scholarly journals 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)

1994 ◽  
Vol 105 (4) ◽  
pp. 1335-1345 ◽  
Author(s):  
M. Bachmann ◽  
P. Matile ◽  
F. Keller
Keyword(s):  
Cold Acclimation ◽  
Chain Elongation ◽  
Raffinose Family Oligosaccharides ◽  
Ajuga Reptans

Vacuolar chain elongation of raffinose oligosaccharides in Ajuga reptans

2000 ◽  
Vol 27 (9) ◽  
pp. 743 ◽  
Author(s):  
Renate Braun ◽  
Felix Keller
Keyword(s):  
Osmotic Shock ◽  
Subcellular Location ◽  
Assimilate Transport ◽  
Chain Elongation ◽  
Raffinose Family Oligosaccharides ◽  
Raffinose Oligosaccharides ◽  
Ajuga Reptans ◽  
Key Enzyme ◽  
Autumn And Winter ◽  
Long Chain

This paper originates from a presentation at the International Conference on Assimilate Transport and Partitioning, Newcastle, NSW, August 1999 Galactan : galactan galactosyltransferase (GGT) is the key enzyme responsible for the accumulation of long-chain raffinose family oligosaccharides (RFOs; α-D-galn(1,6) α-D-glc(1,2) β-D-fru) in Ajuga reptans L. leaves during autumn and winter. The exact subcellular location of GGT is not known and its elucidation was the aim of this paper. A method for the isolation of vacuoles from A. reptans mesophyll protoplasts was developed using a pH and osmotic shock to rupture the plasma membrane selectively. By comparing protoplasts with vacuoles, GGT was confirmed to be a vacuolar enzyme. By comparing vacuoles with tonoplast vesicles and cell sap fractions, GGT was further shown to reside in the cell sap and not in the tonoplast. These findings suggest the need for a tonoplast-bound mechanism for the transport of short-chain RFOs such as stachyose or raffinose into the vacuole for subsequent chain elongation.

scholarly journals Expression of an α-Galactosidase Gene in Petunia is Upregulated during Low-temperature Deacclimation

2004 ◽  
Vol 129 (4) ◽  
pp. 491-496 ◽  
Author(s):  
Joyce C. Pennycooke ◽  
Ramarao Vepachedu ◽  
Cecil Stushnoff ◽  
Michelle L. Jones
Keyword(s):  
Low Temperature ◽  
Cold Acclimation ◽  
Developmental Regulation ◽  
Freezing Stress ◽  
Plant Tolerance ◽  
Raffinose Family Oligosaccharides ◽  
Specific Expression ◽  
Practical Applications ◽  
Terminal Galactose ◽  
Acclimation Response

Previous studies of plant tolerance to low temperature have focused primarily on the cold acclimation response, the process by which plants increase their tolerance to freezing in response to low nonfreezing temperatures, while studies on the deacclimation process have been largely neglected. In some plants, cold acclimation is accompanied by an increase in raffinose family oligosaccharides (RFO). The enzyme α-galactosidase (EC 3.2.1.22) breaks down RFO during deacclimation by hydrolyzing the terminal galactose moieties. Here we describe the isolation of PhGAL, an α-galactosidase cDNA clone from Petunia (Petunia ×hybrida `Mitchell'). The putative α-galactosidase cDNA has high nucleotide sequence homology (>80%) to other known plant α-galactosidases. PhGAL expression increased in response to increased temperature and there was no evidence of developmental regulation or tissue specific expression. Increases in α-galactosidase transcript 1 hour into deacclimation corresponded with increases in α-galactosidase activity and a concomitant decrease in raffinose content, suggesting that warm temperature may regulate RFO catabolism by increasing the transcription of the α-galactosidase gene. This information has potential practical applications whereby α-galactosidase may be targeted to modify endogenous raffinose accumulation in tissues needed for freezing stress tolerance.

scholarly journals ENDOGENOUS PRODUCTION OF RAFFINOSE FAMILY OLIGOSACCHARIDES INCREASES DURING THE FIRST STAGES OF COLD ACCLIMATION IN SEVERAL WOODY PLANTS

