A new mechanistic understanding of light-limitation in the seagrass Zostera muelleri

• Published in: Marine environmental research Vol. 134; pp. 55 - 67
• Main Authors: Davey, Peter A., Pernice, Mathieu, Ashworth, Justin, Kuzhiumparambil, Unnikrishnan, Szabó, Milán, Dolferus, Rudy, Ralph, Peter J.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.03.2018; Elsevier BV
• Subjects: Abscisic acid; Carbohydrate metabolism; Carbohydrates; Chlorophyll; Chlorophylls; Chromatography; Composition; Fluorometers; Fluorometry; Gene expression; Gene sequencing; Genes; High-performance liquid chromatography; HPLC; Light; Liquid chromatography; Metabolism; Molecular chains; Nucleic acids; Photons; Photosynthesis; Photosystem II; Pigments; Ribonucleic acid; RNA; RNA sequencing; Sea grasses; Southern Hemisphere; Water column
• ISSN: 0141-1136; 1879-0291
• DOI: 10.1016/j.marenvres.2017.12.012

In this study we investigated the effect of light-limitation (∼20 μmol photons m−2 s−1) on the southern hemisphere seagrass, Zostera muelleri. RNA sequencing, chlorophyll fluorometry and HPLC techniques were used to investigate how the leaf-specific transcriptome drives changes in photosynthesis and photo-pigments in Z. muelleri over 6 days. 1593 (7.51%) genes were differentially expressed on day 2 and 1481 (6.98%) genes were differentially expressed on day 6 of the experiment. Differential gene expression correlated with significant decreases in rETRMax, Ik, an increase in Yi (initial photosynthetic quantum yield of photosystem II), and significant changes in pigment composition. Regulation of carbohydrate metabolism was observed along with evidence that abscisic acid may serve a role in the low-light response of this seagrass. This study provides a novel understanding of how Z. muelleri responds to light-limitation in the marine water column and provides potential molecular markers for future conservation monitoring efforts. •Gene expression leads to changes in the downstream photophysiology of Zostera muelleri.•Abscisic Acid may play a potential role in Z. muelleri in response to light-limitation.•Differentially expressed genes have the potential to be used as molecular markers in future seagrass monitoring programs.