Correction: Functional phytochemicals in tomatoes: biosynthesis, gene regulation, and human health implications

The tomato (Solanum lycopersicum) is one of the most popular and nutrient-dense vegetables in the world (Kumar et al., 2020). In addition to their many culinary uses, tomatoes are a great source of health promoting bioactive chemicals (Pinela et al., 2016). Flavonoids (like quercetin and kaempferol), phenolic acids (like chlorogenic acid), carotenoids (like lycopene and b-carotene), glycoalkaloids (like a-tomatine), and vitamins (like C and E) are some examples of these bioactive components useful substances (Szabo et al., 2025;Duma et al., 2018). These compounds exhibit antioxidant, anti-inflammatory, anticancer, and cardioprotective properties, making tomatoes a functional food with significant health benefits. The occurrence of these phytochemicals varies depending on genetic factors, environmental conditions, and postharvest handling (Tiwari and Cummins, 2013). Their biosynthesis is regulated by complex metabolic pathways involving key enzymes and transcription factors (Li et al., 2025). Understanding the genetic and molecular mechanisms behind their production can help in developing biofortified tomato varieties with enhanced nutritional value (Meng et al., 2022;Ofori et al., 2022). This article provides an in-depth exploration of the functional components in tomatoes, covering their; occurrence distribution in different tomato tissues and varieties, biosynthesis pathways key enzymatic steps in the production of carotenoids, flavonoids, and other metabolites, gene regulation transcriptional and posttranscriptional control of biosynthetic genes, and health benefits evidence-based roles in disease prevention and health promotion. By elucidating these aspects, we aim to highlight the importance of tomatoes as a dietary source of bioactive compounds and discuss potential strategies for enhancing their nutritional quality through breeding and biotechnology.Occurrence of functional components, tomatoes accumulate various phytochemicals in different tissues; such as carotenoids (lycopene, b-carotene, lutein) are predominantly found in the ripened fruit (Chaudhary et al., 2018;Wang et al., 2023b), with lycopene being the most abundant. Flavonoids (naringenin, rutin, quercetin) are concentrated in the peel and outer pericarp. Phenolic acids (chlorogenic acid, caffeic acid) are distributed throughout the fruit (Suleria et al., 2020). Glycoalkaloids (a-tomatine) are more abundant in green tomatoes and leaves (Kozukue et al., 2023). Factors such as cultivar type, ripening stage, light exposure, and agronomic practices influence their concentrations (Cervantes et al., 2019). Biosynthesis pathways of key phytochemicals; carotenoid biosynthesis derived from the methylerythritol phosphate (MEP) pathway (Saadullah et al., 2025), leading to geranylgeranyl pyrophosphate (GGPP) (Ezquerro, 2022). Phytoene synthase (PSY) catalysis the first committed step, forming phytoene (Zhou et al., 2022), the subsequent desaturation and isomerization reactions produce lycopene, which can be cyclized into b-carotene (Heymann et al., 2015), Figure 1 explain roles of transcription factor (SlBEL11) in biosynthesis of carotenoids. Flavonoid biosynthesis originates from the phenylpropanoid pathway, producing precursors like p-coumaroyl-CoA. Chalcone isomerase (CHI) and chalcone synthase (CHS) lead to naringenin chalcone, a precursor for various flavonoids (Tong et al., 2021;Saltzman, 2023;Waki et al., 2020). For glycoalkaloid biosynthesis derived from cholesterol, undergoing glycosylation to form a-tomatine, which decreases during fruit ripening. Gene regulation of biosynthetic pathways through transcription factors (TFs) such as RIN (Ripening Inhibitor), HY5 (Elongated Hypocotyl 5), and MYB regulators control carotenoid and flavonoid production (Liu et al., 2023;Xie et al., 2024). Epigenetic modifications (histone acetylation, DNA methylation) induce gene expression during ripening and the environmental signals (light, temperature) modulates biosynthetic gene activity via photoreceptors like phytochromes (Bianchetti et al., 2022;Li et al., 2022;Anwar et al., 2021).Health benefits of tomato bioactive compounds (lycopene, flavonoids, vitamin C, and a-tomatine) can reduces oxidative stress, lowers cardiovascular disease risk, and exhibit anticancer properties (especially prostate cancer) (Pinela et al., 2016;Friedman, 2013;Collins et al., 2022). Also, improve endothelial function and possess anti-inflammatory effects, enhances immune function and collagen synthesis, and shows antimicrobial and cholesterol lowering effects (Wozńiak et al., 2023). Tomatoes are a powerhouse of bioactive compounds with significant health promoting properties. While the targeted manipulation of gene regulation holds immense promise for enhancing functional phytochemicals in tomatoes, the approach is not