Fig. 6.

Construct for expressing soybean ferritin extracellularly in Arabidopsis. a Mature form of soybean ferritin H-1 (Sfer H-I) was used for gene synthesis. EP: the sequence encoding extension peptide; ABCD and E, the sequences corresponding to the A to E helixes of mature ferritin. b Vector pCAMBIA1305.2 was developed by pCAMBIA (http://www.cambia.org), which has a glycine-rich protein (GRP) signal peptide for extracellular targeting. For expression construct, the catalase intron-GusPlus gene cassette in above vector was replaced by the ferritin gene; nopaline synthase (nos) polyA was the terminator. c Confirmation of construct pCAMBIA1305.2-ferritin by restriction enzyme digestion. Lanes 1 and 2, uncut and BglII-BstEII cut empty vector (1305.2), respectively; the latter was digested into two bands, including the 1980 bp GUSplus gene. Lanes 3 and 4, uncut and BglII-BstEII cut construct (pCAMBIA1305.2-ferritin), respectively; the latter was digested into two bands, including the 623 bp ferritin gene