Multi-omics analyses to assess the effects of multi-layer cultivation with supplemental LED lighting on potato yield...

Integrating a vertical layout into greenhouse allows space-efficient cultivation and energy saving; however, shading of the lower canopy makes supplemental artificial lighting necessary. Here, we investigated the effect of red-blue LED supplementation in a vertical greenhouse system for potato cultivation on plant growth, tuber yield, and mineral and metabolite composition, compared to full natural sunlight as a control. Cultivation units were designed to simulate a multiple-layer growing system, in which the uppermost level received only natural light, while LEDs integrated reduced light intensity in the shaded lower level up to 300 µmol m^-2 s^-1. Despite the lower daily light integral, LED-supplemented plants showed higher photosynthetic activity and slower decline in leaf chlorophyll content over time, which contributed to higher tuber yield compared to the control. Multi-omics analyses on tuber tissues revealed coordinated metabolic reprogramming. Transcriptomic data showed up-regulation of genes involved in photosynthesis, sugar metabolism, and polyamine biosynthesis in LED-treated plants, together with down-regulation of stress-related genes. Proteomic and metabolomic profiling partially confirmed such trends, highlighting a down-representation of stress-responsive proteins as well as reduced levels of polyphenols, glycoalkaloids and enzymes related to their biosynthesis, highlighting an overall metabolic shift toward an attenuated stress response. In parallel, plants grown under LED lighting showed augmented content of nitrogen, polyamines and some precursor amino acids in the corresponding tubers, qualifying their nutritional characteristics. These results provide mechanistic insights into the relationship between potato plants artificial lighting and molecular reprogramming with the aim of improving crop production and food quality.