MOLECULAR APPROACHES TO ENHANCE PLANT NUTRIENT CONTENT, SHELF-LIFE AND STRESS TOLERANCE
Title: Potential for engineering horticultural crops with high-antioxidant capacity
Submitted to: CAB Reviews: Perspectives in Agriculture, Veterinary Science, Nutrition and Natural Resources
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 21, 2009
Publication Date: December 1, 2009
Citation: Shukla, V., Mattoo, A.K. 2009. Potential for engineering horticultural crops with high-antioxidant capacity. CAB Reviews: Perspectives in Agriculture, Veterinary Science, Nutrition and Natural Resources. 4(066):1-22.
Interpretive Summary: Nutritional and antioxidative capacity of fruits has generated interest among plant scientists and human health researchers alike since nutrition-enriched food has the potential as a preventive strategy to decrease incidence of diet-related diseases. A nutritive diet can be beneficial via interactions of several antioxidant components present in food, although the nature of these interactions is still a matter of conjecture. Genetic engineering has been applied to enhance the concentration of useful nutrients in fruit crops. Some of these fruits have been tested in animal systems and found to provide protection against diet-related diseases, and improved life span. This is an invited review in which we have attempted to provide a common theme on the nutritional and antioxidant capacity of fruits, nutritive antioxidants, the potential of engineering enhanced nutritional quality in fruits, and the contribution of nutritional and quality diet in enhancing quality of life by reducing disease. This review will be valuable to plant biologists, geneticists, nutritionists and academicians.
Cellular oxidation index has emerged as an important determinant in defining the fate of a living cell and its susceptibility to disease. Oxidative stress targets include oxidation of DNA, protein and lipids, causing cellular oncogenesis, chronic diseases and premature senescence. That dietary intervention via nutrition-enriched food may significantly decrease incidence of diet-related diseases has catalyzed scientific efforts to understand this relationship which is fundamental to developing future strategies for stemming disease. Multiple and synergistic interactions among nutrients influence antiproliferative activity of a fruit compared to an isolated antioxidant. Nutritional molecules including vitamins (B, C, E and beta-carotene), folates, lycopene, flavonoids, isothyocyanates, glucosinolates, polyphenols, glutathione and minerals contribute to the antioxidative capacity of vegetables, fruits, nuts and various herbs. However, the levels of antioxidants present in fruits are low and significantly influenced by genotype/cultivar, growth condition and developmental stage. Genetic engineering has come to the rescue as a refined tool to increase the antioxidant and nutrient capacity of fruits to the levels favorable for not only for a highly nutritional diet but also to enable in-depth studies on the relationships between diet, genetics and metabolism. Together with modern biotechnology, deciphering transcriptome-proteome-metabolome of the new transgenics should provide new knowledge to ease the concerns of the society and open the market for genetically engineered horticulture crops, as is seen by higher sales of Hawaii-grown transgenic papaya in the United States. Also, this knowledge will help develop precise strategies for redesigning metabolic pathways so that desired levels of a particular phytonutrient (antioxidant) in a fruit or other crops are achieved.