Coccidiosis is a disease caused by protozoa of the genus Eimeria which seriously affects young rabbits. Treatment based on the use of anticoccidial drugs is increasingly ineffective due to the rapid emergence of resis...Coccidiosis is a disease caused by protozoa of the genus Eimeria which seriously affects young rabbits. Treatment based on the use of anticoccidial drugs is increasingly ineffective due to the rapid emergence of resistant strains of coccidia and the high cost of drugs. Consumer demand for rabbit products without chemical residues led to a growing interest in the use of medicinal plants as an alternative treatment for coccidiosis. The present study was carried out during the period of August to December 2020 to assess the anticoccidial effect of hydro-ethanolic extract of leaves of Artemisia annua L., in young rabbits. The antiparasitic efficacy of Artemisia extract was tested on 15 young rabbits (whose age varied between 7 and 9 weeks) divided into 5 lots of 3 animals. The average weight of these animals was 790 g. The results of this study show that the feces samples and the weight of young rabbits before administration of the treatment and the coprological examination (every 7 days for 4 weeks) show a fecal excretion reduction rate (FECRT) of 55.13% in the lot treated by sulfonamide. On the other hand, in animals received treatments extract of the leaves of Artemisia annua L., the average FECRT is evaluated at 69.64%, 79.22%, and 96.36% for respective doses of 400, 800 and 1200 mg/kg bodyweight and proves their anticoccidial effect. Furthermore, the variation in mean Eggs Per Gram (EPG) of coccidia and the average weekly weight gain (AWWG) of each lot were significant in the lots treated with hydro-ethanolic extract (P 0.05). The greatest reductions in oocystal excretion and weight gain obtained were those of lot 5, treated at 1200 mg/kg of hydro-ethanolic leaves extract of Artemisia annua L.展开更多
The sesquiterpene lactone artemisinin is an important anti-malarial component produced by the glandular secretory trichomes of sweet wormwood(Artemisia annua L.).Light was previously shown to promote artemisinin produ...The sesquiterpene lactone artemisinin is an important anti-malarial component produced by the glandular secretory trichomes of sweet wormwood(Artemisia annua L.).Light was previously shown to promote artemisinin production,but the underlying regulatory mechanism remains elusive.In this study,we demonstrate that ELONGATED HYPOCOTYL5(HY5),a central transcription factor in the light signaling pathway,cannot promote artemisinin biosynthesis on its own,as the binding of AaHY5 to the promoters of artemisinin biosynthetic genes failed to activate their transcription.Transcriptome analysis and yeast two-hybrid screening revealed the B-box transcription factor AaBBX21 as a potential interactor with AaHY5.AaBBX21 showed a trichome-specific expression pattern.Additionally,the AaBBX21–AaHY5 complex cooperatively activated transcription from the promoters of the downstream genes AaGSW1,AaMYB108,and AaORA,encoding positive regulators of artemisinin biosynthesis.Moreover,AaHY5 and AaBBX21 physically interacted with the A.annua E3 ubiquitin ligase CONSTITUTIVELY PHOTOMORPHOGENIC 1(COP1).In the dark,AaCOP1 decreased the accumulation of AaHY5 and AaBBX21 and repressed the activation of genes downstream of the AaHY5–AaBBX21 complex,explaining the enhanced production of artemisinin upon light exposure.Our study provides insights into the central regulatory mechanism by which light governs terpenoid biosynthesis in the plant kingdom.展开更多
Artemisinin, also known as qinghaosu, a sesquiterpene endoperoxide lactone isolated from the Chinese medicinal plant Artemisia annua L., is the most effective antimalarial drug which has saved millions of lives.Due to...Artemisinin, also known as qinghaosu, a sesquiterpene endoperoxide lactone isolated from the Chinese medicinal plant Artemisia annua L., is the most effective antimalarial drug which has saved millions of lives.Due to its great antimalarial activity and low content in wild A. annua plants, researches focused on enhancing the artemisin yield in plants became a hotspot. Several families of transcription factors have been reported to participate in regulating the biosynthesis and accumulation of artemisinin.In this review, we summarize recent investigations in these fields, with emphasis on newly identified transcription factors and their functions in artemisinin biosynthesis regulation, and provide new insight for further research.展开更多
