|
PLANT PHYSIOLOGY , Vol 105, Issue 4 1335-1345, Copyright © 1994 by American Society of Plant Biologists
|
METABOLISM AND ENZYMOLOGY |
Metabolism of the Raffinose Family Oligosaccharides in Leaves of Ajuga reptans L. (Cold Acclimation, Translocation, and Sink to Source Transition: Discovery of Chain Elongation Enzyme)
M. Bachmann, P. Matile and F. Keller
Institute of Plant Biology, University of Zurich, Zollikerstrasse 107, CH-8008 Zurich, Switzerland
Ajuga reptans is a frost-hardy, perennial labiate that is known for its
high content of raffinose family oligosaccharide(s) (RFO). Seasonal
variations in soluble nonstructural carbohydrate levels in above-ground
parts of Ajuga showed that the RFO were by far the most predominant
components throughout the whole year. RFO were lowest in summer (75 mg/g
fresh weight) and highest in fall/winter (200 mg/g fresh weight), whereas
sucrose and starch were only minor components. Cold treatment (14 d at
10/3[deg]C, day/night) of plants that were precultivated under warm
conditions (25[deg]C) lowered the temperature optimum of net photosynthesis
from 16[deg] to 8[deg]C, decreased the maximum rate, and increased the
total nonstructural carbohydrate content of leaves by a factor of about 10,
mainly because of an increase of RFO. The degree of polymerization of the
RFO increased sequentially up to at least 15. A novel,
galactinol-independent galactosyltransferase enzyme was found, forming from
two molecules of RFO, the next higher and lower degree of polymerization of
RFO. The enzyme had a pH optimum of 4.5 to 5.0 and may be responsible for
RFO chain elongation. RFO were the main carbohydrates translocated in the
phloem, with stachyose being by far the most dominant form. Studies of
carbon balance during leaf development revealed a transition point between
import and export at approximately 25% maximal leaf area. RFO synthesis
could be detected even before the commencement of export, suggesting the
existence of a nonphloem-linked RFO pool even in very young leaves. Taken
together, it seems that Ajuga leaves contain two pools of RFO metabolism, a
pronounced long-term storage pool in the mesophyll, possibly also involved
in frost resistance, and a transport pool in the phloem.
This article has been cited by other articles:

