TY - JOUR
T1 - α-Galactosidase is synthesized in tomato seeds during development and is localized in the protein storage vacuoles
AU - Bassel, G.W.
AU - Mullen, R.T.
AU - Bewley, J.D.
N1 - Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2001/1/1
Y1 - 2001/1/1
N2 - The localization of the enzyme α-galactosidase (EC 3.2.1.22) was investigated during its synthesis in developing tomato (Lycopersicon esculentum Mill.) cv. Trust seeds. This enzyme is also present in germinating seeds, where it is involved in the mobilization of carbohydrate reserves during and following seed germination. Subcellular fractionation of developing tomato seeds revealed that there is a cosedimentation between α-galactosidase activity and protein storage vacuoles in a density gradient, which is dependent upon the presence of membranes. A second approach to localizing this enzyme involved the transient transformation of protoplasts from developing tomato seeds. A reporter construct, coding for tomato α-galactosidase, fused N-terminally to the bacterial enzyme chloramphenicol acetyltransferase was used for transient expression. Immunofluorescence microscopy revealed a colocalization between the α-galactosidase - chloramphenicol acetyltransferase fusion protein and the α-tonoplast intrinsic protein, and a partial colocalization with the dark intrinsic protein (both vacuolar proteins). These data indicate that the protein storage vacuole is the intracellular location for α-galactosidase in developing tomato seeds.
AB - The localization of the enzyme α-galactosidase (EC 3.2.1.22) was investigated during its synthesis in developing tomato (Lycopersicon esculentum Mill.) cv. Trust seeds. This enzyme is also present in germinating seeds, where it is involved in the mobilization of carbohydrate reserves during and following seed germination. Subcellular fractionation of developing tomato seeds revealed that there is a cosedimentation between α-galactosidase activity and protein storage vacuoles in a density gradient, which is dependent upon the presence of membranes. A second approach to localizing this enzyme involved the transient transformation of protoplasts from developing tomato seeds. A reporter construct, coding for tomato α-galactosidase, fused N-terminally to the bacterial enzyme chloramphenicol acetyltransferase was used for transient expression. Immunofluorescence microscopy revealed a colocalization between the α-galactosidase - chloramphenicol acetyltransferase fusion protein and the α-tonoplast intrinsic protein, and a partial colocalization with the dark intrinsic protein (both vacuolar proteins). These data indicate that the protein storage vacuole is the intracellular location for α-galactosidase in developing tomato seeds.
UR - http://www.scopus.com/inward/record.url?partnerID=yv4JPVwI&eid=2-s2.0-0035719827&md5=1db8015615692b710713aec8f6bf8a1a
U2 - 10.1139/cjb-79-12-1417
DO - 10.1139/cjb-79-12-1417
M3 - Article
AN - SCOPUS:0035719827
SN - 0008-4026
VL - 79
SP - 1417
EP - 1424
JO - Canadian Journal of Botany
JF - Canadian Journal of Botany
IS - 12
ER -