Back to Search
Start Over
Growth and Bioactive Compound Synthesis in Cultivated Lettuce Subject to Light-quality Changes
- Source :
- HortScience. 52:584-591
- Publication Year :
- 2017
- Publisher :
- American Society for Horticultural Science, 2017.
-
Abstract
- This study aimed to determine the effect of changes in light quality on the improvement of growth and bioactive compound synthesis in red-leaf lettuce (Lactuca sativa L. ‘Sunmang’) grown in a plant factory with electrical lighting. Lettuce seedlings were subjected to 12 light treatments combining five lighting sources: red (R; 655 nm), blue (B; 456 nm), and different ratios of red and blue light combined with three light-emitting diodes [LEDs (R9B1, R8B2, and R6B4)]. Treatments were divided into control (continuous irradiation of each light source for 4 weeks), monochromatic (changing from R to B at 1, 2, or 3 weeks after the onset of the experiments), and combined (changing from R9B1 to R8B2 or R6B4 at 2 or 3 weeks after the onset of the experiments). Growth and photosynthetic rates of lettuce increased with increasing ratios of red light, whereas chlorophyll and antioxidant phenolic content decreased with increasing ratios of red light. Individual phenolic compounds, including chlorogenic, caffeic, chicoric, and ferulic acids, and kaempferol, showed a similar trend to that of total phenolics. Moreover, transcript levels of phenylalanine ammonia-lyase (PAL) and chalcone synthase (CHS) genes were rapidly upregulated by changing light quality from red to blue. Although the concentration of bioactive compounds in lettuce leaves enhanced with blue light, their contents per lettuce plant were more directly affected by red light, suggesting that biomass as well as bioactive compounds’ accumulation should be considered to enhance phytochemical production. In addition, results suggested that growth and antioxidant phenolic compound synthesis were more sensitive to monochromatic light than to combined light variations. In conclusion, the adjustment of light quality at a specific growth stage should be considered as a strategic tool for improving crop yield, nutritional quality, or both in a plant factory with electrical lighting.
- Subjects :
- 0106 biological sciences
04 agricultural and veterinary sciences
Horticulture
Biology
01 natural sciences
Bioactive compound
Light quality
chemistry.chemical_compound
chemistry
Cultivated lettuce
Botany
040103 agronomy & agriculture
0401 agriculture, forestry, and fisheries
010606 plant biology & botany
Subjects
Details
- ISSN :
- 23279834 and 00185345
- Volume :
- 52
- Database :
- OpenAIRE
- Journal :
- HortScience
- Accession number :
- edsair.doi...........ed9f047d30b805801e4f30c73fd6332f