In order to study the effects of drought stress on the morphological and physiological indexes of Yunnan Coix at different growth stages, two new varieties of Yunnan Coix Wenyi 4 and Wenyi 5 were used as experimental ...In order to study the effects of drought stress on the morphological and physiological indexes of Yunnan Coix at different growth stages, two new varieties of Yunnan Coix Wenyi 4 and Wenyi 5 were used as experimental materials, potted and compared with CK by normal irrigation. Morphological indices such as plant height, stem diameter and physiological indices such as protein, soluble sugar, chlorophyll content and relative conductivity (REC) of the two varieties under drought stress at seedling stage, tillering stage and jointing stage were determined, and data statistics and variance analysis were performed for each index. The results showed that the morphological indices, plant height of Wenyi 4 and Wenyi 5 were significantly affected by drought stress at seedling stage, while the stem diameter was significantly affected by drought stress at seedling and jointing stage. In terms of physiological indices, the relative conductivity, protein and soluble sugar contents of Wenyi 5 increased at a higher degree, whereas chlorophyll content decreased at a higher degree, indicating that Wenyi 5 was greatly affected by drought stress. Through the analysis of drought resistance of the tested materials at different stages by polar ordination method, the results were as follows: jointing stage of Wenyi 5>jointing stage of Wenyi 4>seedling stage of Wenyi 4>seedling stage of Wenyi 5>tillering Stage of Wenyi 4>Tillering Stage of Wenyi 5. For the growth period, the drought resistance was as follows: jointing stage>seedling stage>tillering stage. In conclusion, Wenyi 4 has strong drought resistance and is suitable for droughtresistant cultivation.展开更多
Cucurbitacin IIa is a triterpenoid isolated exclusively from Hemsleya plants and a non-steroidal anti-inflammatory drug that functions as the main ingredient of prescription Hemslecin capsules and tablets in China.Syn...Cucurbitacin IIa is a triterpenoid isolated exclusively from Hemsleya plants and a non-steroidal anti-inflammatory drug that functions as the main ingredient of prescription Hemslecin capsules and tablets in China.Synthetic biology provides new strategies for production of such valuable cucurbitacins at a large scale;however,the biosynthetic pathway of cucurbitacin IIa has been unknown,and the heterologous production of cucurbitacins in galactose medium has been expensive and low yielding.In this study,we characterized the functions of genes encoding two squalene epoxidases(HcSE1-2),six oxidosqualene cyclases(HcOSC1-6),two CYP450s(HcCYP87D20 and HcCYP81Q59),and an acyltransferase(HcAT1)in cucurbitacin IIa biosynthesis by heterologous expression in Saccharomyces cerevisiae and Nicotiana benthamiana.We achieved high-level production of the key cucurbitacin precursor 11-carbonyl-20b-hydroxy-Cuol from glucose in yeast via modular engineering of the mevalonate pathway and optimization of P450 expression levels.The resulting yields of 46.41 mg/l 11-carbonyl-20b-hydroxy-Cuol and 126.47 mg/l total cucurbitacin triterpenoids in shake flasks are the highest yields yet reported from engineered microbes.Subsequently,production of 11-carbonyl-20b-hydroxy-Cuol by transient gene expression in tobacco resulted in yields of 1.28 mg/g dry weight in leaves.This work reveals the key genes involved in biosynthesis of prescription cucurbitacin IIa and demonstrates that engineered yeast cultivated with glucose can produce high yields of key triterpenoid intermediates.We describe a low-cost and highly efficient platform for rapid screening of candidate genes and high-yield production of pharmacological triterpenoids.展开更多
Medicinal plants represent a huge reservoir of secondary metabolites(SMs),substances with significant pharmaceutical and industrial potential.However,obtaining secondary metabolites remains a challenge due to their lo...Medicinal plants represent a huge reservoir of secondary metabolites(SMs),substances with significant pharmaceutical and industrial potential.However,obtaining secondary metabolites remains a challenge due to their low-yield accumulation in medicinal plants;moreover,these secondary metabolites are produced through tightly coordinated pathways involving many spatiotemporally and environmentally regulated steps.The first regulatory layer involves a complex network of transcription factors;a second,more recently discovered layer of complexity in the regulation of SMs is epigenetic modification,such as DNA methylation,histone modification and small RNA-based mechanisms,which can jointly or separately influence secondary metabolites by regulating gene expression.Here,we summarize the findings in the fields of genetic and epigenetic regulation with a special emphasis on SMs in medicinal plants,providing a new perspective on the multiple layers of regulation of gene expression.展开更多
