Metabolite Profiling and Integrative Modeling Reveal Metabolic Constraints for Carbon Partitioning under Nitrogen Starvation in the Green Algae Haematococcus pluvialis

The green alga Hematococcus pluvialis accumulates large amounts of the antioxidant astaxanthin under inductive stress conditions, such as nitrogen starvation. The response to nitrogen starvation and high light leads to the accumulation of carbohydrates and fatty acids as well as increased activity o...

Full description

Saved in:
Bibliographic Details
Published in:The Journal of biological chemistry 2014-10, Vol.289 (44), p.30387-30403
Main Authors: Recht, Lee, Töpfer, Nadine, Batushansky, Albert, Sikron, Noga, Gibon, Yves, Fait, Aaron, Nikoloski, Zoran, Boussiba, Sammy, Zarka, Aliza
Format: Article
Language:English
Subjects:
Carbohydrate Metabolism
Carotenoids - metabolism
Chlorophyta - metabolism
Chlorophyta - radiation effects
Citric Acid Cycle
Cluster Analysis
Computational Biology
Computer Simulation
Fatty Acids - biosynthesis
Light
Metabolic Flux Analysis
Metabolome
Nitrogen - metabolism
Starch - metabolism
Stress, Physiological
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The green alga Hematococcus pluvialis accumulates large amounts of the antioxidant astaxanthin under inductive stress conditions, such as nitrogen starvation. The response to nitrogen starvation and high light leads to the accumulation of carbohydrates and fatty acids as well as increased activity of the tricarboxylic acid cycle. Although the behavior of individual pathways has been well investigated, little is known about the systemic effects of the stress response mechanism. Here we present time-resolved metabolite, enzyme activity, and physiological data that capture the metabolic response of H. pluvialis under nitrogen starvation and high light. The data were integrated into a putative genome-scale model of the green alga to in silico test hypotheses of underlying carbon partitioning. The model-based hypothesis testing reinforces the involvement of starch degradation to support fatty acid synthesis in the later stages of the stress response. In addition, our findings support a possible mechanism for the involvement of the increased activity of the tricarboxylic acid cycle in carbon repartitioning. Finally, the in vitro experiments and the in silico modeling presented here emphasize the predictive power of large scale integrative approaches to pinpoint metabolic adjustment to changing environments.
ISSN:0021-9258
1083-351X
DOI:10.1074/jbc.M114.555144