Location: Wheat, Sorghum and Forage Research
Project Number: 3042-21220-033-000-D
Project Type: In-House Appropriated
Start Date: Feb 6, 2018
End Date: Feb 5, 2023
Objective 1: Identify and manipulate the genetic and biochemical mechanisms controlling lignin deposition to develop improved sorghum germplasm for bioenergy and forage uses. Subobjective 1A: Characterize the effects six recently identified brown midrib mutants (bmr) on phenylpropanoid metabolism and lignin deposition. Subobjective 1B: Evaluate ways to increase lignin deposition and alter phenolic composition of biomass through overexpression of monolignol genes. Objective 2: Identify and manipulate the genetic and biochemical mechanisms controlling starch and phosphorus composition of grain to develop novel sorghum traits for food, biofuel and livestock production. Subobjective 2A: Identify and characterize mutants that alter phosphorus composition and reduce phytate in grain. Subobjective 2B: Develop germplasm with altered starch composition and content in grain. Objective 3: Identify resistance to fungal pathogens in lignin modified sorghum germplasm for development of stalk rot-resistant grain, bioenergy, and forage sorghums. Subobjective 3A: Determine the responses of sorghum lines with six recently identified bmr mutants to stalk pathogens. Subobjective 3B: Assess impact of the stalk pathogen Fusarium thapsinum on sorghum with altered the monolignol synthesis. Subobjective 3C: Determine the response of sorghum stalk moisture phenotypes on stalk rot pathogens. Subobjective 3D: Determine whether beneficial microorganisms increase protection of bmr mutants against root and stalk pathogens. Objective 4: Identify resistance interactions between sorghum grain with novel composition and fungal pathogens for food, fuel, and feed uses. Subobjective 4A: Determine whether pericarp pigments provide protection against grain pathogens. Subobjective 4B: Determine whether grain tannins prevent fungal infection.
Sorghum (Sorghum bicolor) is a climate resilient crop, which is capable of providing grain and forage (biomass) to both the existing agricultural markets and the emerging bioenergy markets in the United States. To compete in these markets, compositional improvements to both sorghum grain and forage are needed and an understanding how these changes affect the fungal pathogens of sorghum. The objectives of this project will focus on the genetic, biochemical, and physiological mechanisms affecting the composition of sorghum biomass and grain. Efforts will result in sorghum with altered lignin content and/or composition of biomass, and increased starch content and reduced phytate content of grain for improved bioenergy conversion, livestock utilization and human nutrition. The impacts of fungal pathogens on sorghum with compositionally modified biomass and grain will be determined. Sorghum germplasm with desirable traits enhancing sorghum biomass and grain utilization will be developed, fully characterized, released and deposited into USDA–ARS National Plant Germplasm System (NPGS) for use by public and private sector plant breeders for developing improved hybrids and cultivars. The project consists of three integrated components: germplasm development, molecular biology, and plant pathology. Molecular and conventional methodologies will be utilized, and the project scale will range from gene-level to field-level. The project also has extensive formal and informal collaborations enhancing our ability to conduct this research. Anticipated products include improved sorghum germplasm for the sorghum seed industry with value-added traits and biotic stress tolerance, and tools to assess these biological pathways and fungal pathogen responses of sorghum.