S-Methylmethionine plays a major role in phloem sulfur transport and is synthesized by a novel type of methyltransferase. - Bourgis,F..; Roje,S..; Nuccio,M..L..; Fisher,D..B..; Tarczynski,M..C..; Li,C..; Herschbach,C..; Rennenberg,H..; Pimenta,M..J..; Shen,T.-L..; Gage,D..A..; Hanson,A..D.. (Plant Cell, 1999)