Academia Sinica Logo

TIC236 is an essential bridge that links the chloroplast outer and inner membrane protein translocon complexes. Here, we unveil a TIC236-allied component, the chloroplast outer membrane protein CRUMPLED LEAF (CRL), absence of which impairs plastid division and induces autoimmune responses. A forward genetic screen exploring CRL function found multiple dominant TIC236 gain-of-function (tic236-gf) mutations that abolished crl-induced phenotypes. We show that CRL interacts with the transit peptides of proteins essential in plastid division, with tic236-gf mutations reinforcing their import via increased TIC236 stability. Our data shed new light on the links between plastid protein import, plastid division, and plant stress responses.