Location: Grain, Forage & Bioenergy Research
Title: Response of fusarium thapsinum to sorghum brown midrib lines and to phenolic metabolites Authors
Submitted to: APS Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: May 9, 2014
Publication Date: August 9, 2014
Citation: Funnell-Harris, D.L., Sattler, S.E. 2014. Response of fusarium thapsinum to sorghum brown midrib lines and to phenolic metabolites. APS Annual Meeting. http://www.apsnet.org/meetings/Documents/2014_meeting_abstracts/aps2014abO71.htm. Technical Abstract: Sorghum lines were bred for reduced lignin for cellulosic bioenergy uses, through the incorporation of brown midrib (bmr) bmr6 and/or 12 into two genetic backgrounds, either as single or double mutant lines. When these lines were assessed for resistance to F. thapsinum stalk rot, a cause of lodging, they were as resistant to F. thapsinum as near-isogenic wild-type lines. Peduncles of newly identified bmr lines from an ethyl-methanesulfonate-mutagenized population, inoculated with F. thapsinum, were as resistant as the wild-type line, BTx623. One bmr line (1107) had significantly smaller mean lesion lengths than BTx623, suggesting a mutation is associated with reduced susceptibility. Growing F. thapsinum on medium with ferulic, vanillic, sinapic, syringic and caffeic acids, phenolic compounds derived from the lignin pathway and elevated in different bmr lines, indicated that F. thapsinum was tolerant to these compounds. Eight sorghum fungi were also tested for effects on growth by the presence of these compounds and ferulic acid inhibited these fungi. Most of the phenolics inhibited F. verticillioides and F. proliferatum. Accumulation of phenolic metabolites in bmr plants may inhibit growth of some sorghum pathogens, while other factors, such as aromatic phytoalexins or salicylic acid, may be involved in resistance to F. thapsinum.