{"title":"Interactions between the nitrogen-fixing cyanobacterium <i>Trichodesmium</i> and siderophore-producing cyanobacterium <i>Synechococcus</i> under iron limitation.","authors":"Xumei Sun, Yan Xiao, Chengwen Yong, Hansheng Sun, Shuangqing Li, Hailong Huang, Haibo Jiang","doi":"10.1093/ismeco/ycae072","DOIUrl":null,"url":null,"abstract":"<p><p>As diazotrophic cyanobacteria of tremendous biomass, <i>Trichodesmium</i> continuously provide a nitrogen source for carbon-fixing cyanobacteria and drive the generation of primary productivity in marine environments. However, ocean iron deficiencies limit growth and metabolism of <i>Trichodesmium</i>. Recent studies have shown the co-occurrence of <i>Trichodesmium</i> and siderophore-producing <i>Synechococcus</i> in iron-deficient oceans, but whether siderophores secreted by <i>Synechococcus</i> can be used by <i>Trichodesmium</i> to adapt to iron deficiency is not clear. We constructed a mutant <i>Synechococcus</i> strain unable to produce siderophores to explore this issue. <i>Synechococcus</i> filtrates with or without siderophores were added into a <i>Trichodesmium</i> microbial consortium consisting of Trichodesmium erythraeum IMS 101 as the dominant microbe with chronic iron deficiency. By analyzing the physiological phenotype, metagenome, and metatranscriptome, we investigated the interactions between the nitrogen-fixing cyanobacterium <i>Tricodesmium</i> and siderophore-producing cyanobacterium <i>Synechococcus</i> under conditions of iron deficiency. The results indicated that siderophores secreted by <i>Synechococcus</i> are likely to chelate with free iron in the culture medium of the <i>Trichodesmium</i> consortium, reducing the concentration of bioavailable iron and posing greater challenges to the absorption of iron by <i>Trichodesmium</i>. These findings revealed the characteristics of iron-competitive utilization between diazotrophic cyanobacteria and siderophore-producing cyanobacteria, as well as potential interactions, and provide a scientific basis for understanding the regulatory effects of nutrient limitation on marine primary productivity.</p>","PeriodicalId":73516,"journal":{"name":"ISME communications","volume":null,"pages":null},"PeriodicalIF":5.1000,"publicationDate":"2024-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11171426/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"ISME communications","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1093/ismeco/ycae072","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2024/1/1 0:00:00","PubModel":"eCollection","JCR":"Q1","JCRName":"ECOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
As diazotrophic cyanobacteria of tremendous biomass, Trichodesmium continuously provide a nitrogen source for carbon-fixing cyanobacteria and drive the generation of primary productivity in marine environments. However, ocean iron deficiencies limit growth and metabolism of Trichodesmium. Recent studies have shown the co-occurrence of Trichodesmium and siderophore-producing Synechococcus in iron-deficient oceans, but whether siderophores secreted by Synechococcus can be used by Trichodesmium to adapt to iron deficiency is not clear. We constructed a mutant Synechococcus strain unable to produce siderophores to explore this issue. Synechococcus filtrates with or without siderophores were added into a Trichodesmium microbial consortium consisting of Trichodesmium erythraeum IMS 101 as the dominant microbe with chronic iron deficiency. By analyzing the physiological phenotype, metagenome, and metatranscriptome, we investigated the interactions between the nitrogen-fixing cyanobacterium Tricodesmium and siderophore-producing cyanobacterium Synechococcus under conditions of iron deficiency. The results indicated that siderophores secreted by Synechococcus are likely to chelate with free iron in the culture medium of the Trichodesmium consortium, reducing the concentration of bioavailable iron and posing greater challenges to the absorption of iron by Trichodesmium. These findings revealed the characteristics of iron-competitive utilization between diazotrophic cyanobacteria and siderophore-producing cyanobacteria, as well as potential interactions, and provide a scientific basis for understanding the regulatory effects of nutrient limitation on marine primary productivity.