Combined Effects of Nutrients × Water × Light on Metabolite Composition in Tomato Fruits (Solanum Lycopersicum L.)

Abstract

Tomato cultivation in the greenhouse can be facilitated by supplemental light. We compared the combined effects of nutrients, water, and supplemental light (red) on tomato fruit quality. To do this, three different nutrient conditions were tested, i.e., (1) low N, (2) standard N, and (3) high N. Water was supplied either at −30 kPa (sufficient) or −80 kPa (limited) of soil water potential. Supplemental red LED light was turned either on or off. The metabolites from tomato fruits were profiled using non-targeted mass spectrometry (MS)-based metabolomic approaches. The lycopene content was highest in the condition of high N and limited water in the absence of supplemental light. In the absence of red lighting, the lycopene contents were greatly affected by nutrient and water conditions. Under the red lighting, the nutrient and water conditions did not play an important role in enhancing lycopene content. Lower N resulted in low amino acids. Low N was also likely to enhance some soluble carbohydrates. Interestingly, the combination of low N and red light led to a significant increase in sucrose, maltose, and flavonoids. In high N soil, red light increased a majority of amino acids, including aspartic acid and GABA, and sugars. However, it decreased most of the secondary metabolites such as phenylpropanoids, polyamines, and alkaloids. The water supply effect was minor. We demonstrated that different nutrient conditions of soil resulted in a difference in metabolic composition in tomato fruits and the effect of red light was variable depending on nutrient conditions.

Response of Tomato Fruit Quality Depends on Period of LED Supplementary Light

“…Both the leaves and fruits of tomato contain photoreceptors, including phytochrome and cryptochrome (17,18), and appropriate illumination can promote the absorption of light and enhance the photosynthetic capacity of tomato (19). Moreover, light can contribute to promoting the absorption and transport of water and nutrients (20), thereby influencing metabolic processes and metabolite production (21). Lightemitting diodes (LEDs) are an efficient environmentally friendly source of artificial light, the supplementary illumination provided by which can promote the growth and development of tomatoes and other vegetables (22,23), and the findings of recent studies have revealed that such supplementary light can play an important role in improving tomato fruit quality.…”

Effects of limited water supply on metabolite composition in tomato fruits (Solanum lycopersicum L.) in two soils with different nutrient conditions

“…Sample preparation and extraction steps were adopted for our previous research ( Kim et al, 2021 ). Cultivated tomato fruits under varied nutrient and water conditions were washed with distilled water and wiped before being stored at a deep freezer (−80°C).…”

“…One microliter of each sample was injected at split mode (ratio 1: 20). The GC-TOF-MS instrument, analytical protocol, and parameter setting for analysis were adopted for our previous research ( Kim et al, 2021 ).…”

“…For secondary metabolites, the re-dissolved samples were analyzed using UHPLC-LTQ-Orbitrap-MS equipped with Vanquish binary pump H system (Thermo Fisher Scientific, Waltham, MA, United States) coupled with an auto-sampler and column compartment. The analytical methods and operation parameters were followed by our previous study ( Kim et al, 2021 ). All samples were run in a randomized manner to reduce bias and systematic errors.…”

“…Primary and secondary metabolites of tomato fruits were investigated using a non-targeted metabolomics. The metabolomics is a comprehensive approach to evaluate different metabolomes under a specific set of conditions ( Son et al, 2016 ), and we have applied it for various crops in response to varying environmental factors including light and mineral nutrient supply ( Kwon et al, 2019 ; Gil et al, 2020 ; Kim et al, 2020 , 2021 ; Suh et al, 2020 ).…”