Lettuce can modulate its metabolism according to light intensity and quality

May 21, 2018

Customizing useful metabolite productivity with narrow-band LED lighting

RIKEN CSRS researchers have become the first in the world to apply integrated omics analysis to clarify the differences in metabolites for red-leaf lettuce cultivated under artificial light conditions. The study was done in collaboration with the University of Tsukuba, the Central Research Institute of Electric Power Industry and the UC Davis Genome Center.

Three kinds of mass spectrometry platforms were used to investigate metabolite accumulation patterns (metabolite profiles) for different combinations of four types of light qualities at two intensities and two irradiation periods. Researchers found that for short irradiation periods, differences in light intensity contributed the most differences in lettuce metabolite profiles, while for longer irradiation periods the type of light had the greatest effect.

Detailed analysis of metabolome data showed that metabolite profiles for carbohydrates and amino acids, which affect taste, are influenced by all three factors.

Researchers then carried out RNA-Seq analysis using a next-generation sequencer capable of comprehensively analyzing gene expression patterns (transcript profiles), which revealed that different light qualities have different effects on the metabolic network. Additionally, of different metabolite groups in red-leaf lettuce, an integrated analysis of metabolites and transcripts for the biosynthetic pathways for phenylpropanoids and flavonoids (which are antioxidants) indicated that flavonols are specifically induced by blue light, while the accumulation of chlorogenates gradually decreases with longer light wavelengths.

These results are expected to contribute to the development of technologies for controlling metabolites governing the taste and nutritional content of vegetables produced in plant factories.

Original article
Scientific Reports doi:10.1038/s41598-018-25686-0
K. Kitazaki, A. Fukushima, R. Nakabayashi, Y. Okazaki, M. Kobayashi, T. Mori, T. Nishizawa, S. Reyes-Chin-Wo, R. W. Michelmore, K. Saito, K. Shoji, M. Kusano,
"Metabolic reprogramming in leaf lettuce grown under different light quality and intensity conditions using narrow-band LEDs".
Miyako Kusano; Senior Visiting Scientist
Metabolomics Research Group
Atsushi Fukushima; Research Scientist
Metabolome Informatics Research Team