The immune receptor BNT1 is involved in Myzus persicae infestation of Arabidopsis

MICAELA Y. PEPPINO MARGUTTI; SILVA-SANZANA CHRISTIAN; PALOMEQUE JULIETA; HERRERA VASQUEZ ARIEL; BLANCO-HERRERA FRANCISCA; CECCHINI NM

Congreso; LVIII Annual Meeting of the Argentine Society for Biochemistry and Molecular Biology Research; 2022

Nucleotide-binding leucine-rich repeat receptors (NLRs) are key sensors of the plant immune system, conferring resistance todiseases caused by diverse pathogens. NLRs have been found to act in several compartments inside the cell. However, NLRs havenever been described as functioning from plastids, which are essential organelles for a successful defense against pathogens.Interestingly, we have recently found that one splice variant of the Arabidopsis NLR receptor BNT1 displays a functional plastidtargeting signal. The BNT1.1 variant localizes to the cytoplasm while BNT1.2 is targeted to the plastid envelope. Thus, thedifferential activation of the BNT1 isoforms could play distinctive roles in plant defense responses against pathogens. Here, weanalyzed the level of the BNT1.1 and BNT1.2 transcripts in different tissues and under multiple biotic interactions. We found thatBNT1.2 shows the highest expression in most of the leaf tissues and conditions tested. However, in response to the aphid Myzuspersicae infestation the BNT1.1 variant was specifically induced in vascular tissue. Moreover, aphid-responsive marker geneexpression was altered in BNT1 loss-of-function plants. Taking this into account, we tested the performance of M. persicae in WTand bnt1 mutant plants. Remarkably, the Electrical Penetrations Graphs Assays showed that, among the 120 feeding activitiestested, the aphid spent more time ingesting sap from the phloem of bnt1 mutant. This strongly suggests that the aphid’s performanceis higher in the bnt1 null-mutant than in WT plants. However, the Choice Assays revealed that aphids preferred WT over bnt1plants. Together, our results might indicate a specific requirement for the cytoplasm or chloroplast located BNT1 at different stagesof the aphid infestation. Future experiments complementing bnt1 mutant with each of the variants will shed light into this attractivepossibility.