Divergent sequences of tetraspanins enable plants to specifically recognize microbe-derived extracellular vesicles

Abstract

AbstractExtracellular vesicles (EVs) are important for cell-to-cell communication in animals. EVs also play important roles in plant–microbe interactions, but the underlying mechanisms remain elusive. Here, proteomic analyses of EVs from the soybean (Glycine max) root rot pathogenPhytophthora sojaeidentify the tetraspanin family proteins PsTET1 and PsTET3, which are recognized byNicotiana benthamianato trigger plant immune responses. Both proteins are required for the full virulence ofP. sojae. The large extracellular loop (EC2) of PsTET3 is the key region recognized byN. benthamianaand soybean cells in a plant receptor-like kinase NbSERK3a/b dependent manner. TET proteins from oomycete and fungal plant pathogens are recognized byN. benthamianathus inducing immune responses, whereas plant-derived TET proteins are not due to the sequence divergence of sixteen amino acids at the C-terminal of EC2. This feature allows plants to distinguish self and non-self EVs to trigger active defense responses against pathogenic eukaryotes.