Involved in cuticular wax formation (PubMed:16183838, PubMed:19625635). Required for the synthesis of alkanes from wax precursors (PubMed:16183838, PubMed:19625635). May play a role in acyl-CoA reduction to aldehydes (PubMed:16183838). Is repressed by FREE1 and functions downstream of FREE1 to negatively regulate multivesicular body (MVB) biogenesis and vacuolar transport (PubMed:31221737). Together with CER16/RIPR, acts as cofactor of the cytoplasmic exosome and connects the cytosolic RNA exosome to the SKI complex (PubMed:31455787). Acts as post-transcriptional gene silencing (PTGS) suppressor (PubMed:31455787, PubMed:31076735). RST1 can, like CER16/RIPR, suppress the production of small interfering RNAs (siRNAs) from the CER3 locus, which is involved in cuticule membrane and wax production, and in the typhine and sporopollenin biosynthesis of pollen (PubMed:31455787). Interacts with CER16/RIPR. Expressed in the vasculature of leaves, petioles and hypocotyls, anthers of mature flowers and siliques (PubMed:19625635). Expressed at low levels in roots and stems (PubMed:16183838). Shrunken non viable seeds due to arrested embryo development when homozygous (PubMed:16183838). Alteration in cuticular waxes with elevated amounts of cutin monomers in leaves (PubMed:16183838, PubMed:19625635). Susceptibility to the obligate biotrophic fungus E.cichoracearum and increased resistance to the necrotrophic fungi B.cinerea and A.brassicicola (PubMed:19625635).