Transcriptional responses of Trichodesmium to natural inverse gradients of Fe and P availability

Cerdan-Garcia, E, Baylay, A, Polyviou, D, Woodward, EMS, Wrightson, L, Mahaffey, C, Lohan, MC, Moore, CM, Bibby, T.S and Robidart, J.C 2021 Transcriptional responses of Trichodesmium to natural inverse gradients of Fe and P availability. ISME Journal - Multidisciplinary Journal of Microbial Ecology.

Cerdan-Garcia_2021 Published.pdf - Accepted Version
Available under License Creative Commons Attribution.

Download (1MB) | Preview


The filamentous diazotrophic cyanobacterium Trichodesmium is responsible for a significant fraction of marine di-nitrogen (N2) fixation. Growth and distribution of Trichodesmium and other diazotrophs in the vast oligotrophic subtropical gyres is influenced by iron (Fe) and phosphorus (P) availability, while reciprocally influencing the biogeochemistry of these nutrients. Here we use observations across natural inverse gradients in Fe and P in the North Atlantic subtropical gyre (NASG) to demonstrate how Trichodesmium acclimates in situ to resource availability. Transcriptomic analysis identified progressive upregulation of known ironstress biomarker genes with decreasing Fe availability, and progressive upregulation of genes involved in the acquisition of diverse P sources with decreasing P availability, while genes involved in N2 fixation were upregulated at the intersection under moderate Fe and P availability. Enhanced N2 fixation within the Fe and P co-stressed transition region was also associated with a distinct, consistent metabolic profile, including the expression of alternative photosynthetic pathways that potentially facilitate ATP generation required for N2 fixation with reduced net oxygen production. The observed response of Trichodesmium to availability of both Fe and P supports suggestions that these biogeochemically significant organisms employ unique molecular, and thus physiological responses as adaptations to specifically exploit the Fe and P co-limited niche they construct.

Item Type: Publication - Article
Subjects: Biology
Marine Sciences
Divisions: Plymouth Marine Laboratory > Science Areas > Marine Biochemistry and Observations
Depositing User: Malcolm Woodward
Date made live: 22 Mar 2022 10:17
Last Modified: 22 Mar 2022 10:17

Actions (login required)

View Item View Item