Abstract
The aim of this study was to evaluate the putative role of the sucrosyl-galactosides, loliose [alpha-D-Gal (1,3) alpha-D-Glc (1,2) beta-D-Fru] and raffinose [alpha-D-Gal (1,6) alpha-D-Glc (1,2) beta-D-Fru], in drought tolerance of perennial ryegrass and to compare it with that of fructans. To that end, the loliose biosynthetic pathway was first established and shown to operate by a UDP-Gal: sucrose (Suc) 3-galactosyltransferase, tentatively termed loliose synthase. Drought stress increased neither the concentrations of loliose and raffinose nor the activities of loliose synthase and raffinose synthase (EC 2.4.1.82). Moreover, the concentrations of the raffinose precursors, myoinositol and galactinol, as well as the gene expressions of myoinositol 1-phosphate synthase (EC 5.5.1.4) and galactinol synthase (EC 2.4.1.123) were either decreased or unaffected by drought stress. Taken together, these data are not in favor of an obvious role of sucrosyl-galactosides in drought tolerance of perennial ryegrass at the vegetative stage. By contrast, drought stress caused fructans to accumulate in leaf tissues, mainly in leaf sheaths and elongating leaf bases. This increase was mainly due to the accumulation of long-chain fructans (degree of polymerization > 8) and was not accompanied by a Suc increase. Interestingly, Suc but not fructan concentrations greatly increased in drought-stressed roots. Putative roles of fructans and sucrosyl-galactosides are discussed in relation to the acquisition of stress tolerance.
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Claims 10
Claim · model-written summary
Loliose biosynthesis operated through a UDP-Gal:sucrose 3-galactosyltransferase.
- Taxon
- Perennial Ryegrass
Lolium perennet0 - Gene
- UDP-Gal: sucrose (Suc) 3-galactosyltransferasee0
- Outcome
- loliose biosynthetic pathwaye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“loliose biosynthetic pathway was first established and shown to operate by a UDP-Gal: sucrose (Suc) 3-galactosyltransferase, tentatively termed loliose synthase”
t0“Perennial Ryegrass”
Claim · model-written summary
Drought did not increase loliose and raffinose concentrations.
- Taxon
- Perennial RyegrassLolium perennet0
- Treatment
- Drought stresse0
- Outcome
- concentrations of loliose and raffinosee0
- Direction
- increased neithere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Drought stress increased neither the concentrations of loliose and raffinose nor the activities of loliose synthase and raffinose synthase”
t0“Perennial Ryegrass”
Claim · model-written summary
Drought did not increase loliose synthase and raffinose synthase activities.
- Taxon
- Perennial RyegrassLolium perennet0
- Treatment
- Drought stresse0
- Outcome
- activities of loliose synthase and raffinose synthasee0
- Direction
- increased neithere0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Drought stress increased neither the concentrations of loliose and raffinose nor the activities of loliose synthase and raffinose synthase”
t0“Perennial Ryegrass”
Claim · model-written summary
Drought decreased or did not affect myoinositol and galactinol concentrations.
- Taxon
- Perennial RyegrassLolium perennet0
- Treatment
- drought stresse0
- Outcome
- concentrations of the raffinose precursors, myoinositol and galactinole0
- Direction
- decreased or unaffectede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“concentrations of the raffinose precursors, myoinositol and galactinol, as well as the gene expressions of myoinositol 1-phosphate synthase (EC 5.5.1.4) and galactinol synthase (EC 2.4.1.123) were either decreased or unaffected by drought stress”
t0“Perennial Ryegrass”
Claim · model-written summary
Drought decreased or did not affect expression of myoinositol 1-phosphate synthase and galactinol synthase.
- Taxon
- Perennial RyegrassLolium perennet0
- Treatment
- drought stresse0
- Gene
- myoinositol 1-phosphate synthase (EC 5.5.1.4) and galactinol synthase (EC 2.4.1.123)e0
- Outcome
- gene expressionse0
- Direction
- decreased or unaffectede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“gene expressions of myoinositol 1-phosphate synthase (EC 5.5.1.4) and galactinol synthase (EC 2.4.1.123) were either decreased or unaffected by drought stress”
t0“Perennial Ryegrass”
Claim · model-written summary
Drought caused fructan accumulation in leaves, mainly sheaths and elongating leaf bases.
- Taxon
- Perennial RyegrassLolium perennet0
- Organ / stage
- leaf sheaths and elongating leaf basese0
- Treatment
- drought stresse0
- Outcome
- fructanse0
- Direction
- accumulatee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“drought stress caused fructans to accumulate in leaf tissues, mainly in leaf sheaths and elongating leaf bases”
t0“Perennial Ryegrass”
Claim · model-written summary
Long-chain fructan accumulation accounted mainly for the drought response.
- Taxon
- Perennial RyegrassLolium perennet0
- Outcome
- accumulation of long-chain fructanse0
- Qualifier
- degree of polymerization > 8e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“This increase was mainly due to the accumulation of long-chain fructans (degree of polymerization > 8)”
t0“Perennial Ryegrass”
Claim · model-written summary
Sucrose did not increase with fructans in leaf tissue.
- Taxon
- Perennial RyegrassLolium perennet0
- Treatment
- Drought Stresst1
- Outcome
- Suce0
- Direction
- not accompanied by a Suc increasee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“was not accompanied by a Suc increase”
t0“Perennial Ryegrass”
t1“Drought Stress”
Claim · model-written summary
Sucrose increased greatly in drought-stressed roots.
- Taxon
- Perennial RyegrassLolium perennet0
- Organ / stage
- rootse0
- Treatment
- drought-stressede0
- Outcome
- Suce0
- Direction
- greatly increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Suc but not fructan concentrations greatly increased in drought-stressed roots”
t0“Perennial Ryegrass”
Claim · model-written summary
Fructan concentrations did not increase in drought-stressed roots.
- Taxon
- Perennial RyegrassLolium perennet0
- Treatment
- drought-stressede0
- Outcome
- fructan concentrationse0
- Direction
- note0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Suc but not fructan concentrations greatly increased in drought-stressed roots”
t0“Perennial Ryegrass”
The same questions in other papers
drought · molecular: metabolites · Lolium perenne (perennial ryegrass)Positive and negative results
1 paper in the same direction as this paper · 1 in the opposite direction
- negative
- positive
Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.