What are Cartenoids?

Carotenoids are a class of natural fat-soluble pigments found principally in plants, algae, and photosynthetic bacteria, where they play a critical role in the photosynthetic process. They also occur in some non-photosynthetic bacteria, yeasts, and molds, where they may carry out a protective function against damage by light and oxygen. The most common carotenoids include lycopene and the vitamin A precursor, β-carotene. In plants, lutein is the most abundant carotenoid and it is believed to have a role in preventing age-related eye disease.

Animals are incapable of synthesizing carotenoids and must obtain them from their diet. In many crops used in human and animal diets, carotenoid levels are not adequate, and fortification of plants with these essential nutrients is needed.

What do carotenoids do?

In human beings, carotenoids can serve several important functions. The most widely studied and well-understood nutritional role for carotenoids is their provitamin A activity. Deficiency of vitamin A is a major cause of premature death in developing nations, particularly among children. Vitamin A, which has many vital systemic functions in humans, can be produced within the body from certain carotenoids, notably β-carotene. Dietary β-carotene is obtained from a number of fruits and vegetables, such as carrots, spinach, peaches, apricots, and sweet potatoes.

Carotenoids are known for their antioxidant activity, protecting cells and tissues from the damaging effects of free radicals and singlet oxygen. For example, lycopene from tomatoes is effective at quenching the destructive potential of singlet oxygen. Lutein and zeaxanthin, found in corn, spinach, and kale, are believed to function as protective antioxidants n the macular region of the human retina. Astaxanthin, found in salmon and shrimp, also has potent antioxidant properties. Other health benefits of carotenoids include enhancement of the immune system, protection from sunburn, and inhibition of the development of certain types of cancers.

Plants with increased levels of β-carotene can further be enhanced through genetic modification to convert the β-carotene to astaxanthin, a key ingredient for fish feed. Astaxanthin is a pigment added to the feed of cultured fish and shellfish to give the flesh its typical red/pink coloration. Currently, astaxanthin is obtained from sources such as crustaceans and chemical synthesis. Such sources yield only limited amounts of astaxanthin and its preparation is often costly, difficult and time-consuming. As a consequence, inclusion of astaxanthin from these sources accounts for up to 25% of the total feed cost, and 12% of total rearing costs for cultured fish. Although astaxanthin is not present in B. napus, the biochemical precursor of this pigment, namely β-carotene, is found naturally at low levels in the seeds of this plant.

This approach has been demonstrated using Brassica napus, however, other plants may also be modified using this method. The levels of β-carotene and total carotenoids in the seeds of Brassica napus were increased by 180- and 45-fold, respectively. In addition to increasing carotenoids in the seed, the regulation of ε-CYC can be used to alter the level of carotenoids in other plant tissues. Although the proof-of-concept of this technology was demonstrated using transgenic means, this modification can also be achieved using the non-transgenic TILLLING (Targeting Induced Local Lesions IN Genomes ) technology.

If interested in licensing this technology or for more information, please contact by July 31, 2009:

Alex Richman

Office of Intellectual Property & Commercialization

Telephone: (519) 457-1470 extension 269

Email: alex.richman@agr.gc.ca