Artemisinin, the key ingredient of first-line antimalarial drugs, has large demand every year. The native plant, which produces small quantities of artemisinin, remains as its main source and thus results in a short s...Artemisinin, the key ingredient of first-line antimalarial drugs, has large demand every year. The native plant, which produces small quantities of artemisinin, remains as its main source and thus results in a short supply of artemisinin. Intensified efforts have been carried out to elevate artemisinin production. However, the routine metabolic engineering strategy, via overexpressing or down-regulating genes in artemisinin biosynthesis branch pathways, was not very effective as desired. Glandular secretory trichomes, sites of artemisinin biosynthesis on the surface of Artemisia annua L.(A. annua), are the new target for increasing artemisinin yield. In general, the population and morphology of glandular secretory trichomes in A. annua(Aa GSTs) are often positively correlated with artemisinin content. Improved understanding of Aa GSTs will shed light on the opportunities for increasing plant-derived artemisinin. This review article will refresh classification of trichomes in A. annua and provide an overview of the recent achievements regarding Aa GSTs and artemisinin. To have a full understanding of Aa GSTs,factors that are associated with trichome morphology and density will have to be further investigated, such as genes,micro RNAs and phytohormones. The purpose of thisreview was to(1) update the knowledge of the relation between Aa GSTs and artemisinin, and(2) propose new avenues to increase artemisinin yield by harnessing the potential biofactories, Aa GSTs.展开更多
Isochorismate synthase(ICS) is a crucial enzyme in the salicylic acid(SA) synthesis pathway. The full-length complementary DNA(cDNA) sequence of the ICS gene was isolated from Artemisia annua L. The gene, named AaICS...Isochorismate synthase(ICS) is a crucial enzyme in the salicylic acid(SA) synthesis pathway. The full-length complementary DNA(cDNA) sequence of the ICS gene was isolated from Artemisia annua L. The gene, named AaICS1, contained a 1710-bp open reading frame, which encoded a protein with 570 amino acids. Bioinformatics and comparative study revealed that the polypeptide protein of AaICS1 had high homology with ICSs from other plant species. Southern blot analysis suggested that AaICS1 might be a single-copy gene. Analysis of the 1470-bp promoter of AaICS1 identified distinct cis-acting regulatory elements, including TC-rich repeats, MYB binding site(MBS), and TCA-elements. An analysis of AaICS1 transcript levels in multifarious tissues of A. annua using quantitative real-time polymerase chain reaction(qRT-PCR) showed that old leaves had the highest transcription levels. AaICS1 was up-regulated under wounding, drought, salinity, and SA treatments. This was corroborated by the presence of the predicted cis-acting elements in the promoter region of AaICS1. Overexpressing transgenic plants and RNA interference transgenic lines of AaICS1 were generated and their expression was compared. High-performance liquid chromatography(HPLC) results from leaf tissue of transgenic A. annua showed an increase in artemisinin content in the overexpressing plants. These results confirm that AaICS1 is involved in the isochorismate pathway.展开更多
Objective: Artemisia annua is the chief source of artemisinin, a potent antimalarial agent, in which other bioactive phytochemicals are also present. Due to low levels of bioactive compounds including artemisinin and ...Objective: Artemisia annua is the chief source of artemisinin, a potent antimalarial agent, in which other bioactive phytochemicals are also present. Due to low levels of bioactive compounds including artemisinin and flavonoids, it is necessary to increase the level of the secondary metabolites by regulating the expression of rol genes in the plant.Methods: A hybrid variety of A. annua(Hyb1209 r, Shennong) developed by the Centre for Novel Agricultural Products, University of York, UK, was selected to produce transgenics of rolB and rolC genes. Genetic transformation was carried out via Agrobacterium tumefaciens GV3101 harboring rolB and rolC genes of Agrobacterium rhizogenes cloned separately. HPLC was used for the qualitative and quantitative analysis of flavonoids and artemisinin. Furthermore, thin layer chromatography(TLC) was also used to analyze artemisinin content.Results: Comparative analysis via HPLC revealed considerable enhancement in the phytochemical content of