Mechanisms of Trichodesmium demise within the New Caledonian lagoon during the VAHINE mesocosm experiment
Mechanisms of Trichodesmium demise within the New Caledonian lagoon during the VAHINE mesocosm experiment
复制标题
VAHINE 中生态实验期间新喀里多尼亚泻湖内毛藻的死亡机制
DOI：
10.5194/bg-13-4187-2016
复制
发表时间：
2016
期刊：
影响因子：
4.9
通讯作者：
I. Berman‐Frank
中科院分区：
文献类型：
--
作者：
D. Spungin;U. Pfreundt;H. Berthelot;S. Bonnet;D. AlRoumi;F. Natale;W. Hess;K. Bidle;I. Berman‐Frank
抽象的。全球重要的海洋重氮蓝藻Trichodesmium是丰富的新喀里多尼亚泻湖（西南太平洋）在南春季/夏季。我们调查了细胞过程介导的Trichodesmium死亡率从大的表面积累（水华）在泻湖。在表面积累时收集束毛藻细胞（和相关的微生物群），封闭在模拟的环境条件下，并随时间取样以阐明快速生物质死亡（> 90%的生物质在124小时内崩溃）的应激源和亚细胞基础。毛束藻生物量，0，8和22小时后，孵化的表面积累的Metatranscriptomic分析，表现出上调所需的基因的表达，以增加磷（P）和铁（Fe）的可用性和运输，而负责营养储存的基因下调。总病毒丰度在整个实验中振荡，并显示与束毛藻生物量的发展或消亡没有显着的关系。增强的半胱天冬酶的特异性活性和一套metacaspase基因的上调表达，作为束毛藻生物量崩溃，暗示自催化程序性细胞死亡（PCD）的机械原因。同时，与浮力和气泡生产相关的基因强烈下调，伴随着生产增加和高浓度的透明外聚合物颗粒（TEP）。快速，PCD介导的，下降的束毛藻的生物量，我们观察到从我们的孵化，平行的死亡率报告从束毛藻开花原位。我们的研究结果表明，无论最终的因素，PCD介导的死亡束毛藻可以迅速终止开花，促进聚集，加快垂直通量的深度。
Abstract. The globally important marine diazotrophic cyanobacterium Trichodesmium is abundant in the New Caledonian lagoon (southwestern Pacific Ocean) during austral spring/summer. We investigated the cellular processes mediating Trichodesmium mortality from large surface accumulations (blooms) in the lagoon. Trichodesmium cells (and associated microbiota) were collected at the time of surface accumulation, enclosed under simulated ambient conditions, and sampled over time to elucidate the stressors and subcellular underpinning of rapid biomass demise (> 90 % biomass crashed within ∼ 24 h). Metatranscriptomic profiling of Trichodesmium biomass, 0, 8 and 22 h after incubations of surface accumulations, demonstrated upregulated expression of genes required to increase phosphorus (P) and iron (Fe) availability and transport, while genes responsible for nutrient storage were downregulated. Total viral abundance oscillated throughout the experiment and showed no significant relationship with the development or demise of the Trichodesmium biomass. Enhanced caspase-specific activity and upregulated expression of a suite of metacaspase genes, as the Trichodesmium biomass crashed, implied autocatalytic programmed cell death (PCD) as the mechanistic cause. Concurrently, genes associated with buoyancy and gas vesicle production were strongly downregulated concomitant with increased production and high concentrations of transparent exopolymeric particles (TEP). The rapid, PCD-mediated, decline of the Trichodesmium biomass, as we observed from our incubations, parallels mortality rates reported from Trichodesmium blooms in situ. Our results suggest that, whatever the ultimate factor, PCD-mediated death in Trichodesmium can rapidly terminate blooms, facilitate aggregation, and expedite vertical flux to depth.
全球重要的海洋固氮菌毛藻对亚磷酸盐的利用。
影响因子：
3.3
作者：
Polyviou D
通讯作者：
Polyviou D
影响因子：
11.4
作者：
Luo, Y. -W.;Doney, S. C.;Zehr, J. P.
通讯作者：
Zehr, J. P.