Membrane trafficking to the protein storage vacuole （PSV） is a specialized process in seed plants. However, this trafficking mechanism to PSV is poorly understood. Here, we show that three types of Beige and Chediak...Membrane trafficking to the protein storage vacuole （PSV） is a specialized process in seed plants. However, this trafficking mechanism to PSV is poorly understood. Here, we show that three types of Beige and Chediak-Higashi （BEACH）-domain proteins contribute to both vacuolar protein transport and effector- triggered immunity （ETI）. We screened a green fluorescent seed （GFS） library of Arabidopsis mutants with defects in vesicle trafficking and isolated two allelic mutants gfs3 and gfs12 with a defect in seed pro- tein transport to PSV. The gene responsible for the mutant phenotype was found to encode a putative pro- tein belonging to group D of BEACH-domain proteins, which possess kinase domains. Disruption of other BEACH-encoding loci in the gfs12 mutant showed that BEACH homologs acted in a cascading manner for PSV trafficking. The epistatic genetic interactions observed among BEACH homologs were also found in the ETI responses of the gfs12 and gfs12 bchb-1 mutants, which showed elevated avirulent bacterial growth. The GFS12 kinase domain interacted specifically with the pleckstrin homology domain of BchCl. These results suggest that a cascade of multiple BEACH-domain proteins contributes to vacuolar protein transport and plant defense.展开更多
文摘Membrane trafficking to the protein storage vacuole （PSV） is a specialized process in seed plants. However, this trafficking mechanism to PSV is poorly understood. Here, we show that three types of Beige and Chediak-Higashi （BEACH）-domain proteins contribute to both vacuolar protein transport and effector- triggered immunity （ETI）. We screened a green fluorescent seed （GFS） library of Arabidopsis mutants with defects in vesicle trafficking and isolated two allelic mutants gfs3 and gfs12 with a defect in seed pro- tein transport to PSV. The gene responsible for the mutant phenotype was found to encode a putative pro- tein belonging to group D of BEACH-domain proteins, which possess kinase domains. Disruption of other BEACH-encoding loci in the gfs12 mutant showed that BEACH homologs acted in a cascading manner for PSV trafficking. The epistatic genetic interactions observed among BEACH homologs were also found in the ETI responses of the gfs12 and gfs12 bchb-1 mutants, which showed elevated avirulent bacterial growth. The GFS12 kinase domain interacted specifically with the pleckstrin homology domain of BchCl. These results suggest that a cascade of multiple BEACH-domain proteins contributes to vacuolar protein transport and plant defense.
