大老2單機遊戲-貴州衝進水庫大巴內有高考學生
Plant Physiology:紅藻□類生物合成TPS□與陸地植物不一樣Terpene Biosynthesis in Red Algae is Catalyzed by Microbial Type but not Typical Plant Terpene SynthasesFirst author: Guo Wei; Affiliations: University of Tennessee (田納西大學): Tennessee錛 USACorresponding author: Feng ChenRed algae (Rhodophyta) and land plants belong to the monophyletic clade Archaeplastida and taxa of both groups are rich producers of terpene secondary metabolites. The terpene carbon skeletons of land plants are made by two types of terpene synthases: typical plant terpene synthases and microbial-type terpene synthases (MTPSLs); however錛 terpene biosynthesis in red algae is poorly understood. By systematic sequence analysis of seven genomes and 34 transcriptomes of red algae錛 MTPSL homologs were identified within one genome and two transcriptomes錛 whereas no homolog of typical plant terpene synthase genes was found. Phylogenetic analysis showed red algae MTPSLs group with bacterial terpene synthases. Analysis of the genome assembly and characterization of neighboring genes demonstrated red algal MTPSLs to be bona fide red algal genes錛 and not microbial contaminants. MTPSL genes from Porphyridium purpureum and Erythrolobus australicus were characterized via heterologous expression in Escherichia coli and demonstrated to have sesquiterpene synthase activities. We detected a number of volatile sesquiterpenes in the headspace of P. purpureum and E. australicus cultures錛 most identical to the in vitro products of the respective MTPSLs. Expression of the MTPSL gene in P. purpureum was found to be induced by methyl jasmonate錛 suggesting a role for this gene in host defense. In summary錛 this study indicates that the formation of terpene carbon skeletons in red algae is carried out by MTPSLs that are phylogenetically unrelated to typical plant terpene synthases錛 and most likely originated in Rhodophyta via horizontal gene transfer from bacteria.紅藻和陸地植物屬于單系起源的原始色素體生物Archaeplastida,這兩者所包含的物種均富含□類次生代謝物。陸地植物□類物質的碳骨架由兩種類型的□類合□合成,一種是典型的植物□類合□,另一種是微生物類□類合□MTPSL;然而,紅藻中的□類生物合成還不是很清楚。通過7個紅藻基因組和34個紅藻轉錄組的系統序列分析,