Subcellular localization of BNT1 variants and their role in response to different biotic interactions

MICAELA Y. PEPPINO MARGUTTI; CHRISTIAN SILVA-SANZANA; ARIEL HERRERA-VASQUEZ; ANA PAULA CISLAGHI; JULIETA PALOMEQUE; FRANCISCO BELLINO; MARIA ELENA ALVAREZ; FRANCISCA BLANCO-HERRERA; NICOLAS MIGUEL CECCHINI

Congreso; XVI REUNIÓN DE BIOLOGÍA VEGETAL; 2023

Chilean society of plant biologists

Nucleotide-binding leucine-rich repeat receptors (NLRs) are key sensors of the plantimmune system, conferring resistance to diseases caused by diverse pathogens.NLRs have been found to act in several compartments inside the cell. However, NLRshave never been described as functioning from plastids, essential organelles for asuccessful defense against pathogens. We have recently found that the ArabidopsisNLR receptor BNT1 displays a functional plastid targeting signal. Moreover, theBNT1 gene can generate two splice variants due to the alternative transcriptionstart sites, with only one the presence of an N-terminal signal. Importantly, wevalidated the plastid envelope or cytoplasm locations for each BNT1 variant. Thus,the differential activation of the BNT1 variants could play distinctive roles in plantdefense responses against pathogens. Expression analysis showed that the relativelevels of the variants are affected by bacteria and aphid attacks and differentiallyexpressed in epidermal and vascular tissues that are proposed to play an essentialrole in immunity. Consistently, bnt1 mutant plants have an altered resistance toPseudomonas sp and Myzus persicae. Our results suggest a specific requirementof BNT1 isoforms (i.e., subcellular localization and site/tissue of action) in responseto different biotic interactions.