NSFGEO-NERC: Novel imaging, physiology and numerical approaches for understanding biologically mediated, unsteady sinking in marine diatoms

NSFGEO-NERC：用于了解海洋硅藻生物介导的不稳定下沉的新颖成像、生理学和数值方法

• 批准号: NE/V013343/1
• 负责人: Glen Wheeler
• 金额: $ 21.68万
• 依托单位: Marine Biological Association of the United Kingdom
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FV013343%2F1
• 关键词: NSFGEO; NERC; Novel; imaging; physiology

Diatoms account for up to 40% of oceanic primary production sinking behavior is an important species-specific property that can determine the community composition, aggregate formation and the amount of material lost to depth. Although they are unable to swim, diatoms are far from passive, controlling their sinking speeds over long time scales in response to environmental factors, such as nutrient concentration, irradiance, and temperature and biological factors, such as reproductive state. Early work on diatom sinking demonstrated the capacity of diatoms to regulate their buoyancies over hours to days in response to changing environmental conditions. However, some species can also control their sinking speeds over much shorter time scales of seconds, performing a recently discovered unsteady sinking behavior. To date, diatom suspension studies have largely used bulk measurements such as settling columns (SETCOLSs) due to the ease of measurement and assumption that bulk rates adequately capture the essential characteristics of this group. We offer evidence that this assumption is not justified and propose a series of laboratory experiments using advanced optical techniques, physiological tools that measure processes around single cells and numerical approaches to investigate taxonomic and morphological variability in unsteady sinking over a range of environmental conditions and examine the implications the observed differences. This project will leverage an interdisciplinary collaboration involving innovative optical techniques, advanced cell physiology tools and numerical modeling approaches to characterize diatom suspension properties at the individual cell level. The shift from time-averaged sinking measurements to small time scales has indicated that sinking speeds can vary orders of magnitude over seconds. We will address several aspects of instantaneous velocity control behavior in order to determine the adaptive significance of unsteady sinking. This novel observation suggests that models of diffusion limited transport need to be revised in order to accommodate species-specific differences. We will use individual cell level experimental data from a variety of species and environmental conditions to inform 3D numerical models which will be used to characterize what, if any, adaptive significance unsteady sinking in diatoms has and why it may be constrained to certain taxonomic groups.

硅藻占海洋初级生产力的 40%，下沉行为是一种重要的物种特异性特性，可以决定群落组成、聚集体形成和深度流失的物质量。尽管硅藻无法游泳，但它们远非被动，它们会在很长一段时间内控制其下沉速度，以响应环境因素（例如营养物浓度、辐照度和温度）以及生物因素（例如繁殖状态）。早期关于硅藻沉降的研究表明，硅藻有能力在数小时至数天内调节其浮力，以应对不断变化的环境条件。然而，一些物种也可以在更短的秒级时间内控制其下沉速度，执行最近发现的不稳定下沉行为。迄今为止，硅藻悬浮液研究主要使用沉降柱 (SETCOLS) 等批量测量，因为测量方便并且假设批量速率充分捕获了该组的基本特征。我们提供的证据表明这种假设是不合理的，并提出了一系列实验室实验，使用先进的光学技术、测量单细胞周围过程的生理工具和数值方法来研究一系列环境条件下不稳定下沉的分类和形态变异性，并检查影响观察到的差异。该项目将利用涉及创新光学技术、先进细胞生理学工具和数值建模方法的跨学科合作来表征单个细胞水平的硅藻悬浮特性。从时间平均下沉测量到小时间尺度的转变表明，下沉速度可以在几秒内发生数量级的变化。我们将讨论瞬时速度控制行为的几个方面，以确定非稳态下沉的自适应意义。这一新颖的观察结果表明，需要修改扩散限制运输模型，以适应物种特异性的差异。我们将使用来自各种物种和环境条件的个体细胞水平实验数据来为 3D 数值模型提供信息，该模型将用于描述硅藻不稳定下沉的适应性意义（如果有的话）以及为什么它可能仅限于某些分类群。

项目成果

Regulation and integration of membrane transport in marine diatoms.

海洋硅藻膜运输的调节和整合。

• DOI: 10.1016/j.semcdb.2022.03.006
• 发表时间: 2022-03-01
• 期刊: Seminars in cell & developmental biology
• 影响因子: 7.3
• 作者: C. Brownlee;Katherine E. Helliwell;Y. Meeda;D. McLachlan;Eleanor A. Murphy;Glen L. Wheeler
• 通讯作者: Glen L. Wheeler

Cold-induced [Ca2+]cyt elevations function to support osmoregulation in marine diatoms.

寒冷诱导的 [Ca2+] 细胞色素升高有助于支持海洋硅藻的渗透调节。

• DOI: http://dx.10.1093/plphys/kiac324
• 发表时间: 2022-09-28
• 期刊: Plant physiology
• 影响因子: 7.4
• 作者: Kleiner, Friedrich H.;Helliwell, Katherine E.;Chrachri, Abdul;Hopes, Amanda;Parry-Wilson, Hannah;Gaikwad, Trupti;Mieszkowska, Nova;Mock, Thomas;Wheeler, Glen L.;Brownlee, Colin
• 通讯作者: Brownlee, Colin