Molecular mechanisms of the coordination between astaxanthin and fatty acid biosynthesis in Haematococcus pluvialis (Chlorophyceae)

Guanqun Chen, Baobei Wang, Danxiang Han, Milton Sommerfeld, Yinghua Lu, Feng Chen, Qiang Hu

Research output: Contribution to journalArticle

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Abstract

Astaxanthin, a red ketocarotenoid with strong antioxidant activity and high commercial value, possesses important physiological functions in astaxanthin-producing microalgae. The green microalga Haematococcus pluvialis accumulates up to 4% fatty acid-esterified astaxanthin (by dry weight), and is used as a model species for exploring astaxanthin biosynthesis in unicellular photosynthetic organisms. Although coordination of astaxanthin and fatty acid biosynthesis in a stoichiometric fashion was observed in H. pluvialis, the interaction mechanism is unclear. Here we dissected the molecular mechanism underlying coordination between the two pathways in H. pluvialis. Our results eliminated possible coordination of this inter-dependence at the transcriptional level, and showed that this interaction was feedback-coordinated at the metabolite level. In vivo and in vitro experiments indicated that astaxanthin esterification drove the formation and accumulation of astaxanthin. We further showed that both free astaxanthin biosynthesis and esterification occurred in the endoplasmic reticulum, and that certain diacylglycerol acyltransferases may be the candidate enzymes catalyzing astaxanthin esterification. A model of astaxanthin biosynthesis in H. pluvialis was subsequently proposed. These findings provide further insights into astaxanthin biosynthesis in H. pluvialis. Significance Statement The molecular mechanism underlying the coordination between fatty acid biosynthesis and astaxanthin biosynthesis in H. pluvialis was dissected, which provided further insights into astaxanthin biosynthesis in H. pluvialis.

Original languageEnglish (US)
Pages (from-to)95-107
Number of pages13
JournalPlant Journal
Volume81
Issue number1
DOIs
StatePublished - Jan 1 2015

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Keywords

  • Haematococcus pluvialis
  • acyl CoA diacylglycerol acyltransferase
  • carotenoid
  • fatty acid biosynthesis
  • gene transcription
  • metabolic coordination
  • microalgae

ASJC Scopus subject areas

  • Genetics
  • Plant Science
  • Cell Biology

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