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
Lilium are highly economically valuable ornamental plants that are susceptible to Fusarium wilt caused by Fusarium oxysporum.Lilium regale Wilson,a wild lily native to China,is highly resistant to F.oxysporum.In this ...Lilium are highly economically valuable ornamental plants that are susceptible to Fusarium wilt caused by Fusarium oxysporum.Lilium regale Wilson,a wild lily native to China,is highly resistant to F.oxysporum.In this study,a WRKY transcription factor,WRKY11,was isolated from L.regale,and its function during the interaction between L.regale and F.oxysporum was characterized.The ectopic expression of LrWRKY11 in tobacco increased the resistance to F oxysporum,moreover,the transcriptome sequencing and UHPLC-MS/MS analysis indicated that the methyl salicylate and methyl jasmonate levels rose in LrWRKY11 transgenic tobacco,meanwhile,the expression of lignin/lignans biosynthesis-related genes including a dirigent(DiR)was up-regulated.The lignin/lignans contents in LrWRKY11-transgenic tobacco also significantly increased compared with the wild-type tobacco.In addition,the resistance of L.regale scales in which LrWRKY11 expression was silenced by RNAi evidently decreased,and additionally,the expression of lignin/lignans biosynthesis-related genes including LrDIR1 was significantly suppressed.Therefore,LrDIR1 and its promoter(PLrDIR1)sequence containing the W-box element were isolated from L.regale.The interaction assay indicated that LrWRKY11 specifically bound to the W-box element in PLrDIR1 and activated LrDIR1 expression.Additionally,β-glucuronidase activity in the transgenic tobacco co-expressing LrWRKY11/PLrDIR1-β-glucuronidase was higher than that in transgenic tobacco expressing PLrDIR1-β-glucuronidase alone.Furthermore,the ectopic expression of LrDIR1 in tobacco enhanced the resistance to F.oxysporum and increased the lignin/lignans accumulation.In brief,this study revealed that LrWRKY11 positively regulated L.regale resistance to F.oxysporum through interaction with salicylic acid/jasmonic acid signaling pathways and modulating LrDIR1 expression to accumulate lignin/lignans.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。
基金National Natural Sciences Foundation of China(31760586).
文摘Lilium are highly economically valuable ornamental plants that are susceptible to Fusarium wilt caused by Fusarium oxysporum.Lilium regale Wilson,a wild lily native to China,is highly resistant to F.oxysporum.In this study,a WRKY transcription factor,WRKY11,was isolated from L.regale,and its function during the interaction between L.regale and F.oxysporum was characterized.The ectopic expression of LrWRKY11 in tobacco increased the resistance to F oxysporum,moreover,the transcriptome sequencing and UHPLC-MS/MS analysis indicated that the methyl salicylate and methyl jasmonate levels rose in LrWRKY11 transgenic tobacco,meanwhile,the expression of lignin/lignans biosynthesis-related genes including a dirigent(DiR)was up-regulated.The lignin/lignans contents in LrWRKY11-transgenic tobacco also significantly increased compared with the wild-type tobacco.In addition,the resistance of L.regale scales in which LrWRKY11 expression was silenced by RNAi evidently decreased,and additionally,the expression of lignin/lignans biosynthesis-related genes including LrDIR1 was significantly suppressed.Therefore,LrDIR1 and its promoter(PLrDIR1)sequence containing the W-box element were isolated from L.regale.The interaction assay indicated that LrWRKY11 specifically bound to the W-box element in PLrDIR1 and activated LrDIR1 expression.Additionally,β-glucuronidase activity in the transgenic tobacco co-expressing LrWRKY11/PLrDIR1-β-glucuronidase was higher than that in transgenic tobacco expressing PLrDIR1-β-glucuronidase alone.Furthermore,the ectopic expression of LrDIR1 in tobacco enhanced the resistance to F.oxysporum and increased the lignin/lignans accumulation.In brief,this study revealed that LrWRKY11 positively regulated L.regale resistance to F.oxysporum through interaction with salicylic acid/jasmonic acid signaling pathways and modulating LrDIR1 expression to accumulate lignin/lignans.