|
 |

|
 |
 
S. Peters, S. G. Mundree, J. A. Thomson, J. M. Farrant, and F. Keller
Protection mechanisms in the resurrection plant Xerophyta viscosa (Baker): both sucrose and raffinose family oligosaccharides (RFOs) accumulate in leaves in response to water deficit
J. Exp. Bot.,
June 1, 2007;
58(8):
1947 - 1956.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
J. Lothier, B. Lasseur, K. Le Roy, A. Van Laere, M.-P. Prud'homme, P. Barre, W. Van den Ende, and A. Morvan-Bertrand
Cloning, gene mapping, and functional analysis of a fructan 1-exohydrolase (1-FEH) from Lolium perenne implicated in fructan synthesis rather than in fructan mobilization
J. Exp. Bot.,
June 1, 2007;
58(8):
1969 - 1983.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
M. A. Hannah, E. Zuther, K. Buchel, and A. G. Heyer
Transport and metabolism of raffinose family oligosaccharides in transgenic potato
J. Exp. Bot.,
November 1, 2006;
57(14):
3801 - 3811.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
R. Turgeon and R. Medville
Phloem Loading. A Reevaluation of the Relationship between Plasmodesmatal Frequencies and Loading Strategies
Plant Physiology,
November 1, 2004;
136(3):
3795 - 3803.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
T. J. Panikulangara, G. Eggers-Schumacher, M. Wunderlich, H. Stransky, and F. Schoffl
Galactinol synthase1. A Novel Heat Shock Factor Target Gene Responsible for Heat-Induced Synthesis of Raffinose Family Oligosaccharides in Arabidopsis
Plant Physiology,
October 1, 2004;
136(2):
3148 - 3158.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
U. Karner, T. Peterbauer, V. Raboy, David. A. Jones, C. L. Hedley, and A. Richter
myo-Inositol and sucrose concentrations affect the accumulation of raffinose family oligosaccharides in seeds
J. Exp. Bot.,
September 1, 2004;
55(405):
1981 - 1987.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
E. M. Tapernoux-Luthi, A. Bohm, and F. Keller
Cloning, Functional Expression, and Characterization of the Raffinose Oligosaccharide Chain Elongation Enzyme, Galactan:Galactan Galactosyltransferase, from Common Bugle Leaves
Plant Physiology,
April 1, 2004;
134(4):
1377 - 1387.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
C. Knop, R. Stadler, N. Sauer, and G. Lohaus
AmSUT1, a Sucrose Transporter in Collection and Transport Phloem of the Putative Symplastic Phloem Loader Alonsoa meridionalis
Plant Physiology,
January 1, 2004;
134(1):
204 - 214.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
J. C. Pennycooke, M. L. Jones, and C. Stushnoff
Down-Regulating {alpha}-Galactosidase Enhances Freezing Tolerance in Transgenic Petunia
Plant Physiology,
October 1, 2003;
133(2):
901 - 909.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
V. Amiard, A. Morvan-Bertrand, J.-P. Billard, C. Huault, F. Keller, and M.-P. Prud'homme
Fructans, But Not the Sucrosyl-Galactosides, Raffinose and Loliose, Are Affected by Drought Stress in Perennial Ryegrass
Plant Physiology,
August 1, 2003;
132(4):
2218 - 2229.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
B. Downie, S. Gurusinghe, P. Dahal, R. R. Thacker, J. C. Snyder, H. Nonogaki, K. Yim, K. Fukanaga, V. Alvarado, and K. J. Bradford
Expression of a GALACTINOL SYNTHASE Gene in Tomato Seeds Is Up-Regulated before Maturation Desiccation and Again after Imbibition whenever Radicle Protrusion Is Prevented
Plant Physiology,
March 1, 2003;
131(3):
1347 - 1359.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
T. Peterbauer, J. Mucha, L. Mach, and A. Richter
Chain Elongation of Raffinose in Pea Seeds. ISOLATION, CHARCTERIZATION, AND MOLECULAR CLONING OF A MULTIFUNCTIONAL ENZYME CATALYZING THE SYNTHESIS OF STACHYOSE AND VERBASCOSE
J. Biol. Chem.,
January 4, 2002;
277(1):
194 - 200.
[Abstract]
[Full Text]
|
 |
|

|
 |

|
 |
 
T. Peterbauer, L. B. Lahuta, A. Blochl, J. Mucha, D. A. Jones, C. L. Hedley, R. J. Gorecki, and A. Richter
Analysis of the Raffinose Family Oligosaccharide Pathway in Pea Seeds with Contrasting Carbohydrate Composition
Plant Physiology,
December 1, 2001;
127(4):
1764 - 1772.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
W. Pattanagul and M. A. Madore
Water Deficit Effects on Raffinose Family Oligosaccharide Metabolism in Coleus
Plant Physiology,
November 1, 1999;
121(3):
987 - 993.
[Abstract]
[Full Text]
|
 |
|

|
 |

|
 |
 
B. Häfliger, E. Kindhauser, and F. Keller
Metabolism of D-Glycero-D-Manno-Heptitol, Volemitol, in Polyanthus. Discovery of a Novel Ketose Reductase1
Plant Physiology,
January 1, 1999;
119(1):
191 - 198.
[Abstract]
[Full Text]
|
 |
|

|
 |

|
 |
 
D. E. Nelson, G. Rammesmayer, and H. J. Bohnert
Regulation of Cell-Specific Inositol Metabolism and Transport in Plant Salinit y Tolerance
PLANT CELL,
May 1, 1998;
10(5):
753 - 764.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
T. Peterbauer and A. Richter
Galactosylononitol and Stachyose Synthesis in Seeds of Adzuki Bean . Purification and Characterization of Stachyose Synthase
Plant Physiology,
May 1, 1998;
117(1):
165 - 172.
[Abstract]
[Full Text]
|
 |
|
|
|