Role of the chromatin remodeler d MOM1 in the priming against pathogens in Arabidopsis thaliana (L.) Heynh

MIRANDA DE LA TORRE JO; CECCHINI N; ALVAREZ ME

Virtual

Congreso; IV Reunión Conjunta de Sociedades de Biología de la República Argentina; 2020

Sociedades de Biología de la República Argentina

After recognition of a pathogen, plants induce local and distal defenses. Systemic resistance programs are usually associated with an immune alertness, immunological "memory" or priming. Despite not showing constitutive defenses, a primed plant responds faster and/or strongly to recurrent infections. Priming may involve an increase in immune receptors, accumulation of inactive signaling proteins and/or epigenetic modifications of chromatin that predispose to transcriptional activation of defense genes. The chromatin remodeler "Morpheus Molecule" (MOM1) was recently proposed as a primingfactor associated with the activation of defenses during aging. Here, we analyzed the role of MOM1 in the immunological "memory" of Arabidopsis.We studied thesusceptibility ofmom1mutant plantsto chemical and biological inducers of priming against pathogens. Wealso determined whether the increased pathogen resistance observed in plants lacking MOM1 is caused by aging and/or growth conditions. We found that, independently of the development stage,under optimal conditions of growth and sterilitymom1mutantplants show increased levels of immune receptors without the induction of defenses. In addition, mom1is more sensible to the priminginducers azelaic acid (AZA) and aminobutyric acid (BABA). Consistently, transgenic plants that express a minimal but functional version of MOM1 (mini-MOM1) do not respond to these inductors. Moreover, treatmentswith AZA or BABA reducedthe transcript levelsof MOM1 in wild-type plants. Together, our results position the chromatin remodeler MOM1 as a negative regulator of the priming against pathogens in Arabidopsis.