Carotenoid biotechnology in plants for nutritionally improved foods

Abstract

Carotenoids participate in light harvesting and are essential for photoprotection in photosynthetic plant tissues. They also furnish non‐photosynthetic flowers and fruits with yellow to red colors to attract animals for pollination and dispersal of seeds. Although animals can not synthesize carotenoids de novo, carotenoid‐derived products such as retinoids (including vitamin A) are required as visual pigments and signaling molecules. Dietary carotenoids also provide health benefits based on their antioxidant properties. The main pathway for carotenoid biosynthesis in plants and microorganisms has been virtually elucidated in recent years, and some of the identified biosynthetic genes have been successfully used in metabolic engineering approaches to overproduce carotenoids of interest in plants. Alternative approaches that enhance the metabolic flux to carotenoids by upregulating the production of their isoprenoid precursors or interfere with light‐mediated regulation of carotenogenesis have been recently shown to result in increased carotenoid levels. Despite spectacular achievements in the metabolic engineering of plant carotenogenesis, much work is still ahead to better understand the regulation of carotenoid biosynthesis and accumulation in plant cells. New genetic and genomic approaches are now in progress to identify regulatory factors that might significantly contribute to improve the nutritional value of plant‐derived foods by increasing their carotenoid levels.

Direct regulation of phytoene synthase gene expression and carotenoid biosynthesis by phytochrome-interacting factors

“…Together, these results suggest that PIF1 specifically targets the PSY gene for the control of carotenoid biosynthesis during deetiolation. Consistently, the upregulation of PSY expression has been demonstrated to be sufficient by itself to increase carotenoid production in various plant systems, including deetiolating seedlings (5,9,36).…”

“…Along with their essential role in photosynthesis, carotenoids are also of significant economic interest as natural pigments and food additives. Their presence in the human diet provides health benefits as nontoxic precursors of vitamin A and antioxidants (9,36). In this context, manipulating the levels of PIF transcription factors by transgenic or marker-assisted breeding approaches might help improve carotenoid accumulation in plants for the production of varieties with enhanced agronomical, industrial, or nutritional value.…”

The contribution of transgenic plants to better health through improved nutrition: opportunities and constraints

“…Humans can produce retinal and retinoic acid if provided with a source of retinol or one of its esters, which are abundant in meat and dairy products. However, retinal can also be synthesized directly from b-carotene (also known as pro-vitamin A) which is produced mainly by plants and photosynthetic microbes, but also some non-photosynthesizing organisms (Botella-Pavía and Rodríguez-Concepción 2006). Vitamin A deficiency (VAD) is one of the most prevalent deficiency diseases in developing countries, affecting more than 4 million children each year, up to 500,000 of whom become partially or totally blind (Harrison 2005).…”

Genetic Enhancement of Grain Quality-Related Traits in Maize

“…Along with their essential role in photosynthesis, carotenoids are of significant economic interest as natural pigments and food additives (reviewed in Botella-Pavía & Rodríguez-Concepción, 2006). Their presence in the human diet provides health benefits as nontoxic precursors of vitamin A and antioxidants, including protection against cancer and other chronic diseases (review by Fraser & Bramley 2004).…”