Rhomboid-type serine protease that catalyzes intramembrane proteolysis (PubMed:22416142, PubMed:22738221). Required for correct root growth, floral development, fertility and photoprotection (PubMed:22416142). May be involved in TIC22 processing during its import and in AOS accumulation in the chloroplast membrane (PubMed:22738221). Localizes probably to the inner membrane. Expressed in roots, cotyledons, leaves, seedlings, stems, flowers and immatures siliques. Up-regulated by cold during seedling germination. Longer roots and increased number of lateral roots (PubMed:22416142). No effect on the appearance of plants or time of flowering (PubMed:22416142, PubMed:22738221). Reduced fertility (PubMed:22416142). Rbl10 and rbl11 double mutants have no visible phenotype (PubMed:22738221). Belongs to the peptidase S54 family.