Metabolic acclimation to excess light intensity in Chlamydomonas reinhardtii

Abstract

There are several well-described acclimation responses to excess light in green algae but the effect on metabolism has not been thoroughly investigated. This study examines the metabolic changes during photoacclimation to high-light (HL) stress in Chlamydomonas reinhardtii using nuclear magnetic resonance and mass spectrometry. Using principal component analysis, a clear metabolic response to HL intensity was observed on global metabolite pools, with major changes in the levels of amino acids and related nitrogen metabolites. Amino acid pools increased during short-term photoacclimation, but were especially prominent in HL-acclimated cultures. Unexpectedly, we observed an increase in mitochondrial metabolism through downstream photorespiratory pathways. The expression of two genes encoding key enzymes in the photorespiratory pathway, glycolate dehydrogenase and malate synthase, were highly responsive to the HL stress. We propose that this pathway contributes to metabolite pools involved in nitrogen assimilation and may play a direct role in photoacclimation. Our results suggest that primary and secondary metabolism is highly pliable and plays a critical role in coping with the energetic imbalance during HL exposure and a necessary adjustment to support an increased growth rate that is an effective energy sink for the excess reducing power generated during HL stress.

Glycolate from microalgae: an efficient carbon source for biotechnological applications

“…Particularly, the hexokinase is an important sensing and signalling element (reviewed in Rolland et al ., ). To our knowledge, the described effect of metabolically highly active but not growing cells was not observed before and could contribute to the interpretation of the function of photorespiration and to the regulation cell growth in unicellular algae (Davis et al ., ).…”

The effect of salinity concentration on algal biomass production and nutrient removal from municipal wastewater by Dunaliella salina

“…These experiments further illustrated that many microalgae species can survive and grow well in MW conditions. Besides, each strain has its own characteristics and different responses to nutrient removals according to their metabolic pathways and nutrient requirements for cell growth . This study provides evidence for achieving multiple benefits, at least, wastewater bioremediation and mass production of microalgae.…”

Galanthamine, an anti-cholinesterase drug, effects plant growth and development inArtemisia tridentataNutt. via modulation of auxin and neurotransmitter signaling

“…Some researchers are using a strictly targeted approach with quantification of known compounds using authenticated standards and spectral libraries sometimes associated with genomic or proteomic data. 47 Other researchers are using the genomic or proteomic data as chemical leads in a pseudo-untargeted approach that quantifies known compounds from other species but that have not previously been described in the species of interest. These data may be mapped in association with the genomic data for compound and pathway discovery but are not truly untargeted analyses.…”