transgenic A. annua plants as compared to the wild type plant. Transgenics of rolB gene showed an average increase of 321% in rutin, 97.2% in caffeic acid, and 218.4% in myricetin, respectively. In the case of rolC gene transgenics, an average increase of 197.5% in rutin, 76.3% in caffeic acid, and 209.3%in myricetin was observed. Transgenics of rolB and rolC genes showed a 14.3%–28.6% and 2.8%–12.7% increase in artemisinin content respectively by HPLC analysis. TLC analysis showed that an average 142.2%and 110.2% enhancement in artemisinin for rolB and rolC transgenics respectively, compared with the wild type. An enhanced production of total flavonoids(average 30.2% and 25.5% increase in rolB and rolC transgenics, respectively) and total phenolics(average 34.3% and 25.8% increase in rolB and rolC transgenics, respectively) was observed as a result of transformation. Transformed A. annua plants showed improved free radical scavenging activity(average 46.5% and 29.1% increase in rolB and rolC transgenics,respectively) and total reducing power(average 32.7% and 26.4% increase in rolB and rolC transgenics,respectively) compared with untransformed plant.Conclusion: rolB and rolC genes were effective for developing A. annua plants with an enhanced level of phytochemicals.展开更多
Derivation conditions of pre-column derivation-HPLC method used for determinating artemisinin content were compared and selected,and artemisinin content in above-ground part of Artemisia annua L.from seventeen locatio...Derivation conditions of pre-column derivation-HPLC method used for determinating artemisinin content were compared and selected,and artemisinin content in above-ground part of Artemisia annua L.from seventeen locations was compared by optimal pre-column derivation-HPLC method.The optimal derivation condition is selected via comparing of 0.2% NaOH solution addition(3,4,5,6 and 7 mL),derivation temperature(30 ℃,35 ℃,40 ℃,45 ℃ and 50 ℃) and derivation time(0,2,5,10,20,40 and 60 min) during derivation process.The optimal derivation condition is adding 5 mL 0.2% NaOH solution,then insulating in 40 ℃ water bath for 10 min.Differences of artemisinin content in A.annua from seventeen locations are obvious,the general trend is that artemisinin content decreases gradually with location from south to north,in which artemisinin content in A.annua from Youyang of Chongqing is the highest with a value of 7.08 mg·g-1.The method is simple and accurate with good reproducibility,and can be used to determinate artemisinin content in medicinal material of A.annua.展开更多
Arteannuic acid and(-)11R,13-d(?)ydroarteannuic acid are the key intermediates in the biosynthesis of arteannuin by the leaf homogenate of Artemisia annua L.,and arteannuic acid and epoxyarteannuic acid are the interm...Arteannuic acid and(-)11R,13-d(?)ydroarteannuic acid are the key intermediates in the biosynthesis of arteannuin by the leaf homogenate of Artemisia annua L.,and arteannuic acid and epoxyarteannuic acid are the intermediates of arteannuin B.and epoxyarteannuic acid can not be transformed into arteannuin by the homogenate.展开更多
The important antimalarial drug artemisinin is biosynthesized and stored in Artemisia annua glandular trichomes and the artemisinin content correlates with trichome density;however,the factors affecting trichome devel...The important antimalarial drug artemisinin is biosynthesized and stored in Artemisia annua glandular trichomes and the artemisinin content correlates with trichome density;however,the factors affecting trichome development are largely unknown.Here,we demonstrate that the A.annua R2R3 MYB transcription factor TrichomeLess Regulator 1(TLR1)negatively regulates trichome development.In A.annua,TLR1 overexpression lines had 44.7%–64.0%lower trichome density and 11.5%–49.4%lower artemisinin contents and TLR1-RNAi lines had 33%–93.3%higher trichome density and 32.2%–84.0%higher artemisinin contents compared with non-transgenic controls.TLR1 also negatively regulates the expression of anthocyanin biosynthetic pathway genes in A.annua.When heterologously expressed in Arabidopsis thaliana,TLR1 interacts with GLABROUS3a,positive regulator of trichome development,and represses trichome development.Yeast two-hybrid and pull-down assays indicated that TLR1 interacts with the WUSCHEL homeobox(WOX)protein AaWOX1,which interacts with the LEAFY-like transcription factor TLR2.TLR2 overexpression in Arabidopsis and A.annua showed that TLR2 reduces trichome development by reducing gibberellin levels.Furthermore,artemisinin contents were 19%–43%lower in TLR2-overexpressing A.annua plants compared to controls.These data indicate that TLR1 and TLR2 negatively regulate trichome density by lowering gibberellin levels and may enable approaches to enhance artemisinin yields.展开更多