without its significant current limitations. Scientifically, a primary concern remains the potential for off-target effects, where gene-editing tools like CRISPR-Cas9 could inadvertently alter unintended sections of the genome, potentially disrupting other vital metabolic pathways or plant functions, with consequences that are difficult to fully predict. Beyond the laboratory, consumer acceptance and complex regulatory landscapes present formidable hurdles. Widespread public skepticism, particularly regarding "GMO" technologies, and stringent, varying global regulations could severely limit the commercial viability and market access of these nutritionally enhanced tomatoes. Therefore, addressing these dual challenges of technical precision and societal trust is as crucial as the scientific breakthrough itself for the successful application of gene regulation in creating the next generation of functional foods. Advances in genomics and metabolic engineering offer opportunities to enhance these functional components, paving the way for improved dietary strategies and functional food development. Further research into gene regulation and bioavailability will maximize their therapeutic potential.Tomatoes (Solanum lycopersicum) have a wide range of bioactive chemicals with important nutritional and health benefits. Carotenoids (including lycopene and b-carotene), phenolic acids, flavonoids, vitamins C and E, and glycoalkaloids are responsible for the fruit's anti-inflammatory, anti-cancer, and antioxidant qualities (Figure 1). Genetic cultivar, ripening stage, and agronomic conditions all influence the composition and concentration of these bioactive compounds, which are highly variable. For instance, lycopene, the predominant carotenoid responsible for tomatoes' red colour, accumulates predominantly during the later stages of ripening, while certain flavonoids and chlorogenic acid levels may peak earlier. Environmental factors, including light exposure, temperature, soil quality, and water availability, further modulate phytochemical profiles, with organic cultivation and stress conditions (e.g., drought or salinity) often enhancing secondary metabolite production. Additionally, postharvest handling and processing methods (e.g., thermal treatment) can alter bioavailability and bioactivity. Understanding these dynamics is crucial for optimizing tomato production to maximize health benefits and for developing functional foods or nutraceuticals. The concentration of these phytochemicals varies significantly between green and ripening stages, influenced by biochemical and enzymatic changes during maturation as shown in Table 1. Lycopene, the predominant carotenoid in ripe tomatoes, increases dramatically during ripening due to the upregulation of lycopene biosynthesis pathways (Bramley, 2002;Zhu et al., 2022), while b-carotene levels may show a more gradual rise (Kozukue and Friedman, 2003;Kapoor et al., 2022). Phenolic acids and flavonoids, which are key antioxidants, often peak at intermediate ripening stages, as their synthesis is modulated by both developmental cues and environmental factors (Valero and Serrano, 2013). Vitamin C (ascorbic acid) tends to accumulate progressively with ripening (Fenech et al., 2019), whereas vitamin E (tocopherols) may exhibit a more stable or slightly declining trend (Galli and Azzi, 2010). Glycoalkaloids, such as a-tomatine, are typically higher in green tomatoes and decline as the fruit matures, meaning that glycoalkaloids play a role like a defense mechanism shift (Friedman, 2002;Faria-Silva et al., 2022). This dynamic profile of bioactive compounds highlights the importance of harvest timing in optimizing nutritional quality. Understanding these metabolic changes provides insights into breeding strategies and postharvest practices aimed at enhancing the health benefits of tomatoes for human consumption.Carotenoids are a class of bioactive compounds widely recognized for their antioxidant properties, with tomatoes (Solanum lycopersicum) being one of the richest dietary sources (Leoń-Garcıá et al., 2017). The major carotenoids in tomatoes include lycopene, b-carotene, lutein, and zeaxanthin, each contributing to the fruit's vibrant color and nutritional value (Ilahy et al., 2018). Among these, lycopene stands out as the most abundant, accounting for approximately 80-90% of total carotenoids, and is renowned for its potent antioxidant and antiinflammatory activities et al., and have lycopene to a of including cardiovascular certain and et al., 2023). The biosynthesis of carotenoids in tomatoes is influenced by and agronomic factors, such as cultivar type, ripening stage, light exposure, and postharvest handling and et al., 2024). in metabolic engineering and breeding strategies have aimed to enhance carotenoid particularly lycopene and b-carotene, to improve nutritional quality. 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