Projects per year
Abstract
Seagrasses thrive in anoxic sediments where sulphide can accumulate to phytotoxic levels. So how do seagrasses persist in this environment? Here, we propose that radial oxygen loss (ROL) from actively growing root tips protects seagrasses from sulphide intrusion not only by abiotically oxidising sulphides in the rhizosphere of young roots, but also by influencing the abundance and spatial distribution of sulphate-reducing and sulphide-oxidising bacteria. We used a novel multifaceted approach combining imaging techniques (confocal fluorescence in situ hybridisation, oxygen planar optodes, and sulphide diffusive gradients in thin films) with microbial community profiling to build a complete picture of the microenvironment of growing roots of the seagrasses Halophila ovalis and Zostera muelleri. ROL was restricted to young root tips, indicating that seagrasses will have limited ability to influence sulphide oxidation in bulk sediments. On the microscale, however, ROL corresponded with decreased abundance of potential sulphate-reducing bacteria and decreased sulphide concentrations in the rhizosphere surrounding young roots. Furthermore, roots leaking oxygen had a higher abundance of sulphide-oxidising cable bacteria; which is the first direct observation of these bacteria on seagrass roots. Thus, ROL may enhance both abiotic and bacterial sulphide oxidation and restrict bacterial sulphide production around vulnerable roots, thereby helping seagrasses to colonise sulphide-rich anoxic sediments.
Original language | English |
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Pages (from-to) | 707-719 |
Number of pages | 13 |
Journal | ISME Journal |
Volume | 13 |
Issue number | 3 |
Early online date | 23 Oct 2018 |
DOIs | |
Publication status | Published - 1 Mar 2019 |
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Dive into the research topics of 'Oxygen loss from seagrass roots coincides with colonisation of sulphide-oxidising cable bacteria and reduces sulphide stress'. Together they form a unique fingerprint.Projects
- 3 Finished
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Crops for a phosphorus-scarce future: plant adaptation to fluctuating phosphorus availability
Ryan, M. (Investigator 01)
ARC Australian Research Council
1/01/14 → 31/12/18
Project: Research
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Overcoming Critical Recruitment Bottlenecks Limiting Seedling Establishment in Degraded Seagrass Ecosystems: A Systems Approach to Restoration
Kendrick, G. (Chief Investigator), Duarte, C. (Chief Investigator), Merritt, D. (Chief Investigator), Orth, R. (Chief Investigator), Broenland, E. (Chief Investigator), Williams, M. (Chief Investigator) & Dixon, K. (Chief Investigator)
ARC Australian Research Council
1/01/13 → 31/12/15
Project: Research
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Ecological and Genetic Connectivity in Seagrasses: The Role of Sexual Reproduction, Dispersal and Recruitment on Meadow Restoration
Kendrick, G. (Investigator 01), Krauss, S. (Investigator 02) & Lowe, R. (Investigator 03)
ARC Australian Research Council
1/01/13 → 31/07/16
Project: Research