Gene duplication is assumed to be the major force driving the evolution of metabolite biosynthesis in plants.Freed from functional burdens,duplicated genes can mutate toward novelties until fixed due to selective fitn...Gene duplication is assumed to be the major force driving the evolution of metabolite biosynthesis in plants.Freed from functional burdens,duplicated genes can mutate toward novelties until fixed due to selective fitness.However,the extent to which this mechanism has driven the diversification of metabolite biosynthesis remains to be tested.Here we performed comparative genomics analysis and functional characterization to evaluate the impact of gene duplication on the evolution of triterpenoid biosynthesis using Panax species as models.Wefound that whole-genome duplications(WGDs)occurred independently in Araliaceae and Apiaceae lineages.Comparative genomics revealed the evolutionary trajectories of triterpenoid biosynthesis in plants,which was mainly promoted by WGDs and tandem duplication.Lanosterol synthase(LAS)was likely derived from a tandemduplicate of cycloartenol synthase that predated the emergence of Nymphaeales.Under episodic diversifying selection,the LAS gene duplicates produced by g whole-genome triplication have given rise to triterpene biosynthesis in core eudicots through neofunctionalization.Moreover,functional characterization revealed that oxidosqualene cyclases(OSCs)responsible for synthesizing dammarane-type triterpenes in Panax species were also capable of producing ocotilloltype triterpenes.Genomic and biochemical evidence suggested that Panax genes encoding the above OSCs originated from the specialization of one OSC gene duplicate produced from a recent WGD shared by Araliaceae(Pg-b).Our results reveal the crucial role of gene duplication in diversification of triterpenoid biosynthesis in plants and provide insight into the origin of ocotillol-type triterpenes in Panax species.展开更多
Dear Editor ,More than 50% of drugs are derived from chemical compounds that have been isolated from various plants （Fabricant and Farnsworth, 2001; Yarnell and Abascal, 2002）. With the development of sequencing tec...Dear Editor ,More than 50% of drugs are derived from chemical compounds that have been isolated from various plants （Fabricant and Farnsworth, 2001; Yarnell and Abascal, 2002）. With the development of sequencing technology and synthetic biology, we can obtain molecular information from the transcriptomic and genomic data of plants and then utilize bacteria to synthesize desired chemical compounds （Atanasov et al., 2015; Smanski et al., 2016）. Increasing numbers of researchers have started to publish omics data generated from herbal plants.展开更多
Natural product biosynthesis in medicinal plants has always been a research focus in biology.Terpenoids,phenolics,and alkaloids,all of which have medicinal value for humans,are the three most prominent natural product...Natural product biosynthesis in medicinal plants has always been a research focus in biology.Terpenoids,phenolics,and alkaloids,all of which have medicinal value for humans,are the three most prominent natural products found in medicinal plants(Cravens et al.2019;Li et al.2023;Zhao et al.2023).Many medicinal plants produce natural products that have special biological functions,such as regulating plant growth and resisting stress.展开更多
文摘In order to study the effects of drought stress on the morphological and physiological indexes of Yunnan Coix at different growth stages, two new varieties of Yunnan Coix Wenyi 4 and Wenyi 5 were used as experimental materials, potted and compared with CK by normal irrigation. Morphological indices such as plant height, stem diameter and physiological indices such as protein, soluble sugar, chlorophyll content and relative conductivity (REC) of the two varieties under drought stress at seedling stage, tillering stage and jointing stage were determined, and data statistics and variance analysis were performed for each index. The results showed that the morphological indices, plant height of Wenyi 4 and Wenyi 5 were significantly affected by drought stress at seedling stage, while the stem diameter was significantly affected by drought stress at seedling and jointing stage. In terms of physiological indices, the relative conductivity, protein and soluble sugar contents of Wenyi 5 increased at a higher degree, whereas chlorophyll content decreased at a higher degree, indicating that Wenyi 5 was greatly affected by drought stress. Through the analysis of drought resistance of the tested materials at different stages by polar ordination method, the results were as follows: jointing stage of Wenyi 5>jointing stage of Wenyi 4>seedling stage of Wenyi 4>seedling stage of Wenyi 5>tillering Stage of Wenyi 4>Tillering Stage of Wenyi 5. For the growth period, the drought resistance was as follows: jointing stage>seedling stage>tillering stage. In conclusion, Wenyi 4 has strong drought resistance and is suitable for droughtresistant cultivation.
