Antioxidant capacity reduced in scallions grown under elevated CO 2 independent of assayed light intensity

Lanfang H. Levine, Paul W. Paré

Research output: Contribution to journalArticlepeer-review

23 Scopus citations


Long-duration manned space missions mandate the development of a sustainable life support system and effective countermeasures against damaging space radiation. To mitigate the risk of inevitable exposure to space radiation, cultivation of fresh fruits and vegetables rich in antioxidants is an attractive alternative to pharmacological agents. However it has yet to be established whether antioxidant properties of crops can be preserved or enhanced in a space environment where environmental conditions differ from that which plants have acclimated to on earth. Scallion (Allium fistulosum) rich in antioxidant vitamins C and A, and flavonoids was used as a model plant to study the impact of a range of CO 2 concentrations and light intensities that are likely encountered in a space habitat on food quality traits. Scallions were hydroponically grown in controlled environmental chambers under a combination of 3 CO 2 concentrations of 400, 1200 and 4000 μmol mol -1 and 3 light intensity levels of 150, 300, 450 μmol m -2 s -1 . Total antioxidant activity (TAA) of scallion extracts was determined using a radical cation scavenging assay. Both elevated CO 2 and increasing light intensity enhanced biomass accumulation, but effects on TAA (based on dry weight) differed. TAA was reduced for plants grown under elevated CO 2 , but remained unchanged with increases in light intensity. Elevated CO 2 stimulated greater biomass production than antioxidants, while an increase in photosynthetic photo flux promoted the synthesis of antioxidant compounds at a rate similar to that of biomass. Consequently light is a more effective stimulus than CO 2 for antioxidant production.

Original languageEnglish
Pages (from-to)887-894
Number of pages8
JournalAdvances in Space Research
Issue number8
StatePublished - Oct 15 2009


  • Elevated [CO ]
  • Scallion (Allium fistulosum L.)
  • Total antioxidant activity (TAA)
  • Total phenolics


Dive into the research topics of 'Antioxidant capacity reduced in scallions grown under elevated CO <sub>2</sub> independent of assayed light intensity'. Together they form a unique fingerprint.

Cite this