文摘Coccidiosis is a disease caused by protozoa of the genus Eimeria which seriously affects young rabbits. Treatment based on the use of anticoccidial drugs is increasingly ineffective due to the rapid emergence of resistant strains of coccidia and the high cost of drugs. Consumer demand for rabbit products without chemical residues led to a growing interest in the use of medicinal plants as an alternative treatment for coccidiosis. The present study was carried out during the period of August to December 2020 to assess the anticoccidial effect of hydro-ethanolic extract of leaves of Artemisia annua L., in young rabbits. The antiparasitic efficacy of Artemisia extract was tested on 15 young rabbits (whose age varied between 7 and 9 weeks) divided into 5 lots of 3 animals. The average weight of these animals was 790 g. The results of this study show that the feces samples and the weight of young rabbits before administration of the treatment and the coprological examination (every 7 days for 4 weeks) show a fecal excretion reduction rate (FECRT) of 55.13% in the lot treated by sulfonamide. On the other hand, in animals received treatments extract of the leaves of Artemisia annua L., the average FECRT is evaluated at 69.64%, 79.22%, and 96.36% for respective doses of 400, 800 and 1200 mg/kg bodyweight and proves their anticoccidial effect. Furthermore, the variation in mean Eggs Per Gram (EPG) of coccidia and the average weekly weight gain (AWWG) of each lot were significant in the lots treated with hydro-ethanolic extract (P 0.05). The greatest reductions in oocystal excretion and weight gain obtained were those of lot 5, treated at 1200 mg/kg of hydro-ethanolic leaves extract of Artemisia annua L.
基金supported by the National Natural Science Foundation of China (32070329, 31770327)Shanghai Natural Science Foundation (16ZR1418000)the National Key R&D Program of China (2018Y FA0900600)。
文摘The sesquiterpene lactone artemisinin is an important anti-malarial component produced by the glandular secretory trichomes of sweet wormwood(Artemisia annua L.).Light was previously shown to promote artemisinin production,but the underlying regulatory mechanism remains elusive.In this study,we demonstrate that ELONGATED HYPOCOTYL5(HY5),a central transcription factor in the light signaling pathway,cannot promote artemisinin biosynthesis on its own,as the binding of AaHY5 to the promoters of artemisinin biosynthetic genes failed to activate their transcription.Transcriptome analysis and yeast two-hybrid screening revealed the B-box transcription factor AaBBX21 as a potential interactor with AaHY5.AaBBX21 showed a trichome-specific expression pattern.Additionally,the AaBBX21–AaHY5 complex cooperatively activated transcription from the promoters of the downstream genes AaGSW1,AaMYB108,and AaORA,encoding positive regulators of artemisinin biosynthesis.Moreover,AaHY5 and AaBBX21 physically interacted with the A.annua E3 ubiquitin ligase CONSTITUTIVELY PHOTOMORPHOGENIC 1(COP1).In the dark,AaCOP1 decreased the accumulation of AaHY5 and AaBBX21 and repressed the activation of genes downstream of the AaHY5–AaBBX21 complex,explaining the enhanced production of artemisinin upon light exposure.Our study provides insights into the central regulatory mechanism by which light governs terpenoid biosynthesis in the plant kingdom.
基金supported by National High Technology Research and Development Program(2011AA100605)Shanghai Key Discipline Cultivation and Construction Project(Horticulture+1 种基金ZXDF150005)Shanghai Jiao Tong University Agri-Engineering Program(AF1500028)
文摘Artemisinin, also known as qinghaosu, a sesquiterpene endoperoxide lactone isolated from the Chinese medicinal plant Artemisia annua L., is the most effective antimalarial drug which has saved millions of lives.Due to its great antimalarial activity and low content in wild A. annua plants, researches focused on enhancing the artemisin yield in plants became a hotspot. Several families of transcription factors have been reported to participate in regulating the biosynthesis and accumulation of artemisinin.In this review, we summarize recent investigations in these fields, with emphasis on newly identified transcription factors and their functions in artemisinin biosynthesis regulation, and provide new insight for further research.
