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

The Russian wheat aphid, Diuraphis noxia, is a major global pest of cereal crops and has developed virulence to D. noxia-resistant wheat varieties. With scant molecular information about D. noxia available, this study was initiated to generate a molecular dataset and to investigate transcriptomic alterations in different North American D. noxia biotypes in response to different D. noxia resistance (R) genes in wheat. We report the first RNAseq transcriptomic profiles of D. noxia biotype 1, which is avirulent to the Dn4 wheat R gene and biotype 2, which is virulent to Dn4 and avirulent to the Dn7 R gene. More than 20 millions reads/sample were generated from 18 samples (3 biological replicates each consisting of 2 biotype x 3 R gene interactions) and >64% of these reads passed quality control. 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 was differentially expressed in the two biotypes feeding on wheat varieties containing Dn4, Dn7, or a susceptible control variety with no R genes. A comparative analysis of biotype 1 and 2 genes differentially expressed from feeding on susceptible control plants with those expressed when feeding on biotype 1 resistant, biotype 2 susceptible plants containing Dn4 yielded a group of genes that will be useful as potential targets for devising novel strategies for D. noxia pest management.