Grape white rot is a destructive fungal disease occurring worldwide.Recently,Coniella vitis was identified as the predominant pathogen causing this disease in China.As the periderms of grape shoots are severely degrad...Grape white rot is a destructive fungal disease occurring worldwide.Recently,Coniella vitis was identified as the predominant pathogen causing this disease in China.As the periderms of grape shoots are severely degraded by C.vitis,it was speculated that cell wall-degrading enzymes(CWDEs)might play a key role in the pathogenesis of this disease.Therefore,this study aimed to examine the hydrolytic activity of the CWDEs of C.vitis.The results showed that xylanase(Xy)and xyloglucanase(XEG)had high levels of hydrolytic activity both in vitro and in vivo.Furthermore,a high-virulence fungal strain exhibited higher levels of Xy and XEG activities compared with a low-virulence strain.The genome of the fungus was found to harbor two XEG-coding genes CvGH74A and CvGH74B,which belonged to the glycoside hydrolase(GH)74 family.The expression level of CvGH74A was found to be high during pathogen infection.CvGH74A gene deletion mutants were generated using the split-marker method.The deletion of CvGH74A decreased both the hydrolytic activities of XEG and Xy and also the ability of the fungus to infect the grape leaves.No differences in the hyphal growth,morphology of colonies,or conidiation were found between theΔCvGH74A mutant strains and the wild-type strain.Together,these results suggested that CvGH74A acted as an important virulence factor,and its enzymatic activity might regulate the virulence of the pathogen.This study was novel in reporting that GH74 XEG acted as a virulence factor in C.vitis.展开更多
【目的】从区域特征的角度出发,对我国采煤塌陷区土壤特性的现有研究进行分析,并尝试总结出区域间研究结果的异同点,以期为采煤塌陷地的修复与综合治理提供依据。【方法】采用CiteSpace和VOSviewer软件,自CNKI和Web of Science核心数据...【目的】从区域特征的角度出发,对我国采煤塌陷区土壤特性的现有研究进行分析,并尝试总结出区域间研究结果的异同点,以期为采煤塌陷地的修复与综合治理提供依据。【方法】采用CiteSpace和VOSviewer软件,自CNKI和Web of Science核心数据库中选取1993~2021年采煤塌陷区土壤特性领域的相关文献,从关键词、研究区域等方面进行可视化分析。【结果】(1)近年来该领域发文数量总体呈增长趋势。(2)研究区域的选择有明显的区域集中特征,依据其区域特性可划分为中东部平原区、西北风沙区、黄土沟壑区、西南山地丘陵区四个类型。(3)中东部平原矿区地势平坦,多位于高潜水位地区,土壤含水量受开采沉陷影响较大;黄土沟壑矿区地形多起伏,塌陷区地表变形严重,物理性黏粒减少,土壤容重减少;西北风沙矿区多位于干旱半干旱地区,生态环境脆弱,开采沉陷使得土壤细小颗粒流失,土壤容重显著降低;西南山地丘陵矿区主要分布在山区,雨量充沛,塌陷区土壤容重显著增加。【结论】煤炭开采沉陷对土壤特性的影响受多种因素的限制,使得土壤颗粒与结构、土壤含水量、土壤养分等特性发生变化,且在不同区域呈现出不同的变化规律。展开更多
基金This study was supported by the earmarked fund for China Agriculture Research System(CARS-28).
文摘Grape white rot is a destructive fungal disease occurring worldwide.Recently,Coniella vitis was identified as the predominant pathogen causing this disease in China.As the periderms of grape shoots are severely degraded by C.vitis,it was speculated that cell wall-degrading enzymes(CWDEs)might play a key role in the pathogenesis of this disease.Therefore,this study aimed to examine the hydrolytic activity of the CWDEs of C.vitis.The results showed that xylanase(Xy)and xyloglucanase(XEG)had high levels of hydrolytic activity both in vitro and in vivo.Furthermore,a high-virulence fungal strain exhibited higher levels of Xy and XEG activities compared with a low-virulence strain.The genome of the fungus was found to harbor two XEG-coding genes CvGH74A and CvGH74B,which belonged to the glycoside hydrolase(GH)74 family.The expression level of CvGH74A was found to be high during pathogen infection.CvGH74A gene deletion mutants were generated using the split-marker method.The deletion of CvGH74A decreased both the hydrolytic activities of XEG and Xy and also the ability of the fungus to infect the grape leaves.No differences in the hyphal growth,morphology of colonies,or conidiation were found between theΔCvGH74A mutant strains and the wild-type strain.Together,these results suggested that CvGH74A acted as an important virulence factor,and its enzymatic activity might regulate the virulence of the pathogen.This study was novel in reporting that GH74 XEG acted as a virulence factor in C.vitis.
文摘【目的】从区域特征的角度出发,对我国采煤塌陷区土壤特性的现有研究进行分析,并尝试总结出区域间研究结果的异同点,以期为采煤塌陷地的修复与综合治理提供依据。【方法】采用CiteSpace和VOSviewer软件,自CNKI和Web of Science核心数据库中选取1993~2021年采煤塌陷区土壤特性领域的相关文献,从关键词、研究区域等方面进行可视化分析。【结果】(1)近年来该领域发文数量总体呈增长趋势。(2)研究区域的选择有明显的区域集中特征,依据其区域特性可划分为中东部平原区、西北风沙区、黄土沟壑区、西南山地丘陵区四个类型。(3)中东部平原矿区地势平坦,多位于高潜水位地区,土壤含水量受开采沉陷影响较大;黄土沟壑矿区地形多起伏,塌陷区地表变形严重,物理性黏粒减少,土壤容重减少;西北风沙矿区多位于干旱半干旱地区,生态环境脆弱,开采沉陷使得土壤细小颗粒流失,土壤容重显著降低;西南山地丘陵矿区主要分布在山区,雨量充沛,塌陷区土壤容重显著增加。【结论】煤炭开采沉陷对土壤特性的影响受多种因素的限制,使得土壤颗粒与结构、土壤含水量、土壤养分等特性发生变化,且在不同区域呈现出不同的变化规律。