基金supported by the Major Science and Technology Projects in Yunnan Province(2019ZF011-1)the Fundamental Research Project of Yunnan(202101AS070037)+4 种基金the Science and Technology Innovation team of Yunnan(202105AE160011)the Major Science and Technique Programs in Yunnan Province(202102AE090042)the Yunnan Characteristic Plant Extraction Laboratory(2022YKZY001)the First Projects of Science and Technology Plan in the Biomedical field in 2021(202102AA310048)the National Natural Science Foundation of China(grant nos.81960691 and 82160727).
文摘Cucurbitacin IIa is a triterpenoid isolated exclusively from Hemsleya plants and a non-steroidal anti-inflammatory drug that functions as the main ingredient of prescription Hemslecin capsules and tablets in China.Synthetic biology provides new strategies for production of such valuable cucurbitacins at a large scale;however,the biosynthetic pathway of cucurbitacin IIa has been unknown,and the heterologous production of cucurbitacins in galactose medium has been expensive and low yielding.In this study,we characterized the functions of genes encoding two squalene epoxidases(HcSE1-2),six oxidosqualene cyclases(HcOSC1-6),two CYP450s(HcCYP87D20 and HcCYP81Q59),and an acyltransferase(HcAT1)in cucurbitacin IIa biosynthesis by heterologous expression in Saccharomyces cerevisiae and Nicotiana benthamiana.We achieved high-level production of the key cucurbitacin precursor 11-carbonyl-20b-hydroxy-Cuol from glucose in yeast via modular engineering of the mevalonate pathway and optimization of P450 expression levels.The resulting yields of 46.41 mg/l 11-carbonyl-20b-hydroxy-Cuol and 126.47 mg/l total cucurbitacin triterpenoids in shake flasks are the highest yields yet reported from engineered microbes.Subsequently,production of 11-carbonyl-20b-hydroxy-Cuol by transient gene expression in tobacco resulted in yields of 1.28 mg/g dry weight in leaves.This work reveals the key genes involved in biosynthesis of prescription cucurbitacin IIa and demonstrates that engineered yeast cultivated with glucose can produce high yields of key triterpenoid intermediates.We describe a low-cost and highly efficient platform for rapid screening of candidate genes and high-yield production of pharmacological triterpenoids.
基金Open access funding provided by Shanghai Jiao Tong Universitysupported by the National Natural Science Foundation of China(No.81960691 to Y.Z.,81760694 to Y.Z.,31971543 to Y.L.,32260095 to G.L.)+2 种基金Yunnan Characteristic Plant Extraction Laboratory(2022YKZY001 to S.Y.)the Major Special Science and Technology Project of Yunnan Province(No.202102AA310031 to Y.L.)Yunnan Province Youth Talent Support Program(No.YNWR-QNBJ-2018-324 to L.Y.,XDYCQNRC-2022-0219 to Y.Z.).
