In this study,a chlorophyll-deficient mutant e(cdm) obtained from double-haploid Chinese cabbage ‘FT’ was identified as a plastome mutant with an A-to-C base substitution in the plastid gene encoding the ribosomal protein RPS4. To furthr elucidate the function and regulatory mechanism of RPS4, a comparative proteomic analysis was conducted between cdm and ‘FT’ using the isobaric tags for relative and absolute quantitation (iTRAQ)-based strategy.