Photoperiod-Dependent Nutrient Accumulation in Rice Cultivated in Plant Factories: A Comparative Metabolomic Analysis

Area of Science:

• Agricultural Science
• Metabolomics
• Plant Physiology

Background:

• Plant factories enable controlled, year-round crop production.
• The impact of plant factory conditions on crop metabolism is not fully understood.
• Photoperiod is a critical environmental factor influencing plant growth and development.

Purpose of the Study:

• To investigate the effects of different photoperiods on rice grain metabolomics in a plant factory setting.
• To identify key metabolites affected by photoperiod manipulation.
• To assess the nutritional implications of plant factory cultivation.

Main Methods:

• Cultivation of three rice accessions (KongYu131, HuangHuaZhan, Kam Sweet Rice) in a plant factory.
• Application of two photoperiod treatments: long-day (12h light/12h dark) and short-day (8h light/16h dark).
• Metabolomic analysis of harvested rice grains to quantify 438 metabolites.

Main Results:

• Significant differences in metabolite accumulation were observed between long-day and short-day photoperiods.
• Most metabolites showed higher accumulation under short-day conditions.
• Differentially accumulated metabolites were notably enriched in amino acid and vitamin B6 pathways, with asparagine, pyridoxamine, and pyridoxine being key compounds.

Conclusions:

• Photoperiod significantly influences rice grain metabolomics in plant factories.
• Short-day photoperiods enhance the accumulation of specific amino acids and vitamin B6 in rice.
• This research provides insights into optimizing plant factory conditions for improved rice nutritional quality.