Location: Wheat, Sorghum and Forage ResearchTitle: Modifying cell wall phenylpropanoids of small grains for increased usability and disease and drought resistance
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 9/3/2020
Publication Date: 9/3/2020
Citation: Funnell-Harris, D.L., Sattler, S.E., Khasin, M., Wegulo, S. 2020. Modifying cell wall phenylpropanoids of small grains for increased usability and disease and drought resistance.[Abstract]. Complex Biosystems Seminar Series, University of Nebraska, Lincoln, Sept. 3, 2020.
Technical Abstract: Phenylpropanoid metabolites, including the lignin polymer, have long been implicated in plant defense as induced or extant physical barriers within plant cell walls to limit pathogen ingress and as antimicrobial or signaling molecules directly or indirectly inhibiting pathogen progression. In sorghum, modification of lignin has been used to increase biomass usability for forages and bioenergy. Our research group has extensively examined the effects of brown midrib (bmr) mutants that primarily effect expression of genes in the monolignol biosynthesis pathway, on cell wall phenylpropanoid content and composition. Using bmr mutants, we have established that perturbations in monolignol biosynthesis that reduce lignin content in the biomass, can actually increase resistance to some stalk and grain pathogens, counter to traditional concepts of the role of lignin in defense. We have also constitutively expressed sorghum monolignol biosynthesis genes in both sorghum and wheat, further demonstrating effects of changes in cell wall phenylpropanoids on pathogen responses to stalk pathogens in sorghum and to the devastating Fusarium head blight pathogen in wheat. In this way, we have been able to elucidate possible roles that soluble and cell wall-bound phenolics may play in plant defense against specific fungal pathogens. Global gene expression and phenylpropanoid metabolite analyses indicated the expansive effects of sorghum bmr mutations in response to pathogen attack and drought.