Two novel disaccharides, rutinose and methylrutinose, are involved in carbon metabolism in Datisca glomerata.
Datisca glomerata forms nitrogen-fixing root nodules in symbiosis with soil actinomycetes from the genus Frankia. Analysis of sugars in roots, nodules and leaves of D. glomerata revealed the presence of two novel compounds that were identified as alpha-L-rhamnopyranoside-(1 --> 6)-D-glucose (rutinose) and alpha-L-rhamnopyranoside-(1 --> 6)-1-O-beta-D-methylglucose (methylrutinose). Rutinose has been found previously as a/the glycoside part of several flavonoid glycosides, e.g. rutin, also of datiscin, the main flavonoid of Datisca cannabina, but had not been reported as free sugar. Time course analyses suggest that both rutinose and methylrutinose might play a role in transient carbon storage in sink organs and, to a lesser extent, in source leaves. Their concentrations show that they can accumulate in the vacuole. Rutinose, but not methylrutinose, was accepted as a substrate by the tonoplast disaccharide transporter SUT4 from Arabidopsis. In vivo (14)C-labeling and the study of uptake of exogenous sucrose and rutinose from the leaf apoplast showed that neither rutinose nor methylrutinose appreciably participate in phloem translocation of carbon from source to sink organs, despite rutinose being found in the apoplast at significant levels. A model for sugar metabolism in D. glomerata is presented.
Schubert
Maria
M
Albrecht von Haller Institute for Plant Sciences, Plant Biochemistry, Göttingen University, 37077 Göttingen, Germany.
Melnikova
Anna N
AN
Mesecke
Nikola
N
Zubkova
Elena K
EK
Fortte
Rocco
R
Batashev
Denis R
DR
Barth
Inga
I
Sauer
Norbert
N
Gamalei
Yuri V
YV
Mamushina
Natalia S
NS
Tietze
Lutz F
LF
Voitsekhovskaja
Olga V
OV
Pawlowski
Katharina
K
D039903:Actinobacteria / Q000502:physiology; D017360:Arabidopsis / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000378:metabolism; D001692:Biological Transport; D002244:Carbon / Q000378:metabolism*; D004187:Disaccharides / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000378:metabolism; D008954:Models, Biological; D009586:Nitrogen Fixation; D010944:Plants / Q000378:metabolism* / Q000382:microbiology; D053204:Root Nodules, Plant / Q000378:metabolism; D013379:Substrate Specificity; D013395:Sucrose / Q000378:metabolism; D013559:Symbiosis
D029681:Arabidopsis Proteins; D004187:Disaccharides; D026901:Membrane Transport Proteins; C512029:SUT4 protein, Arabidopsis; C550486:methylrutinose; C539209:rutinose; D013395:Sucrose; D002244:Carbon