Shaping kale morphology and physiology using precision LED light recipes

Light serves as a fundamental factor in plant development, both as an energy source and as an environmental cue. With the advent of light-emitting diode (LED) technology, light can be precisely manipulated to influence key plant traits. Here, we assess effects of light intensity and spectral composition on the growth and physiology of kale (Brassica oleracea). Kale is known for its phenotypic plasticity and nutritional composition, making it a crop well suited for indoor cultivation either as microgreens or as large leafy plants. Here, we employ a combination of advanced phenotyping, computer vision, GC-MS metabolomics, and LC-MS-based quantitative proteomics to characterize the molecular changes that underpin light-dictated differences in the growth and metabolism of two different commercially grown kale cultivars under different light intensities and spectral compositions. We identify time-of-day- and cultivar-specific light intensity- and spectral composition-induced changes related to growth, shade avoidance, photosynthesis, and several aspects of nutritional composition, including amino acids, glucosinolates, and carotenoids. Our results offer a key resource to the plant community and demonstrate the translational potential of light manipulation in tailoring kale growth and nutritional content for enhanced crop productivity and/or health benefits, while simultaneously offering a more cost-effective solution for contemporary agricultural challenges.