文摘Medicinal plants represent a huge reservoir of secondary metabolites(SMs),substances with significant pharmaceutical and industrial potential.However,obtaining secondary metabolites remains a challenge due to their low-yield accumulation in medicinal plants;moreover,these secondary metabolites are produced through tightly coordinated pathways involving many spatiotemporally and environmentally regulated steps.The first regulatory layer involves a complex network of transcription factors;a second,more recently discovered layer of complexity in the regulation of SMs is epigenetic modification,such as DNA methylation,histone modification and small RNA-based mechanisms,which can jointly or separately influence secondary metabolites by regulating gene expression.Here,we summarize the findings in the fields of genetic and epigenetic regulation with a special emphasis on SMs in medicinal plants,providing a new perspective on the multiple layers of regulation of gene expression.
基金supported by Digitalization of biological resources(202002AA100007)the Guangxi Innovation-Driven Development Project(GuiKe AA18242040)+1 种基金the General Project for Basic Research in Yunnan(grant no.202201AT070266)the National Natural Science Foundation of China(81860680)。
文摘Gene duplication is assumed to be the major force driving the evolution of metabolite biosynthesis in plants.Freed from functional burdens,duplicated genes can mutate toward novelties until fixed due to selective fitness.However,the extent to which this mechanism has driven the diversification of metabolite biosynthesis remains to be tested.Here we performed comparative genomics analysis and functional characterization to evaluate the impact of gene duplication on the evolution of triterpenoid biosynthesis using Panax species as models.Wefound that whole-genome duplications(WGDs)occurred independently in Araliaceae and Apiaceae lineages.Comparative genomics revealed the evolutionary trajectories of triterpenoid biosynthesis in plants,which was mainly promoted by WGDs and tandem duplication.Lanosterol synthase(LAS)was likely derived from a tandemduplicate of cycloartenol synthase that predated the emergence of Nymphaeales.Under episodic diversifying selection,the LAS gene duplicates produced by g whole-genome triplication have given rise to triterpene biosynthesis in core eudicots through neofunctionalization.Moreover,functional characterization revealed that oxidosqualene cyclases(OSCs)responsible for synthesizing dammarane-type triterpenes in Panax species were also capable of producing ocotilloltype triterpenes.Genomic and biochemical evidence suggested that Panax genes encoding the above OSCs originated from the specialization of one OSC gene duplicate produced from a recent WGD shared by Araliaceae(Pg-b).Our results reveal the crucial role of gene duplication in diversification of triterpenoid biosynthesis in plants and provide insight into the origin of ocotillol-type triterpenes in Panax species.
文摘Dear Editor ,More than 50% of drugs are derived from chemical compounds that have been isolated from various plants （Fabricant and Farnsworth, 2001; Yarnell and Abascal, 2002）. With the development of sequencing technology and synthetic biology, we can obtain molecular information from the transcriptomic and genomic data of plants and then utilize bacteria to synthesize desired chemical compounds （Atanasov et al., 2015; Smanski et al., 2016）. Increasing numbers of researchers have started to publish omics data generated from herbal plants.
基金supported by the National Natural Science Foundation of China(No.81960691 to Y.Z.81760694 to Y.Z.)+1 种基金Yunnan Characteristic Plant Extraction Laboratory(2022YKZY001 to S.Y.)Yunnan Province Youth Talent Support Program(XDYC-QNRC-2022-0219 to Y.Z.).
文摘Natural product biosynthesis in medicinal plants has always been a research focus in biology.Terpenoids,phenolics,and alkaloids,all of which have medicinal value for humans,are the three most prominent natural products found in medicinal plants(Cravens et al.2019;Li et al.2023;Zhao et al.2023).Many medicinal plants produce natural products that have special biological functions,such as regulating plant growth and resisting stress.
