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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Sustainable Agricultural Systems Laboratory » Research » Publications at this Location » Publication #296692

Title: Genetic regulation of health beneficial phytonutrients in fresh produce

Author
item HANDA, AVTAR - Purdue University
item ANWAR, RAHEEL - Purdue University
item Mattoo, Autar

Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 10/5/2013
Publication Date: 1/1/2014
Citation: Handa, A.K., Anwar, R., Mattoo, A.K. 2014. Genetic regulation of health beneficial phytonutrients in fresh produce. International Symposium on Human Health Effects of Fruits and Vegetables. 29-35.

Interpretive Summary: A number of nutrients present in fruits and vegetables, called phytonutrients, have been found to be bioactive, with a potential to prevent diseases in humans and animals. However, phytonutrient levels in plants are considered to be below the threshold levels needed for optimal benefits. Low levels of health promoting phytonutrients are due to tight genetic and developmental controls of their metabolic pathways during plant growth and development. In many instances, information about biosynthetic pathways for phytonutrients is incomplete, and germplasm with higher phytonutrient content is not easily available. Conventional breeding has not been successful in boosting the levels of some phytonutrients. Modern tools of metabolomics, which quantifies a large number of phytochemicals, together with the technology for engineering metabolic pathways using genetic engineering are increasingly being used to elevate the levels of biologically active phytochemicals to boost nutritional content of crops. USDA scientist teamed with collaborators at Purdue University to bring out a condensed version of their research findings utilizing transgenic plants engineered to express a key rate-limiting gene in the biosynthesis of polyamines. The high-polyamine expression causes activation of a wide array of genes regulating transcription, translation, signal transduction, chaperone activity, stress proteins, amino acid biosynthesis, ethylene biosynthesis and action, isoprenoid pathway, and flavonoid biosynthesis. The use of these biogenic signaling molecules is expected to provide an alternative strategy to maximize the content of phytonutrients in fruits and vegetables. This information is of use to nutritionists, plant biologists and interdisciplinary scientists.

Technical Abstract: Compelling evidence in literature supports the hypothesis that dietary phytonutrients, especially antioxidants, maintain human health and prevent chronic diseases such as cancer, diabetes, osteoporosis, cardiovascular and age-related disorders, including dementia. Fresh fruits and vegetables are dietary sources of beneficial phytonutrients, and therefore, their consumption has increased in recent decades. However, health promoting phytonutrients in currently-used germplasm of fruits and vegetables are not at sufficient levels to achieve the threshold levels that could be beneficial. The tight, endogenous regulation of metabolic pathways for the biosynthesis of phytonutrients makes it difficult to increase the levels of phytonutrients to desired levels by conventional breeding in current fruit and vegetable germplasm. Molecular breeding and genetic engineering of crops have begun to provide novel methods to enhance levels of the desirable phytonutrients by overcoming this regulation by introducing genes that are rate limiting for the production of the desirable phytonutrients. Our approach includes increasing the levels of various phytonutrients in fruits by identifying molecular regulators of biochemical pathways, and genetically engineering them to enhance metabolic activity of cells to increase the levels of desirable phytonutrients. Here, we summarize various tools available to enhance levels of phytonutrients in fresh produce. A separate approach for modifying levels of phytonutrients is presented which involves engineering higher levels of biogenic amines that are molecular regulators of several cellular biochemical pathways. Along with engineering the levels of health-promoting carotenoid lycopene, we have demonstrated that spermidine and spermine also extend longevity of a ripe fruit and delay whole plant senescence. Higher endogenous levels of biogenic polyamines also activate a wide array of genes regulating transcription, translation, signal transduction, chaperone activity, stress proteins, amino acid biosynthesis, ethylene biosynthesis and action, isoprenoid pathway, and flavonoid biosynthesis.