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ARS Home » Pacific West Area » Maricopa, Arizona » U.S. Arid Land Agricultural Research Center » Plant Physiology and Genetics Research » Research » Research Project #424563

Research Project: Molecular Genetic Analysis of Abiotic Stress Tolerance and Oil Production Pathways in Cotton, Bioenergy and Other Industrial Crops

Location: Plant Physiology and Genetics Research

Project Number: 2020-21000-012-000-D
Project Type: In-House Appropriated

Start Date: Mar 26, 2013
End Date: Mar 25, 2018

Objective 1: Discover and characterize biochemical and molecular factors that limit photosynthetic capacity of plants at elevated temperatures and under water-limited conditions that can be exploited to develop molecular targets for generating stress-tolerant crops. Objective 2: Identify genes and biochemical pathways involved in production of the protective, waxy layer of plant surfaces, and determine their relationships with tolerance to abiotic stress. Subobjective 2.1: Develop high-throughput screening strategies to identify new genes and alleles controlling production of plant cuticle lipids related to drought stress tolerance. Subobjective 2.2: Elucidate the cellular and drought-stress-related physiological functions of newly identified cuticle genes. Objective 3: Identify genes and/or molecular processes that regulate seed oil concentration and composition in oilseed crops, including under abiotic stress conditions, and determine molecular mechanisms that regulate oil production pathways in plant vegetative biomass. Subobjective 3.1: Identify and characterize genes involved in determining oil content and composition in B. napus, including under heat and drought conditions. Subobjective 3.2: Elucidate the role of the CGI-58 gene in regulating triacylglycerol content and lipid signaling pathways in plant leaves and seeds.

The research program includes a variety of experimental approaches including statistical genetics and genomics as well as molecular and biochemical studies of model plants such as Arabidopsis and camelina, as well as field-based studies of cotton and Brassica napus. To uncover natural mechanisms for heat and drought tolerance in cotton, we will examine the genetic variability for these traits using a high-throughput phenotyping platform to determine canopy temperature in combination with measurements of lint yield and carbon isotope discrimination. We will further develop a high-throughput assay for Rubisco activity as a tool in our high-throughput phenotyping platform to uncover natural mechanisms that might improve or stabilize Rubisco activase in response to heat stress. To identify genes associated with cuticle and oil production, we will use both statistical genetics and candidate gene-based approaches to identify highly active allese in a diverse B. napus germplasm that are associated with altered cuticle or oil properties. We will also employ mutagenic screens of Arabidopsis to isolate a unique class of putative cuticle stress responsive genes. The molecular and biochemical function of oil and cuticle related genes and their encoded enzymes will be examined using a variety of model systems including Arabidopsis, yeast cells, and bacteria. Finally, production of oil in plant leaves will be studied by examining the function of a gene called CGI-58 gene, which plays a key role in regulating lipid metabolism, oil content, and stress-response signaling in plant leaves. The end-goal is to develop the knowledge base and molecular tools required for dramatically increasing the oil (energy) content of a rapidly growing biomass crop such as switchgrass or Miscanthus.