Arabis nemorensis and Arabis sagittata strong response to submergence stress contrasted with Arabidopsis thaliana

Abiotic stress, such as submergence or flooding, poses a significant threat to plant species, especially those inhabiting extreme environments. This study investigates the physiological and molecular responses of two Arabis species, Arabis nemorensis and Arabis sagittata, to submergence stress. Both species demonstrated remarkable resilience, with an 85% mean survival rate after six weeks of submergence. We conducted a comparative analysis of the Arabis species and the Arabidopsis thaliana ecotype Col-0 following a one-week submergence to examine their molecular responses. Our findings showed 7,234 DEGs in the Arabis species when analyzed independently of Col-0, and 10,105 DEGs in the presence of Col-0. The study identified distinct gene functions in response to submergence. Arabis sagittata exhibited significant upregulation of genes related to submergence hypoxia and cellular response to abscisic acid, while Arabis nemorensis showed a marked downregulation in genes associated with chlorophyll synthesis and photosynthesis-related functions. In the presence of Col-0, stress-related functions, such as callose deposition important for plant defense, were upregulated in Arabis nemorensis. In Col-0, leaf senescence and defense responses were upregulated, whereas oxygen-containing compound metabolism was upregulated across all three species. We then check miRNA response to submergence; we identified 10 miRNAs were specifically expressed in Arabis nemorensis during submergence. However, when comparing the miRNA expression profiles between Arabis nemorensis and Arabis sagittata, no differentially expressed miRNAs were identified, this suggests that A. nemorensis has unique miRNAs responding to submergence, these miRNAs do not exhibit significant differences in expression levels between the two Arabis species under submergence. Overall, these results suggest that Arabis species activate distinct functional pathways to cope with submergence, employing unique mechanisms to withstand stress.