满天星是当今世界最流行的鲜切花配花之一,茎腐病是满天星的一种常见病害,严重时导致植株枯萎死亡,影响鲜花的观赏性和利用价值,造成一定的经济损失。2021年3月,笔者在云南省昆明市海口镇发现满天星茎腐病,该病主要为害茎基部,表现为茎...满天星是当今世界最流行的鲜切花配花之一,茎腐病是满天星的一种常见病害,严重时导致植株枯萎死亡,影响鲜花的观赏性和利用价值,造成一定的经济损失。2021年3月,笔者在云南省昆明市海口镇发现满天星茎腐病,该病主要为害茎基部,表现为茎基部腐烂和萎蔫。为明确其病原,本研究对满天星茎腐病病原菌进行分离与鉴定。柯赫氏法则证明该分离物可造成满天星组培苗和盆栽苗表现出与田间病株相似的症状,经接种后获得的分离物与田间自然发病的分离物一致。通过形态学鉴定,分离物能产生大量致密的气生菌丝,颜色从白色到淡橙色或黄色不等,菌落背面有暗红色色素沉积。显微镜观察发现其分离物的分生孢子呈镰刀形,腹面较平直,背侧呈拱形,具有3~6个隔膜,分生孢子大小为(21.1~57.9)μm×(2.7~5.1)μm(n=100),未见小型分生孢子,形态学上与镰刀菌属病原真菌相似。通过对其ITS基因序列与形态学鉴定,将分离物初步确定为禾谷镰孢复合种(Fusarium graminearum species complex,FGSC),为进一步确定亚种,使用翻译延伸因子(TEF-1α)序列进行测序,发现该分离物与南方镰孢菌(F.meridionale)的同源性达100%。因此结合形态学和分子生物学特征,满天星茎腐病的病原确定为南方镰孢菌。目前国内尚未发现由南方镰孢菌侵染为害满天星茎部的相关研究报道,本研究结果将为防治满天星病害提供重要理论依据。展开更多
Background:Andrographis paniculata has been widely reported as an herbal plant for malaria treatment.The increasing rate of resistance to recommended antimalarial drugs has justified the need for a continuous search f...Background:Andrographis paniculata has been widely reported as an herbal plant for malaria treatment.The increasing rate of resistance to recommended antimalarial drugs has justified the need for a continuous search for new and more potent drugs that target all stages of the Plasmodium falciparum life cycle from natural plant sources.This study aimed to determine the antiplasmodial effect of phytocompounds derived from A.paniculata on the stages of plasmodium falciparum.Methods:Phytocompounds from A.paniculata were identified by Gas Chromatography-Mass Spectrophotometry(GCMS)analysis.The phytocompounds were screened for their druggability using Lipinski’s rule of five and subjected to Absorption,Distribution,Metabolism,Excretion,Toxicity(ADMET)and druglikeness analysis.The phytocompounds were docked against some validated drug targets at different stages of Plasmodium falciparum(hepatic,asexual,sexual,and vector targets)using PyRx software to analyze the inhibitory potential and protein-ligand interaction.Thereafter,the stability and flexibility of the best complexes were assessed through molecular dynamics simulations at 50ns using WebGRO.Result:The 7a-Isopropenyl-4,5-dimethyloctahydroinden-4-yl exhibited a higher binding affinity and better stability throughout the simulation period with P.falciparum dihydrofolate reductase-thymidylate synthase and Plasmodium falciparum M1 alanyl aminopeptidase for asexual blood stage and gametocyte stage of Plasmodium falciparum,respectively than the existing drugs.Meanwhile,N-Ethyl-3-methoxy-4-methylphenethylamine was also found to have a higher binding affinity and more stability throughout the simulation period with P.falciparum purine nucleoside phosphorylase and Plasmodium falciparum gametocyte surface protein for Hepatic schizonts stage of Plasmodium falciparum and gametocyte transmission blocking stage,respectively,than the existing drugs.Conclusion:The 7a-Isopropenyl-4,5-dimethyloctahydroinden-4-yl and N-Ethyl-3-methoxy-4 methylphenethylamine from A.paniculata are predicted as an antimalarial drug candidate.Thus,it is recommended that in vitro and in vivo bioassays be conducted on these hit compounds to validate these predictions.展开更多
