Differential expression of BNT1 splice variants during the Arabidopsis defense responses 

PEPPINO MARGUTTI, M.; ALVAREZ, ME; CECCHINI, NM

Santa Fe (online)

Congreso; Reunión Argentina de Fisiologia Vegetal; 2021

Nucleotide-binding leucine-rich repeat receptors (NLRs) are key sensors of the plant immune system, conferring resistance to diseases. NLRs have been found to act from several compartments inside the cell. However, NLRs have never been described as functioning from plastids, which are essential organelles for a successful defense against pathogens. Interestingly, results from our group showed that the Arabidopsis NLR called BNT1 localize in this organelle. We also predicted that three variants of BNT1 could be generated by alternative splicing, with only one of them displaying a complete plastid targeting signal. Thus, the activation of different BNT1 isoforms could be related to the well-known defense responses associated to plastids. Here, we confirmed the presence of the BNT1 variants transcript and analyzed their localization. Moreover, we found that the expression of the BNT1 splice variants differentially change under conditions/treatments that affect chloroplast normal function and during the induction of defenses. Consistently, our preliminary results show that bnt1 mutant plants have an anormal resistant to pathogens and altered expression of biotic and oxidative stress marker genes. Together, our findings suggest that BNT1 immune function(s) are mediated by the plastids activity. The elucidation of the role of BNT1 variants and its regulation could represent a new paradigm to understand the function of NLRs located at different subcellular compartments.