Yellow barley xan-m mutants are deficient in the motor unit SECA1 of the SEC1 translocase system
Main conclusion: Chloroplast protein transport depends on the SEC1 translocase. Barley xan-m mutants, deficient in SECA1, lack chlorophyll and die as seedlings. Their yellow phenotype indicates that carotenoid chemistry is less SEC1-dependent. Chloroplast proteins encoded by genes located in the cell nucleus need to be transported across up to three chloroplast membranes to find its correct locati