Expressing multiple genes from a single transcript in algae and plants

A plant transformed with a polycistronic plant locus comprising genes encoding polycistronically co-expressed exogenous proteins, the genes sharing a single promoter, wherein the locus is transcribed in the plant as a corresponding mRNA comprising open reading frames (ORFs) for each of the exogenous proteins and a single poly(A) tail, wherein the ORFs comprise an upstream ORF and a downstream ORF encoding first and second proteins, respectfully, wherein translation of each of the upstream and downstream ORFs is regulated by corresponding upstream and downstream translation initiation sites, that are Kozak-like sequences, tuned to effect a predetermined ratio, that is 3:1 or 0.5:1, of the first and second proteins.