Katja Frede, Sara Winkelmann, Linda Busse & Susanne Baldermann
Published: 21 June 2023 | BMC Plant Biology
Abstract
New vegetable production systems, such as vertical farming, but also well-established in-door production methods led to the implementation of light emitting diodes (LEDs). LEDs are the most important light sources in modern indoor-production systems and offer the possibility for enhancing growth and specific metabolites in planta. Even though the number of studies investigating the effects of LED lighting on vegetable quality has increased, the knowledge about genus variability is limited. In the present study, the effect of different LED spectra on the metabolic and transcriptional level of the carotenoid metabolism in five different Brassica sprouts was investigated. Cruciferous vegetables are one of the main food crops worldwide. Pak choi (Brassica rapa ssp. chinensis), cauliflower (Brassica oleracea var. botrytis), Chinese cabbage (Brassica rapa ssp. pekinensis), green kale (Brassica oleracea ssp. sabellica) and turnip cabbage (Brassica oleracea spp. gongylodes) sprouts were grown under a combination of blue & white LEDs, red & white LEDs or only white LEDs to elucidate the genus-specific carotenoid metabolism.
Spectral distribution of (a) white, (b) blue & white and (c) red & white LEDs with filter used in the experiments
The effectiveness of this method is demonstrated by testing and recovering the spectrum of a yellow LED subjected to other light sources in outdoor conditions. Additionally, it was possible to demonstrate the method’s applicability for the spectroscopic analysis of gold nanoparticles in outdoor conditions. These results suggest that the proposed technique can be helpful for a wide range of optical measurement techniques, even in challenging lighting conditions.
Results
Genus-specific changes in plant weight and on the photosynthetic pigment levels as well as transcript levels have been detected. Interestingly, the transcript levels of the three investigated carotenoid biosynthesis genes phytoene synthase (PSY), β-cyclase (βLCY) and β-carotene hydroxylase (βOHASE1) were increased under the combination of blue & white LEDs in the majority of the Brassica sprouts. However, only in pak choi, the combination of blue & white LEDs enhanced the carotenoid levels by 14% in comparison to only white LEDs and by ~ 19% in comparison to red & white LEDs.
