ESCRT-I Mediates FLS2 Endosomal Sorting and Plant Immunity

The plant immune receptor flagellin sensing 2 (fls2) is present at the plasma membrane and is internalized following activation of its ligand flagellin (flg22). we show that endosomal sorting complex required for transport (escrt)-i subunits play roles in fls2 endocytosis in arabidopsis. vps37-1 co-localizes with fls2 at endosomes and immunoprecipitates with the receptor upon flg22 elicitation. vps37-1 mutants are reduced in flg22-induced fls2 endosomes but not in endosomes labeled by rab5 gtpases suggesting a defect in fls2 trafficking rather than formation of endosomes. fls2 localizes to the lumen of multivesicular bodies,but this is altered in vps37-1 mutants indicating compromised endosomal sorting of fls2 by escrt-i loss-of-function. vps37-1 and vps28-2 are critical for immunity against bacterial infection through a role in stomatal closure. our findings identify that vps37-1,and likewise vps28-2,regulate late fls2 endosomal sorting and reveals that escrt-i is critical for flg22-activated stomatal defenses involved in plant immunity. © 2013 spallek et al.