基金supported by the National Natural Science Foundation of China (Grant Nos. 31300159 U1405215)+2 种基金‘‘Pujiang Talent’’ program (13PJ1411000) Shanghai Science and Technology Development Funds (14QB1402700)Program 15391900500 from Science and Technology Commission of Shanghai Municipality and Technology Committee and Seedling Cultivation Fund of Outstanding Master, Second Military Medical University
文摘Artemisinin, the key ingredient of first-line antimalarial drugs, has large demand every year. The native plant, which produces small quantities of artemisinin, remains as its main source and thus results in a short supply of artemisinin. Intensified efforts have been carried out to elevate artemisinin production. However, the routine metabolic engineering strategy, via overexpressing or down-regulating genes in artemisinin biosynthesis branch pathways, was not very effective as desired. Glandular secretory trichomes, sites of artemisinin biosynthesis on the surface of Artemisia annua L.(A. annua), are the new target for increasing artemisinin yield. In general, the population and morphology of glandular secretory trichomes in A. annua(Aa GSTs) are often positively correlated with artemisinin content. Improved understanding of Aa GSTs will shed light on the opportunities for increasing plant-derived artemisinin. This review article will refresh classification of trichomes in A. annua and provide an overview of the recent achievements regarding Aa GSTs and artemisinin. To have a full understanding of Aa GSTs,factors that are associated with trichome morphology and density will have to be further investigated, such as genes,micro RNAs and phytohormones. The purpose of thisreview was to(1) update the knowledge of the relation between Aa GSTs and artemisinin, and(2) propose new avenues to increase artemisinin yield by harnessing the potential biofactories, Aa GSTs.
基金supported by the National High-Tech R&D Program(863)of China(No.22011AA100605)
文摘Isochorismate synthase(ICS) is a crucial enzyme in the salicylic acid(SA) synthesis pathway. The full-length complementary DNA(cDNA) sequence of the ICS gene was isolated from Artemisia annua L. The gene, named AaICS1, contained a 1710-bp open reading frame, which encoded a protein with 570 amino acids. Bioinformatics and comparative study revealed that the polypeptide protein of AaICS1 had high homology with ICSs from other plant species. Southern blot analysis suggested that AaICS1 might be a single-copy gene. Analysis of the 1470-bp promoter of AaICS1 identified distinct cis-acting regulatory elements, including TC-rich repeats, MYB binding site(MBS), and TCA-elements. An analysis of AaICS1 transcript levels in multifarious tissues of A. annua using quantitative real-time polymerase chain reaction(qRT-PCR) showed that old leaves had the highest transcription levels. AaICS1 was up-regulated under wounding, drought, salinity, and SA treatments. This was corroborated by the presence of the predicted cis-acting elements in the promoter region of AaICS1. Overexpressing transgenic plants and RNA interference transgenic lines of AaICS1 were generated and their expression was compared. High-performance liquid chromatography(HPLC) results from leaf tissue of transgenic A. annua showed an increase in artemisinin content in the overexpressing plants. These results confirm that AaICS1 is involved in the isochorismate pathway.
