目的 探究16S rDNA不同区间对药品生产环境常见细菌的种水平鉴定能力。方法 计算德国细菌古菌分类学数据库(List of Prokaryotic names with Standing in Nomenclature,LPSN)收录的所有模式菌株序列以及洁净室中常见分离细菌对应的模式...目的 探究16S rDNA不同区间对药品生产环境常见细菌的种水平鉴定能力。方法 计算德国细菌古菌分类学数据库(List of Prokaryotic names with Standing in Nomenclature,LPSN)收录的所有模式菌株序列以及洁净室中常见分离细菌对应的模式菌株在16S rDNA不同区间香农熵,分析16S rDNA不同区间的物种水平鉴定能力;对所有LPSN收录的模式菌株进行相似度差值的比较,同时收集403个具有代表性的药品生产环境分离菌株样品,进行16S rDNA测序后完成相似度差值的比较,基于相似度差值探究16S rDNA不同区间的鉴定结果区分度;考虑到不同区间对不同种属可能存在区分能力的差异,对各区间测序区分度不显著的物种进行了相关性分析。结果 16S rDNA的27F~533R区间相比其他区间(533F~1100R区间、1100F~1492R区间)具有最高的种间分辨率,同时该区间的鉴定结果中,第一顺位与第二顺位的序列相似度差值最大,扩展比对区间对提升物种间的区分度没有显著效果。结论 优先应用16S rDNA的27F~533R区间开展细菌的种水平鉴定是高效、可靠的做法。展开更多
Catalpa bungei,a fast-growing timber tree,is threatened by the lepidopteran pest Omphisa plagialis.Previous studies in our laboratory successfully generated transgenic C.bungei lines overexpressing Cry genes(Cry1Ab,Cr...Catalpa bungei,a fast-growing timber tree,is threatened by the lepidopteran pest Omphisa plagialis.Previous studies in our laboratory successfully generated transgenic C.bungei lines overexpressing Cry genes(Cry1Ab,Cry2A,and Cry9-2)that exhibited resistance to O.plagialis,but their potential impact on soil bacterial communities remains unclear.In this study,we analyzed nine transgenic C.bungei lines(three independent lines for each Cry gene)to characterize their rhizosphere bacterial communities using high-throughput sequencing of the 16S ribosomal DNA(rDNA)V4-V5 regions.A total of 628 amplicon sequence variants(ASVs)were shared among all transgenic and wild-type(WT)lines,forming a stable core microbiome dominated by Proteobacteria,Bacteroidota,Acidobacteriota,and Actinobacteriota.Alpha diversity showed no significant differences,while beta diversity revealed minor but distinct compositional shifts.Cry1Ab lines exhibited higher abundances of fast-growing taxa,particularly Proteobacteria and Bacteroidota;Cry2A lines displayed intermediate profiles,whereas Cry9-2 lines were nearly indistinguishable from WT communities.Linear discriminant analysis of the effect size revealed significant enrichment of taxa such as Burkholderiaceae and Ralstonia in the Cry1Ab rhizosphere,in contrast to the higher abundance of Chloroflexi in the WT.Functional predictions indicated consistent metabolic pathways across all treatments,suggesting strong ecological redundancy.This study demonstrates minimal impact on rhizosphere microbial communities in transgenic C.bungei plants.The Cry9-2 construct exhibited superior environmental stability,whereas the Cry1Ab construct caused only slight but ecologically acceptable shifts.These findings support the ecological safety of Bt-transgenic C.bungei and identify Cry9-2 as a particularly favorable candidate for forestry applications.This comparative evaluation of three Cry genes in a tree species provides a framework for future gene-specific biosafety assessments in woody plants.展开更多
基金funded by the Chinese Academy of Forestry-Special funds for basic scientific research service expenses of the central level public welfare research institutes(Grant No.CAFYBB2020QD001)the National Natural Science Foundation of China(Grant Nos.32101550,32271917)+1 种基金Jiangsu Agricultural Science and Technology Innovation Fund(Grant No.CX(24)3052)National Forestry and Grassland Administration’s Center for Science and Technology Development Projects(Grant No.KJZXSA202202).
文摘Catalpa bungei,a fast-growing timber tree,is threatened by the lepidopteran pest Omphisa plagialis.Previous studies in our laboratory successfully generated transgenic C.bungei lines overexpressing Cry genes(Cry1Ab,Cry2A,and Cry9-2)that exhibited resistance to O.plagialis,but their potential impact on soil bacterial communities remains unclear.In this study,we analyzed nine transgenic C.bungei lines(three independent lines for each Cry gene)to characterize their rhizosphere bacterial communities using high-throughput sequencing of the 16S ribosomal DNA(rDNA)V4-V5 regions.A total of 628 amplicon sequence variants(ASVs)were shared among all transgenic and wild-type(WT)lines,forming a stable core microbiome dominated by Proteobacteria,Bacteroidota,Acidobacteriota,and Actinobacteriota.Alpha diversity showed no significant differences,while beta diversity revealed minor but distinct compositional shifts.Cry1Ab lines exhibited higher abundances of fast-growing taxa,particularly Proteobacteria and Bacteroidota;Cry2A lines displayed intermediate profiles,whereas Cry9-2 lines were nearly indistinguishable from WT communities.Linear discriminant analysis of the effect size revealed significant enrichment of taxa such as Burkholderiaceae and Ralstonia in the Cry1Ab rhizosphere,in contrast to the higher abundance of Chloroflexi in the WT.Functional predictions indicated consistent metabolic pathways across all treatments,suggesting strong ecological redundancy.This study demonstrates minimal impact on rhizosphere microbial communities in transgenic C.bungei plants.The Cry9-2 construct exhibited superior environmental stability,whereas the Cry1Ab construct caused only slight but ecologically acceptable shifts.These findings support the ecological safety of Bt-transgenic C.bungei and identify Cry9-2 as a particularly favorable candidate for forestry applications.This comparative evaluation of three Cry genes in a tree species provides a framework for future gene-specific biosafety assessments in woody plants.
