Synthetic seeds are mostly derived from
Synthetic seeds are mostly derived from
Select an option to attempt
Correct Answer: Option A
Explanation
Glycosylation requires a complex membrane-bound machinery: glycosyltransferases that add specific sugar residues, sugar nucleotide transporters (to supply UDP-glucose, UDP-galactose, etc. into the ER lumen/Golgi), and chaperones for folding of glycoproteins. This entire apparatus is absent from plastids (chloroplasts, leucoplasts). Plastids CAN perform: Phosphorylation — via plastid-localised protein kinases and the photosynthetic machinery (e.g. thylakoid kinases STN7, STN8 phosphorylating LHCII proteins); Acetylation — of transit peptides and stroma enzymes; S-nitrosylation — by reactive nitrogen species in plastid stroma. Glycosylation of plastid proteins does NOT occur within the plastid — any glycoproteins imported into plastids are glycosylated in the ER before/during import.