Developing carotenoids-enhanced tomato fruit with multi-transgene stacking strategies.

Area of Science:

• Plant Biotechnology
• Nutritional Genomics
• Agricultural Science

Background:

• Carotenoids are vital pigments in fruits, offering health benefits and influencing quality.
• Tomatoes are a key dietary source of carotenoids, making carotenoid-biofortified varieties highly desirable.
• Carotenoid biosynthesis is a complex pathway regulated by multiple genes and enzymes.

Purpose of the Study:

• To develop carotenoid-biofortified tomatoes using a multi-gene stacking system.
• To investigate the effects of overexpressing specific carotenoid metabolic genes on carotenoid accumulation.
• To assess the impact on nutritional content and antioxidant capacity.

Main Methods:

• Assembled binary constructs with four endogenous carotenoid metabolic genes (SlORHis, SlDXS, SlPSY, SlBHY).
• Utilized a high-efficiency multi-transgene stacking system and fruit-specific promoters.
• Generated transgenic tomato lines overexpressing single or multiple genes.

Main Results:

• Transgenic lines showed varying degrees of carotenoid enrichment.
• Overexpression of SlORHis alone was as effective as overexpressing SlDXS, SlPSY, and SlORHis simultaneously.
• Zeaxanthin and violaxanthin were detected in lines containing SlBHY; sugar content and antioxidant capacity increased.

Conclusions:

• A multi-gene engineering strategy is effective for developing nutrient-biofortified tomatoes.
• SlORHis is a key target for enhancing carotenoid accumulation.
• This system allows for the creation of tomatoes with tailored carotenoid profiles for improved nutrition.