Molecular mechanisms of the eukaryotic phytoplankton physiological response to stressors in the northern Adriatic

Knjaz, Mia (2025) Molecular mechanisms of the eukaryotic phytoplankton physiological response to stressors in the northern Adriatic. Doctoral thesis, Prirodoslovni fakultet Sveučilišta u Zagrebu.

PDF - Published Version - other
Download (10MB)

Abstract

The northern Adriatic is a dynamic marine ecosystem where various environmental pressures, in particular phosphorus limitation, characterise phytoplankton communities. Previous studies have established annual succession patterns and identified physiological responses of individual diatom species to phosphorus limitation. However, research based on molecular methods remains scarce, and the molecular mechanisms underlying these physiological responses are still poorly understood. This study is the first to apply RNA sequencing-based molecular methods, transcriptomics, and metatranscriptomics, to investigate the molecular mechanisms of the physiological response of both individual species and whole phytoplankton communities of the northern Adriatic under environmental stress, with a focus on phosphorus limitation. A publicly available reference transcriptome database of northern Adriatic diatoms, grown under experimental conditions simulating variable phosphorus availability, has been established. Gene expression analyses of metabolic pathways and phosphorus-related genes revealed species-specific molecular mechanisms of adaptation to phosphorus scarcity. A one-year monitoring of the phytoplankton community taxonomic and functional dynamics uncovered clear seasonal patterns determined by environmental factors, in particular the availability of phosphorus and silicon, as well as interactions between species. These findings enabled the identification of previously unknown molecular mechanisms of phytoplankton responses to various ecological pressures.

Item Type:

Thesis (Doctoral thesis)

Uncontrolled Keywords:

phytoplankton; northern Adriatic; phosphorus limitation; transcriptomics; metatranscriptomics

Subjects:

NATURAL SCIENCES
NATURAL SCIENCES > Interdisciplinary Natural Sciences
NATURAL SCIENCES > Interdisciplinary Natural Sciences > Marine Science

Divisions:

Center for Marine Research

Projects: