Responses to temperature shocks in Zymoseptoria tritici reveal specific transcriptional reprogramming and novel candidate genes for thermal adaptation

The transcriptomic response of Zymoseptoria tritici IPO323 spores under heat and cold shock. ​​The pre-culture of the reference strain IPO323 was prepared as described previously for heat and cold shock response phenotyping. We then investigated the transcriptomic response of IPO323 under two experimental conditions: i) A “shock” treatment, where 25 mL spore suspensions (7.5 x 10⁵ spores/mL) were incubated for 15 hours at either 30°C (heat shock), 0°C (cold shock), or 18°C (control), with three replicates for each condition. ii) A “shock and recovery” treatment, where 25 mL spore suspensions were exposed to 15 hours at 0°C, 30°C, or 18°C, followed by an additional 75 hours at 18°C, with three replicates per condition. For each experiment, we transferred 2 mL of spore suspension, centrifuged the samples at approximately 9400g for 2 minutes to remove the media, and immediately flash-froze the spore pellets before storing them at -80°C. The frozen samples were sent for RNA extraction and sequencing to Biomarker Technologies GmbH (BMKgene, Münster, Germany). The sequencing was performed with Illumina NovaSeq X, pair-end 150bp reads.