Grantee Research Project Results

Carotenoid Levels in Crops: Implications for Stress Tolerance and Nutrition

EPA Grant Number: F5F61397
Title: Carotenoid Levels in Crops: Implications for Stress Tolerance and Nutrition
Investigators: Pirone, Cary
Institution: Florida International University
EPA Project Officer: Hahn, Intaek
Project Period: September 5, 2005 through April 8, 2005
Project Amount: $97,463
RFA: GRO Fellowships for Graduate Environmental Study (2005) RFA Text |  Recipients Lists
Research Category: Academic Fellowships

Objective:

Carotenoids influence many plant processes including the protection of photosynthetic components against oxidative damage and the dissipation of excess absorbed energy. These functions moderate the effects of varying temperatures and ultraviolet (UV) light intensity, thus maintaining plant productivity in times of environmental stress. In the human body, carotenoids relieve oxidative stress and thereby promote human health. Enhancing the carotenoid content of food plants is therefore desirable from both an agricultural as well as a nutritional perspective. Evidence suggests wild plant species may serve as novel sources of carotenoid rich germplasm. However, a paucity of information regarding carotenoid variation indicates the need for further study of both wild and cultivated crop genotypes.

The primary objectives of my research are:

1. To quantify the carotenoids lycopene, β-carotene, lutein, and zeaxanthin in several tomato cultivars and species,
2. and to measure total antioxidant activity and determine the relationship between carotenoid composition and total antioxidant content.

Approach:

One of the most economically important global vegetable crops, tomato, Solanum esculentum, will be used as a model. Sample populations, including six commercially important cultivars, six cultivars important for organic agriculture, and seven wild species, will be raised from seed in the FIU greenhouse and harvested for analysis. The lipophilic fraction of tomato fruits will be analyzed for carotenoid content using high performance liquid chromatography (HPLC). Total antioxidant activity of whole tomato extract will be measured using two methods; anti-radical power assay (ARP), and inhibition of lipid peroxidation assay (ILP).

Expected Results:

Total carotenoid content of plants is expected to be lowest among commercial species and highest in wild species. Individual quantities of isolated carotenoids will most likely fluctuate independently of each other and vary with species and cultivar. Carotenoid antioxidant activity will vary depending on the ratio of individual carotenoid constituents; plants with high levels of lycopene and beta-carotene will likely demonstrate greater antioxidant activity than those containing high levels of lutein or zeaxanthin.

Supplemental Keywords:

environmental stress, carotenoids, antioxidant, agriculture, tomatoes, human health, intraspecific chemical variation ,, RFA, Ecosystem Protection/Environmental Exposure & Risk, Monitoring/Modeling, environmental monitoring, antioxidants, stressors, UV effects, carotenoid, lycopene, agrobiodiversity, environmental stress, nutrient monitoring , human health