Abstract
Plants often utilize nucleotide-binding leucine-rich repeat (NLR) proteins to perceive pathogen infections and trigger a hypersensitive response (HR). The endosomal sorting complex required for transport (ESCRT) machinery is a conserved multisubunit complex that is essential for the biogenesis of multivesicular bodies and cargo protein sorting. VPS23 is a key component of ESCRT-I and plays important roles in plant development and abiotic stresses. ZmVPS23L, a homolog of VPS23-like in maize (Zea mays), was previously identified as a candidate gene in modulating HR mediated by the autoactive NLR protein Rp1-D21 in different maize populations. Here, we demonstrate that ZmVPS23L suppresses Rp1-D21-mediated HR in maize and Nicotiana benthamiana. Variation in the suppressive effect of HR by different ZmVPS23L alleles was correlated with variation in their expression levels. ZmVPS23 also suppressed Rp1-D21-mediated HR. ZmVPS23L and ZmVPS23 predominantly localized to endosomes, and they physically interacted with the coiled-coil domain of Rp1-D21 and mediated the relocation of Rp1-D21 from the nucleo-cytoplasm to endosomes. In summary, we demonstrate that ZmVPS23L and ZmVPS23 are negative regulators of Rp1-D21-mediated HR, likely by sequestrating Rp1-D21 in endosomes via physical interaction. Our findings reveal the role of ESCRT components in controlling plant NLR-mediated defense responses.