Location: Wheat, Sorghum and Forage ResearchTitle: The impacts of lignin modifications on fungal pathogen and insect interactions in sorghum
|CLEMENTE, THOMAS - University Of Nebraska|
Submitted to: Association for the Advancement of Industrial Crops Conference
Publication Type: Abstract Only
Publication Acceptance Date: 10/16/2013
Publication Date: 10/16/2013
Publication URL: http://www.aaic.org/2013%20AAIC%20Abstract%20book.pdf
Citation: Sattler, S.E., Clemente, T.E., Funnell-Harris, D.L., Dowd, P.F., Prom, L.K., Huang, Y. 2013. The impacts of lignin modifications on fungal pathogen and insect interactions in sorghum. Association for the Advancement of Industrial Crops Conference. Crop Development, Production and Protection. Poster Session Page 133.
Technical Abstract: Sorghum (Sorghum bicolor (L.) Moench) is currently being developed as a dedicated bioenergy feedstock. Modifying lignin content and composition are major targets for bioenergy feedstock improvement. However, lignin has long been implicated as playing a critical role in plant defense responses against pathogens and insect pests. Therefore, it is critical to determine whether changes to lignin synthesis affect susceptibility to pathogens and pests prior to deployment in the field. Our goals are to improve sorghum biomass for both biochemical and thermal bioenergy conversion by developing experimental lines that have altered lignin content and composition beyond normal levels, and to understand how lignin modifications will affect biotic interactions. To reduce lignin content and alter lignin composition, brown midrib (bmr) mutants, generated through chemical mutagenesis, are being utilized. To increase lignin content for thermal bioenergy conversion, a series of transgenic lines overexpressing phenylpropanoid biosynthetic genes and a pathway regulatory gene are being developed. We are examining whether the lignin-modified lines have altered susceptibility to key sorghum insect pests (phloem feeding greenbugs, Schizaphis graminum; chewing insects fall armyworms, Spodoptera frugiperda and corn earworms, Helicoverpa zea) and fungal pathogens that cause foliar (anthracnose; Colletotrichum sublineolum) and stalk (stalk rot; Fusarium thapsinum and charcoal rot; Macrophomina phaseolina) diseases. Our findings indicated bmr6 and bmr12 plants do not have increased susceptibility to the pests and pathogens tested, and in some instances showed increased resistance. Likewise, the transgenic lines overexpressing elements of the phenylpropanoid biosynthetic pathway tested did not show increased susceptibility to the pests and pathogens tested. In some instances, specific transgenic lines appeared to be more resistant to a pathogen or pest than the corresponding wild-type. Overall, our data suggests that altering the lignin content and composition to improve bioenergy feedstocks will not inevitably result in increased susceptibility to pathogens and insect pests.