INVESTIGATORS: Deanna Funnell-Harris (PI), Scott E. Sattler, Erin D. Scully
INSTITUTIONS: USDA ARS Grain, Forage and Bioenergy Research Unit (GFBRU), Lincoln, NE; USDA ARS Stored Product Insect and Engineering Research Unit (SPIERU), Manhattan, KS
PROJECT SUMMARY: Sorghum is an attractive bioenergy crop with high yield potentials and significant tolerance to drought and heat. However, sorghum is prone to stalk rots, which can significantly limit sorghum biomass production through yield reductions and lodging. Stalk rot-causing fungi normally grow endophytically within sorghum plants. When sorghum plants experience water stress, changes in host metabolism often triggers a developmental switch causing the fungi to become pathogenic. The underlying plant molecular circuits that can limit or exacerbate fungal transition from endophytic to pathogenic growth are not known and are the focus of this proposal.
The specific objectives of this proposal are: 1) to determine pathogenic and endophytic growth of stalk pathogens in sorghum lines under water deficit conditions; 2) to identify host metabolites and metabolic pathways involved in resistance or tolerance to fungal stalk rot pathogens under water deficit conditions in lignin modified, nonsenescent and stalk rot resistant/tolerant lines; 3) to identify host genes from the phenylpropanoid and defense-related pathways with altered expression levels during pathogenic or endophytic growth of fungal stalk pathogens under water deficit conditions; and 4) to identify genes, gene networks, and metabolic pathways whose expression is altered in stalk rot tolerant sorghum lines under water sufficient versus deficit conditions.
Our aim is to discover host molecular pathways that enhance endophytic growth of stalk fungi and inhibit the developmental switch to pathogenic growth that frequently occurs under periods of prolonged abiotic stress. From this valuable research, we will identify biomolecular markers for resistance that will significantly enhance efforts to develop superior bioenergy sorghum with resistance to increasing disease and environmental stresses.
Name: Funnell-Harris, Deanna