文摘Objective: Artemisia annua is the chief source of artemisinin, a potent antimalarial agent, in which other bioactive phytochemicals are also present. Due to low levels of bioactive compounds including artemisinin and flavonoids, it is necessary to increase the level of the secondary metabolites by regulating the expression of rol genes in the plant.Methods: A hybrid variety of A. annua(Hyb1209 r, Shennong) developed by the Centre for Novel Agricultural Products, University of York, UK, was selected to produce transgenics of rolB and rolC genes. Genetic transformation was carried out via Agrobacterium tumefaciens GV3101 harboring rolB and rolC genes of Agrobacterium rhizogenes cloned separately. HPLC was used for the qualitative and quantitative analysis of flavonoids and artemisinin. Furthermore, thin layer chromatography(TLC) was also used to analyze artemisinin content.Results: Comparative analysis via HPLC revealed considerable enhancement in the phytochemical content of transgenic A. annua plants as compared to the wild type plant. Transgenics of rolB gene showed an average increase of 321% in rutin, 97.2% in caffeic acid, and 218.4% in myricetin, respectively. In the case of rolC gene transgenics, an average increase of 197.5% in rutin, 76.3% in caffeic acid, and 209.3%in myricetin was observed. Transgenics of rolB and rolC genes showed a 14.3%–28.6% and 2.8%–12.7% increase in artemisinin content respectively by HPLC analysis. TLC analysis showed that an average 142.2%and 110.2% enhancement in artemisinin for rolB and rolC transgenics respectively, compared with the wild type. An enhanced production of total flavonoids(average 30.2% and 25.5% increase in rolB and rolC transgenics, respectively) and total phenolics(average 34.3% and 25.8% increase in rolB and rolC transgenics, respectively) was observed as a result of transformation. Transformed A. annua plants showed improved free radical scavenging activity(average 46.5% and 29.1% increase in rolB and rolC transgenics,respectively) and total reducing power(average 32.7% and 26.4% increase in rolB and rolC transgenics,respectively) compared with untransformed plant.Conclusion: rolB and rolC genes were effective for developing A. annua plants with an enhanced level of phytochemicals.
文摘Derivation conditions of pre-column derivation-HPLC method used for determinating artemisinin content were compared and selected,and artemisinin content in above-ground part of Artemisia annua L.from seventeen locations was compared by optimal pre-column derivation-HPLC method.The optimal derivation condition is selected via comparing of 0.2% NaOH solution addition(3,4,5,6 and 7 mL),derivation temperature(30 ℃,35 ℃,40 ℃,45 ℃ and 50 ℃) and derivation time(0,2,5,10,20,40 and 60 min) during derivation process.The optimal derivation condition is adding 5 mL 0.2% NaOH solution,then insulating in 40 ℃ water bath for 10 min.Differences of artemisinin content in A.annua from seventeen locations are obvious,the general trend is that artemisinin content decreases gradually with location from south to north,in which artemisinin content in A.annua from Youyang of Chongqing is the highest with a value of 7.08 mg·g-1.The method is simple and accurate with good reproducibility,and can be used to determinate artemisinin content in medicinal material of A.annua.
基金This project was supported by National Natural Science Foundation of China.
文摘Arteannuic acid and(-)11R,13-d(?)ydroarteannuic acid are the key intermediates in the biosynthesis of arteannuin by the leaf homogenate of Artemisia annua L.,and arteannuic acid and epoxyarteannuic acid are the intermediates of arteannuin B.and epoxyarteannuic acid can not be transformed into arteannuin by the homogenate.
基金funded by the National Key R&D Program of China (2019YFC1711100)National Natural Science Foundation of China (32070332)+1 种基金Shanghai Natural Science Foundation in China (20ZR1453800)Shanghai local Science and Technology Development Fund Program guided by the Central Government (YDZX20203100002948)
文摘The important antimalarial drug artemisinin is biosynthesized and stored in Artemisia annua glandular trichomes and the artemisinin content correlates with trichome density;however,the factors affecting trichome development are largely unknown.Here,we demonstrate that the A.annua R2R3 MYB transcription factor TrichomeLess Regulator 1(TLR1)negatively regulates trichome development.In A.annua,TLR1 overexpression lines had 44.7%–64.0%lower trichome density and 11.5%–49.4%lower artemisinin contents and TLR1-RNAi lines had 33%–93.3%higher trichome density and 32.2%–84.0%higher artemisinin contents compared with non-transgenic controls.TLR1 also negatively regulates the expression of anthocyanin biosynthetic pathway genes in A.annua.When heterologously expressed in Arabidopsis thaliana,TLR1 interacts with GLABROUS3a,positive regulator of trichome development,and represses trichome development.Yeast two-hybrid and pull-down assays indicated that TLR1 interacts with the WUSCHEL homeobox(WOX)protein AaWOX1,which interacts with the LEAFY-like transcription factor TLR2.TLR2 overexpression in Arabidopsis and A.annua showed that TLR2 reduces trichome development by reducing gibberellin levels.Furthermore,artemisinin contents were 19%–43%lower in TLR2-overexpressing A.annua plants compared to controls.These data indicate that TLR1 and TLR2 negatively regulate trichome density by lowering gibberellin levels and may enable approaches to enhance artemisinin yields.