文摘满天星是当今世界最流行的鲜切花配花之一,茎腐病是满天星的一种常见病害,严重时导致植株枯萎死亡,影响鲜花的观赏性和利用价值,造成一定的经济损失。2021年3月,笔者在云南省昆明市海口镇发现满天星茎腐病,该病主要为害茎基部,表现为茎基部腐烂和萎蔫。为明确其病原,本研究对满天星茎腐病病原菌进行分离与鉴定。柯赫氏法则证明该分离物可造成满天星组培苗和盆栽苗表现出与田间病株相似的症状,经接种后获得的分离物与田间自然发病的分离物一致。通过形态学鉴定,分离物能产生大量致密的气生菌丝,颜色从白色到淡橙色或黄色不等,菌落背面有暗红色色素沉积。显微镜观察发现其分离物的分生孢子呈镰刀形,腹面较平直,背侧呈拱形,具有3~6个隔膜,分生孢子大小为(21.1~57.9)μm×(2.7~5.1)μm(n=100),未见小型分生孢子,形态学上与镰刀菌属病原真菌相似。通过对其ITS基因序列与形态学鉴定,将分离物初步确定为禾谷镰孢复合种(Fusarium graminearum species complex,FGSC),为进一步确定亚种,使用翻译延伸因子(TEF-1α)序列进行测序,发现该分离物与南方镰孢菌(F.meridionale)的同源性达100%。因此结合形态学和分子生物学特征,满天星茎腐病的病原确定为南方镰孢菌。目前国内尚未发现由南方镰孢菌侵染为害满天星茎部的相关研究报道,本研究结果将为防治满天星病害提供重要理论依据。
文摘Background:Andrographis paniculata has been widely reported as an herbal plant for malaria treatment.The increasing rate of resistance to recommended antimalarial drugs has justified the need for a continuous search for new and more potent drugs that target all stages of the Plasmodium falciparum life cycle from natural plant sources.This study aimed to determine the antiplasmodial effect of phytocompounds derived from A.paniculata on the stages of plasmodium falciparum.Methods:Phytocompounds from A.paniculata were identified by Gas Chromatography-Mass Spectrophotometry(GCMS)analysis.The phytocompounds were screened for their druggability using Lipinski’s rule of five and subjected to Absorption,Distribution,Metabolism,Excretion,Toxicity(ADMET)and druglikeness analysis.The phytocompounds were docked against some validated drug targets at different stages of Plasmodium falciparum(hepatic,asexual,sexual,and vector targets)using PyRx software to analyze the inhibitory potential and protein-ligand interaction.Thereafter,the stability and flexibility of the best complexes were assessed through molecular dynamics simulations at 50ns using WebGRO.Result:The 7a-Isopropenyl-4,5-dimethyloctahydroinden-4-yl exhibited a higher binding affinity and better stability throughout the simulation period with P.falciparum dihydrofolate reductase-thymidylate synthase and Plasmodium falciparum M1 alanyl aminopeptidase for asexual blood stage and gametocyte stage of Plasmodium falciparum,respectively than the existing drugs.Meanwhile,N-Ethyl-3-methoxy-4-methylphenethylamine was also found to have a higher binding affinity and more stability throughout the simulation period with P.falciparum purine nucleoside phosphorylase and Plasmodium falciparum gametocyte surface protein for Hepatic schizonts stage of Plasmodium falciparum and gametocyte transmission blocking stage,respectively,than the existing drugs.Conclusion:The 7a-Isopropenyl-4,5-dimethyloctahydroinden-4-yl and N-Ethyl-3-methoxy-4 methylphenethylamine from A.paniculata are predicted as an antimalarial drug candidate.Thus,it is recommended that in vitro and in vivo bioassays be conducted on these hit compounds to validate these predictions.