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%，下沉行为是一个重要的物种特有的属性，可以确定群落组成，聚集体形成和物质损失到深度的量。虽然硅藻不能游泳，但它们远不是被动的，它们在很长一段时间内控制着它们的下沉速度，以响应环境因素，如营养浓度，辐照度和温度以及生物因素，如繁殖状态。硅藻下沉的早期研究表明，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时间尺度上控制它们的下沉速度，表现出最近发现的不稳定下沉行为。迄今为止，硅藻悬浮液的研究主要使用散装测量，如沉降柱（SETCOLS），由于易于测量和假设散装率充分捕捉这组的基本特征。我们提供的证据表明，这种假设是不合理的，并提出了一系列的实验室实验，使用先进的光学技术，生理工具，测量单细胞周围的过程和数值方法来研究分类和形态的变化，在一系列的环境条件下不稳定的下沉，并检查所观察到的差异的影响。该项目将利用跨学科合作，涉及创新的光学技术，先进的细胞生理学工具和数值建模方法，以表征硅藻悬浮液在单个细胞水平的特性。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钟内变化几个数量级。我们将讨论瞬时速度控制行为的几个方面，以确定非定常下沉的适应意义。这一新的观察表明，扩散限制运输模型需要修改，以适应物种特异性差异。我们将使用来自各种物种和环境条件的单个细胞水平实验数据来告知3D数值模型，该模型将用于表征硅藻中的适应性意义（如果有的话）以及为什么它可能被限制在某些分类组中。

项目成果

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

• DOI: 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