Research projects address plant productivity and range from whole-plant carbon partitioning to how growth patterns contribute to yield. We approach our questions with modern tools but always retain sight of the whole plant in our answers. Projects can be tailored for enthusiastic and motivated undergraduate, graduate, and postdoctoral scholars.

Phloem transport and carbon metabolism

Mature leaves are source tissues because photosynthesis produces a net surplus of sugar. These are transported to regions of growth and storage, termed sink tissues, through the phloem vascular network. A principal line of research is based on the hypothesis that manipulating the sugar content of the phloem can modulate transport patterns and target nutrients and biomass to desired organs (i.e., harvested organs for food, fiber or fuel). With support from the National Science Foundation, we are 1) studying how sucrose transporters contribute to carbon partitioning throughout the plant and if their manipulation can alter partitioning for enhanced productivity; 2) using metabolic engineering to modify sugars in the phloem to understand how the structure of the soluble carbohydrates contributes to translocation efficiency; and 3) manipulating genes encoding proteins that energize the phloem network, such as proton pumps and those contributing to glycolysis, to boost transport and growth in recipient tissues.

Long-distance signaling and plant architecture

Plant architecture and growth habit are fundamental agronomic traits and phloem-mobile signals are key regulators in source control of sink development. Genes in the CETS/PEBP gene family include the flowering factor FT (FLOWERING LOCUS T, encoding florigen) and the vegetative factor TFL1 (TERMINAL FLOWER 1). Stemming from our success in using phloem-mobile FT to induce flowering and facilitate breeding in cotton (Gossypium spp.), and with the support of the private foundation Cotton Incorporated and the USA / Israel Bi-National Agricultural Research and Development (BARD) fund, we are studying how each member of the cotton CETS gene family contributes to growth patterns. Cotton is the world's most important textile crop, the United States is the largest exporter, and Texas is the highest producing state. These projects contribute to UNT's "Signaling Mechanisms in Plants" research cluster to address basic plant development and have value to Texan, national, and international producers.

Carbon supply and metabolism in metabolic engineering

An emerging area of research is manipulating carbon supply for metabolic engineering. Dwindling fossil fuel supplies, mounting environmental concerns and anxiety over our dependence on foreign stocks emphasizes the importance of plants as versatile alternatives for fuels and chemical feedstocks. All of these bio-products have carbon backbones, and would benefit from a better understanding of how carbon supply influences final production levels. New projects ranging from addition of sugar to media, increasing photosynthesis, or elevating CO2 levels, to complex bio-engineering strategies, are being developed. These projects contribute to UNT's "Renewable Bioproducts" research Cluster.