Expression of Leaf Spot Induced Resistance Gene-Like Sequences in Buffalograss
Bimal S. Amaradasa, Keenan Amundsen

American buffalograss [Buchloƫ dactyloides(Nutt.)Engelm. syn. Bouteloua dactyloides (Nutt.) Columbus] is a drought, heat and cold tolerant United States native turfgrass species. Leaf spot disease caused by Curvularia inaequalisnegatively impacts buffalograss visual quality. Sevencandidate resistance gene-likesequenceshave been previously identified in buffalograss based on similarity to known resistance genes.Here, the expression of these seven genes were evaluated in two leaf spot susceptible (Prestige and NE-BFG-7-3453-50) and two resistant (95-55 and NEBFG- 7-3459-17) buffalograss lines when challenged with C. inaequalis. Real-time quantitative PCR assays were used to detect expression of the sequences on eachbuffalograss line. Four of the sequences were expressed in all buffalograss lines.One sequence had higher expression in both resistant lines and another had higher expression in 95-55 when challenged with the pathogen.Compared to uninoculated controls, inoculated susceptible lines did not show a change in expression of resistance gene-like sequences. Inoculated resistant lines had higher expression of the tested resistance gene-like sequences than the susceptible lines. Expression of these genes was elevated in uninoculated plants and may contribute to the innate immunity to leaf spot disease of the resistant lines.

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