HortScience ◽  
1992 ◽  
Vol 27 (12) ◽  
pp. 1263a-1263
Author(s):  
V. Esensee ◽  
R. Remmele ◽  
C. Stushnoff ◽  
M. McNeil
Keyword(s):  
Low Temperature ◽  
Cold Acclimation ◽  
Woody Plants ◽  
Fold Increase ◽  
High Water ◽  
Raffinose Family Oligosaccharides ◽  
Water Binding ◽  
Binding Characteristics ◽  
Endogenous Production ◽  
Field Samples

Woody plants can be induced to cold-acclimate by exposure to sublethal low temperatures, but only after the onset of vegetative maturity. We monitored seven woody plant taxa, at monthly intervals, to determine the date of vegetative maturity, freeze-killing temperature, cell membrane electrolyte leakage, and the quantity and diversity of endogenous oligosaccharides. The freeze-killing temperature changed from -5 to -7C before vegetative maturity to -15 to -20C after vegetative maturity. There was a 10-fold increase in raffinose and about a 3-fold increase in endogenous stachyose in samples that were cold-acclimated under controlled conditions. In field samples, endogenous raffinose increased from <0.02% in August to 2% to 11% in cortical stem tissues of all cold-acclimated taxa. The tetrasaccharide stachyose increased from <0.02% to 0.25% to 2.5% for similar comparisons. None of the other sugars or polyols showed similar, consistent patterns during the onset of cold acclimation. In response to low temperature, raffinose family oligosaccharides (RFOs) have previously been shown to increase substantially in cabbage, soybean, kidney bean, and Chlorella. RFOs also possess high water-binding characteristics and tend to enhance aqueous glass transitions. Accordingly, we hypothesize that the endogenous production of these oligosaccharides may play an important role in metabolic events associated with cryoprotection of critical cellular functions during low-temperature stress.

Marker Trait Association for Autumn Cold Acclimation and Growth Rhythm in Pinus sylvestris

2003 ◽  
Vol 18 (1) ◽  
pp. 29-38 ◽  
Author(s):  
Reza Yazdani ◽  
Jan-erik Nilsson ◽  
Christophe Plomion ◽  
Gaurov Mathur
Keyword(s):  
Pinus Sylvestris ◽  
Cold Acclimation ◽  
Growth Rhythm ◽  
Trait Association

Unravelling a microbial synergy to boost caproate production via carboxylates chain elongation with ethanol

2019 ◽  
Vol 26 (2) ◽  
pp. 63-71
Author(s):  
Ling Leng ◽  
Ying Wang ◽  
Peixian Yang ◽  
Takashi Narihiro ◽  
Masaru Konishi Nobu ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Volatile Fatty Acids ◽  
Microbial Consortia ◽  
Chain Elongation ◽  
Desulfovibrio Vulgaris ◽  
Rrna Gene ◽  
Selective Enrichment ◽  
Microbial Network ◽  
Cost Efficient ◽  
Rrna Gene Sequencing

Chain elongation of volatile fatty acids for medium chain fatty acids production (e.g. caproate) is an attractive approach to treat wastewater anaerobically and recover resource simultaneously. Undefined microbial consortia can be tailored to achieve chain elongation process with selective enrichment from anaerobic digestion sludge, which has advantages over pure culture approach for cost-efficient application. Whilst the metabolic pathway of the dominant caproate producer, Clostridium kluyveri, has been annotated, the role of other coexisting abundant microbiomes remained unclear. To this end, an ethanol-acetate fermentation inoculated with fresh digestion sludge at optimal conditions was conducted. Also, physiological study, thermodynamics and 16 S rRNA gene sequencing to elucidate the biological process by linking the system performance and dominant microbiomes were integrated. Results revealed a possible synergistic network in which C. kluyveri and three co-dominant species, Desulfovibrio vulgaris, Fusobacterium varium and Acetoanaerobium sticklandii coexisted. D. vulgaris and A. sticklandii (F. varium) were likely to boost the carboxylates chain elongation by stimulating ethanol oxidation and butyrate production through a syntrophic partnership with hydrogen (H2) serving as an electron messenger. This study unveils a synergistic microbial network to boost caproate production in mixed culture carboxylates chain elongation.

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