From Sunlight to Plant Health: Decoding Metabolic Responses

Carmen Arena^1*Luigi Gennaro Izzo^2*Marina López-Pozo^3*

• ¹Department of Biology, University of Naples Federico II, Naples, Italy
• ²Department of Agricultural Sciences, University of Naples Federico II, Portici, Italy
• ³Department of Ecology & Evolutionary Biology, University of Colorado Boulder, Boulder, United States

The articles collected in this Research Topic collectively illustrate how light quality and quantity act 24 as powerful modulators of plant growth, shaping their metabolism through a complex network of 25 biochemical, transcriptional, and hormonal pathways. These contributions highlight that deciphering 26 light-driven metabolic responses requires integrative approaches spanning from molecular signaling to 27 whole-plant performance and ecosystem-level implications. 28A compelling example of this multi-scale inquiry is presented in the original research by Menicucci et 29 al. (2025), who investigated the impact of specific LED light spectra on two cultivars of red-leaf 30 chicory (Cichorium intybus), rich in vitamins, minerals, and nutraceutical compounds. Their findings 31 revealed striking differences between cultivars and light treatments. The study showed that blue light 32 consistently enhanced the content of photosynthetic pigments and boosted the accumulation of 33 antioxidant polyphenols, such as quercetin derivatives, compared to red and white LEDs. In contrast, 34 red light not only reduced Photosystem II efficiency but also shifted the polyphenolic profile towards 35 a predominance of kaempferol derivatives. These results underscore that selecting specific light spectra 36 can effectively modulate the production of high-value nutraceutical metabolites in a species-specific manner. Importantly, this study emphasizes that plant metabolic plasticity depends not only on light 38 conditions but is also tightly linked to genetic background, highlighting the need for species-and 39 cultivar-specific protocols when manipulating light environments to enhance plant performance. 40 Complementing these experimental insights, the review by Wu et al. (2025) Although the direct warming effect at the leaf level was modest, their work revealed that NPQ-induced 57 thermal radiation from vegetation can represent a measurable component of Earth's energy balance. 58 Interestingly, they found that a small, yet non-negligible fraction (up to 0.55%) of the total thermal 59 radiation emitted from the Earth's surface originates from NPQ, highlighting it not only as a 60 photoprotective mechanism in plants but also as a minor, yet noteworthy, contributor to biosphere-61 atmosphere interactions. This study broadens our understanding of NPQ, framing it not merely as a 62 physiological defense mechanism but as a process with potential ecological and even atmospheric 63 implications, thereby demonstrating that photosynthetic regulation links micro-and macroscale 64 processes in unexpected ways. 65Finally, the opinion article by Aguirre-Böttger and Zolla (2024) adopts a broader evolutionary and 66 applied perspective, focusing on Solanaceae biodiversity as a key resource for sustainable food and 67 cosmetic production. Their contribution contextualizes photosynthetic efficiency and metabolic 68 diversity within the broader challenges of climate change and food security. Emphasizing the need for 69 sustainable food and cosmetic industries, the authors propose that wild relatives and underutilized 70 species display crucial genes for enhancing photosynthetic performance (e.g., related to PSII stability, 71RuBisCO kinetics, and electron transport) and the production of secondary metabolites such as 72 lycopene, under climate change-induced stress conditions. This perspective powerfully links the 73 conservation of genetic diversity with the practical goal of engineering crops that are both more 74 productive and resilient, identifying light-use efficiency as a key target. 75In conclusion, the contributions gathered in this Research Topic reflect the wide diversity of 76 approaches currently used to study light-driven metabolism, from detailed metabolic profiling and gene 77 expression analyses to theoretical climate models, biodiversity-based strategies, and applied 78 technologies. Despite their methodological diversity, these studies share a common thread: light 79 functions as an integrative signal linking molecular, physiological, and ecological scales within the 80 plant kingdom. 81As Topic Editors, we believe the path forward lies in strengthening the connections across these scales. 82Understanding how light quality and quantity shape plant metabolic networks requires not only the 83 study of individual pathways but also an assessment of their interconnections, from photons absorbed 84 by pigments to ecosystem-level productivity. Emerging technologies in photobiology, multi-omics, 85 and computational modeling are currently enabling a more holistic exploration of these relationships. 86 Furthermore, integrating this knowledge into dynamic models that predict plant behavior in fluctuating 87 natural environments will be crucial. Such a comprehensive understanding will shed new light on 88 strategies to improve crop productivity, enhance the nutritional value of plants, and better predict the 89 role of vegetation in a changing climate. 90