Host and Non-host Resistance to Zymoseptoria tritici and Zymoseptoria passerinii
RNA-seq experiments were conducted to compare gene expression in host and non-host defense responses in wheat and barley inoculated with water (the control), Zymoseptoria tritici, or Zymoseptoria passerinii. The specific treatments were:Taichung29 wheat inoculated with water (susceptible control)Taichung29 wheat inoculated with Z. tritici isolate IPO323 (susceptible)Veranopolis wheat inoculated with water (Stb2 resistant control)Veranopolis wheat inoculated with Z. tritici isolate IPO323 (Stb2 resistant)Israel493 wheat inoculated with water (Stb3 resistant control)Israel493 wheat inoculated with Z. tritici isolate IPO323 (Stb3 resistant)Taichung29 wheat inoculated with Z. passerinii (non-host interaction)Kindred barley inoculated with Z. passerinii (susceptible)Kindred barley inoculated with water (susceptible control)Kindred barley inoculated with Z. tritici isolate IPO323 (non-host interaction)Peruvian barley inoculated with water (another resistant control)Peruvian barley inoculated with Z. passerinii (resistant)The inoculum was evenly hand sprayed over 14-days-old (2nd-3rd leaf stage) wheat and barley plants. Inoculated plants were enclosed in a humidity chamber draped in plastic and muslin for 72 h, then removed to normal growth chamber conditions for the duration of the experiment. Emerging leaves of wheat and barley were trimmed every 2-3 days to ensure that the inoculated leaves remained "healthy" and that only inoculated tissue was harvested. RNA samples were collected in triplicate from leaves 1, 3, 6, 10, 17, and 23 days later. The cDNA was prepared and Illumina sequenced to produce paired-end reads. RNA was extracted using the RNeasy Plant Mini kit (Qiagen). For each replicate, 1 microgram of total RNA was used to produce cDNA libraries (Purdue Genomics Core Facility, West Lafayette, IN) for RNA sequencing. The sequencing was done using the Illumina HiSeq producing 100 base paired-end (PE) reads.The study is relevant to future attempts to engineer durable resistance to these pathogens in wheat and barley by altering the action of target genes involved in defense response.