Priming against pathogens mediated by the chromatin remodeler mom1. ICAR 2021 virtual meeting.

MIRANDA DE LA TORRE, JULIAN; PEPPINO MARGUTTI, M.; ALVAREZ, ME; CECCHINI, NM

SEATTLE (VIRTUAL)

Congreso; ICAR 2021. 31st INTERNATIONAL CONFERENCE ON ARABIDOPSIS RESEARCH; 2021

North American Arabidopsis Steering Committee (NAASC)

Plants systemic resistance programs against pathogens are usually associated with an immunological memory or priming. Despitenot showing constitutive defenses, the primed state allows for a more efficient response to recurrent infections. Priming mayinvolve epigenetic modifications for a predisposition to a rapid and/or strong transcriptional activation of defense genes. Thechromatin remodeler "Morpheus´molecule 1" (MOM1) was recently proposed as a priming factor associated with activation ofdefenses during aging in Arabidopsis. Here, we analyzed the involvement of MOM1 in the establishment of priming. We found that,in sterile and non-stressful growth conditions, mom1 mutants show increased basal expression of important immune receptor geneswithout constitutive induction of resistance-associated marker genes. Interestingly, mom1 is also more susceptible to inducesystemic resistance in response to the priming inducers azelaic acid (AZA) and aminobutyric acid (BABA). Consistent with this treatments with AZA or BABA decreased systemic MOM1 transcript levels in wild-type plants. Moreover, transgenic plants thatexpress a minimal but functional version of MOM1 (mini-MOM1) show reduced systemic defenses triggered by these inducers.Together, our results strongly suggest that MOM1 is a chromatin regulator that can control defenses priming by modulating thebasal levels and/or propensity of the plant to activate central immune receptor genes.