Direct interference with rhamnogalacturonan I biosynthesis in Golgi vesicles.
Pectin is a class of complex cell wall polysaccharides with multiple roles during cell development. Assigning specific functions to particular polysaccharides is in its infancy, in part, because of the limited number of mutants and transformants available with modified pectic polymers in their walls. Pectins are also important polymers with diverse applications in the food and pharmaceutical industries, which would benefit from technology for producing pectins with specific functional properties. In this report, we describe the generation of potato (Solanum tuberosum L. cv Posmo) tuber transformants producing pectic rhamnogalacturonan I (RGI) with a low level of arabinosylation. This was achieved by the expression of a Golgi membrane-anchored endo-alpha-1,5-arabinanase. Sugar composition analysis of RGI isolated from transformed and wild-type tubers showed that the arabinose content was decreased by approximately 70% in transformed cell walls compared with wild type. The modification of the RGI was confirmed by immunolabeling with an antibody recognizing alpha-1,5-arabinan. This is the first time, to our knowledge, that the biosynthesis of a plant cell wall polysaccharide has been manipulated through the action of a glycosyl hydrolase targeted to the Golgi compartment.
Skjøt
Michael
M
Biotechnology Group, Danish Institute of Agricultural Sciences, Thorvaldsensvej 40, 1871 Copenhagen, Denmark.
Pauly
Markus
M
Bush
Maxwell S
MS
Borkhardt
Bernhard
B
McCann
Maureen C
MC
Ulvskov
Peter
P
D002473:Cell Wall / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic; D006026:Glycoside Hydrolases / Q000235:genetics / Q000378:metabolism; D006056:Golgi Apparatus / Q000378:metabolism*; D010368:Pectins / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012799:Sialyltransferases / Q000235:genetics / Q000378:metabolism; D011198:Solanum tuberosum / Q000201:enzymology / Q000235:genetics*
D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; C042491:rhamnogalacturonan I; D010368:Pectins; D012799:Sialyltransferases; D006026:Glycoside Hydrolases; C082526:arabinan endo-1,5-alpha-L-arabinosidase