Page Banner

United States Department of Agriculture

Agricultural Research Service

Li Li
headline bar
Selected Publications Personal Bio Curriculum Vitae URLs for Li

pict of li li

Li Li
Plant Molecular Biologist
Phone: (607)255-5708
Fax: (607)255-1138
E-mail: Li.Li@ars.usda.gov

Research

 

Our research goal is to improve the nutritional quality and health-promoting properties of food crops. Currently, we focus primarily on gene discovery and understanding of the mechanisms underlying phytonutrient and micronutrient metabolisms in plants, as well as on plant biotechnology to metabolically engineer health beneficial compounds in crops.

 

Carotenoid Biosynthesis and Genetic Engineering in Plants

  

Carotenoids are indispensable to plants and play a critical role in human nutrition and health. Carotenoids are synthesized and accumulated in high levels in chromoplasts, which serve as a metabolic sink. Using a high- b-carotene Or (Orange) gene mutation in cauliflower (Brassica oleraceaL.) as a model, we have elucidated a regulatory mechanism of carotenogenesis by inducing the differentiation of non-colored plastids into chromoplasts. We are studying how the Or gene mediates chromoplast formation. Comparative genomic and proteomic approaches are used to identify proteins affected by Orfor elucidation of the metabolic processes associated with carotenogenesis.

 

We are also investigating the metabolic processes associated with high levels of carotenoid accumulation in other food plants via molecular, biochemical, genomic, and proteomic approaches. The research should provide new insights into the regulatory control of carotenogenesis in plants.

 

In addition, plant biotechnology approach is used to introduce carotenoid biosynthetic and other associated genes into crops for better understanding of the gene functions and for enhancing the nutritional value of food crops.

  

Regulation of Flavonoid Biosynthesis

 

Flavonoids fulfill important biological functions in protecting plants against various biotic and abiotic stresses, and serve as valuable diet antioxidants in reducing the risk of a number of human diseases. We are using mutants of Brassica oleraceavegetable crops as models to gain a better understanding of the regulatory control of flavonoid metabolism in plants. Current we focus on identification and functional characterization of the key genes controlling flavonoids biosynthesis. Information obtained should be valuable for altering plant s in a controlled manner to modify the antioxidant content and/or composition of food crops.

 

Selenium Biofortification and Selenium Metabolismin Plant

 

Selenium is an essential micronutrient for humans and has important health benefits including as a cancer preventative agent. We are working on selenium biofortification in vegetable crops. We are investigating the potential important genes controlling selenium metabolism via genomic approach. Particularly, we are interested in isolating metabolic and regulatory genes promoting the formation of bioactive forms (with anticarcinogenic properties) of selenium and reducing the formation of volatile selenium in Brassica species. The goal of this research is to develop food plants with the ability to accumulate high level of bioactive forms of selenium.


Last Modified: 4/1/2010