.annua.


Assuntos
Artemisia annua/metabolismo , Artemisia annua/efeitos da radiação , Artemisininas/metabolismo , Luz , Fotossíntese , Artemisia annua/classificação , Artemisia annua/genética , Vias Biossintéticas , Biologia Computacional/métodos , DNA Espaçador Ribossômico , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Anotação de Sequência Molecular , Reprodutibilidade dos Testes , Metabolismo Secundário , Transcriptoma
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