Development of a P seudomonas syringae– E utrema salsugineum pathosystem to investigate disease resistance in a stress tolerant extremophile model plant

To improve the ability to understand how plants respond to multiple and/or concurrent stresses, disease resistance was investigated in E utrema salsugineum , an extremophile model plant that is highly tolerant of abiotic stress. Compared to A rabidopsis (Col‐0), both Y ukon and S handong E utrema accessions exhibit increased resistance to P seudomonas syringae pv . tomato DC 3000 (Pst) and pv. maculicola (Psm), with S handong E utrema exhibiting greater resistance to Pst than Y ukon Eutrema . RT ‐ PCR of the EsPR1 ( Pathogenesis‐related 1 ) defence marker gene confirmed RNA ‐Seq data that healthy S handong E utrema constitutively expresses EsPR1 . The data suggests that S handong E utrema exists in a highly primed state of defence preparedness, as it displays heightened resistance compared to defence‐primed natural accessions of A rabidopsis (Can‐0, Bur‐0). Pathogen‐triggered PR 1 expression was delayed in Y ukon E utrema ; however, these plants were resistant to Pst suggesting that Y ukon E utrema employs a PR 1 ‐independent mechanism to resist Pst. This study demonstrates that E utrema is an excellent model to investigate biotic stress tolerance. The E utrema– P . syringae pathosystem will facilitate future studies to understand how this extremophile tolerates both abiotic and biotic stress, and will allow exploration of the interplay of these responses to inform efforts to improve stress tolerance in crops.