Biochemical and Functional Analysis of Carotenoid Biosynthetic Enzyme Complexes in Tomato Fruits
Abstract
Carotenoids are essential pigments in plants, playing critical roles in photosynthesis, photoprotection, and human nutrition. While the biosynthetic pathway of carotenoids is well characterized, the spatial organization and dynamic assembly of biosynthetic enzyme complexes within chromoplasts remain poorly understood. This study investigates the structural and functional organization of carotenoid biosynthetic enzymes in tomato (Solanum lycopersicum) fruits, focusing on the impact of enzyme complex compositions on metabolic flux and carotenoid composition. To explore these dynamics, we employed CRISPR-Cas9 genome editing to generate a Zeta-carotene isomerase (Z-ISO) knockout mutant, which will be analyzed alongside a diverse set of genetic materials in the Ailsa Craig (AC) background, including natural mutants (r, tangerine, Beta, and Delta). Intact chromoplasts were isolated and fractionated into plastoglobuli, membrane, and stroma compartments using nycodenz density-gradient ultracentrifugation. The sub-organellar localization of key biosynthetic enzymes was determined via Western blot analysis. To identify the native composition of these enzyme complexes, mass spectrometry was performed on the isolated fractions. Furthermore, high-performance liquid chromatography (HPLC) was used to quantify carotenoid accumulation and analyze pathway flux, providing insights into the metabolic channeling mechanisms that drive specific carotenoid outcomes. Our results to date suggest that compartmentalization within the chromoplast is critical for regulating carotenoid composition and the formation of globular or crystalline storage structures. This research provides fundamental insights into plastidial metabolic regulation and offers a framework for metabolic engineering and crop biofortification strategies aimed at improving nutritional quality and addressing global vitamin A deficiency.
Start Time
15-4-2026 10:00 AM
End Time
15-4-2026 11:00 AM
Room Number
311
Presentation Type
Oral Presentation
Presentation Subtype
Grad/Comp Orals
Presentation Category
Science, Technology, and Engineering
Student Type
Graduate
Faculty Mentor
Tianhu Sun
Biochemical and Functional Analysis of Carotenoid Biosynthetic Enzyme Complexes in Tomato Fruits
311
Carotenoids are essential pigments in plants, playing critical roles in photosynthesis, photoprotection, and human nutrition. While the biosynthetic pathway of carotenoids is well characterized, the spatial organization and dynamic assembly of biosynthetic enzyme complexes within chromoplasts remain poorly understood. This study investigates the structural and functional organization of carotenoid biosynthetic enzymes in tomato (Solanum lycopersicum) fruits, focusing on the impact of enzyme complex compositions on metabolic flux and carotenoid composition. To explore these dynamics, we employed CRISPR-Cas9 genome editing to generate a Zeta-carotene isomerase (Z-ISO) knockout mutant, which will be analyzed alongside a diverse set of genetic materials in the Ailsa Craig (AC) background, including natural mutants (r, tangerine, Beta, and Delta). Intact chromoplasts were isolated and fractionated into plastoglobuli, membrane, and stroma compartments using nycodenz density-gradient ultracentrifugation. The sub-organellar localization of key biosynthetic enzymes was determined via Western blot analysis. To identify the native composition of these enzyme complexes, mass spectrometry was performed on the isolated fractions. Furthermore, high-performance liquid chromatography (HPLC) was used to quantify carotenoid accumulation and analyze pathway flux, providing insights into the metabolic channeling mechanisms that drive specific carotenoid outcomes. Our results to date suggest that compartmentalization within the chromoplast is critical for regulating carotenoid composition and the formation of globular or crystalline storage structures. This research provides fundamental insights into plastidial metabolic regulation and offers a framework for metabolic engineering and crop biofortification strategies aimed at improving nutritional quality and addressing global vitamin A deficiency.
