Transcriptomic Profiles of Virulent and Avirulent Diuraphis noxia feeding on D. noxia-Resistant and Susceptible Wheat

Virulent biotypes of the Russian wheat aphid, Diuraphis noxia, a global pest of wheat, are appearing globally. This study was initiated to investigate transcriptomic alterations in North American D. noxia feeding on D. noxia-susceptible and resistant wheat varieties. The study reports the first RNAseq transcriptomic profiles of D. noxia feeding on a susceptible wheat (Yuma), the near isogenic line of Yuma -‘Yumar,’ containing the Dn4 R gene, and ‘Gamtoos-R’ wheat, containing the Dn7 R gene. D. noxia North American biotype 1 is virulent to Yuma and avirulent to Yumar; biotype 2 is virulent to Yuma and Yumar and avirulent to Gamtoos-R. More than 20 millions reads/sample were generated from 18 samples (3 biological replicates each consisting of 6 biotype x R gene interactions) and >64% of these reads passed QC. Pooled sequences from all 18 samples were used to generate a de novo assembly, followed by sample-wise assembly, abundance estimation (FKPM≥1) and differential expression analysis of genes and transcripts. A large set of genes were differentially expressed in the two D. noxia biotypes feeding on wheat with different R genes. Comparative analysis of genes differentially expressed in biotypes 1 and 2 fed susceptible Yuma plants to those expressed when fed Yumar (Dn4) plants yielded genes useful for improved D. noxia management strategies.