Abstract
In wheat (Triticum aestivum) seedlings subjected to a mild water stress (water potential of -0.3 MPa), the leaf-elongation rate was reduced by one-half and the mitotic activity of mesophyll cells was reduced to 42% of well-watered controls within 1 d. There was also a reduction in the length of the zone of mesophyll cell division to within 4 mm from the base compared with 8 mm in control leaves. However, the period of division continued longer in the stressed than in the control leaves, and the final cell number in the stressed leaves reached 85% of controls. Cyclin-dependent protein kinase enzymes that are required in vivo for DNA replication and mitosis were recovered from the meristematic zone of leaves by affinity for p13(suc1). Water stress caused a reduction in H1 histone kinase activity to one-half of the control level, although amounts of the enzyme were unaffected. Reduced activity was correlated with an increased proportion of the 34-kD Cdc2-like kinase (an enzyme sharing with the Cdc2 protein of other eukaryotes the same size, antigenic sites, affinity for p13(suc1), and H1 histone kinase catalytic activity) deactivated by tyrosine phosphorylation. Deactivation to 50% occurred within 3 h of stress imposition in cells at the base of the meristematic zone and was therefore too fast to be explained by a reduction in the rate at which cells reached mitosis because of slowing of growth; rather, stress must have acted more immediately on the enzyme. The operation of controls slowing the exit from the G1 and G2 phases is discussed. We suggest that a water-stress signal acts on Cdc2 kinase by increasing phosphorylation of tyrosine, causing a shift to the inhibited form and slowing cell production.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 10
Claim · model-written summary
Mild water stress halved wheat leaf elongation within one day.
- Taxon
- wheat
Triticum aestivume0 - Treatment
- mild water stress (water potential of -0.3 MPa)e0
- Outcome
- leaf-elongation ratee0
- Direction
- reducede0
- Value
- one-halfe0
- Comparator
- well-watered controlse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In wheat (Triticum aestivum) seedlings subjected to a mild water stress (water potential of -0.3 MPa), the leaf-elongation rate was reduced by one-half and the mitotic activity of mesophyll cells was reduced to 42% of well-watered controls within 1 d.”
Claim · model-written summary
Mild water stress reduced mesophyll mitotic activity to 42% of controls within one day.
- Taxon
- wheatTriticum aestivume0
- Treatment
- mild water stress (water potential of -0.3 MPa)e0
- Outcome
- mitotic activity of mesophyll cellse0
- Direction
- reducede0
- Value
- 42%e0
- Comparator
- well-watered controlse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In wheat (Triticum aestivum) seedlings subjected to a mild water stress (water potential of -0.3 MPa), the leaf-elongation rate was reduced by one-half and the mitotic activity of mesophyll cells was reduced to 42% of well-watered controls within 1 d.”
Claim · model-written summary
Water stress shortened the mesophyll division zone to 4 mm versus 8 mm in controls.
- Taxon
- wheatTriticum aestivumt0
- Outcome
- length of the zone of mesophyll cell divisione0
- Direction
- reductione0
- Value
- 4 mme0
- Qualifier
- 8 mme0
- Comparator
- control leavese0
Not reportedTreatment
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“There was also a reduction in the length of the zone of mesophyll cell division to within 4 mm from the base compared with 8 mm in control leaves.”
t0“Wheat”
Claim · model-written summary
Division persisted longer in stressed than control leaves.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- stressede0
- Outcome
- period of divisione0
- Direction
- longere0
- Comparator
- control leavese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the period of division continued longer in the stressed than in the control leaves”
t0“Wheat”
Claim · model-written summary
Final cell number in stressed leaves reached 85% of controls.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- stressed leavese0
- Outcome
- final cell numbere0
- Direction
- lowerinferrede0
- Value
- 85%e0
- Comparator
- controlse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the final cell number in the stressed leaves reached 85% of controls.”
t0“Wheat”
Claim · model-written summary
Water stress halved H1 histone kinase activity.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- Water stresse0
- Gene
- H1 histone kinasee0
- Outcome
- H1 histone kinase activitye0
- Direction
- reductione0
- Value
- one-halfe0
- Comparator
- control levele0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Water stress caused a reduction in H1 histone kinase activity to one-half of the control level, although amounts of the enzyme were unaffected.”
t0“Wheat”
Claim · model-written summary
Water stress did not change enzyme abundance.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- Water stresse0
- Outcome
- amounts of the enzymee0
- Direction
- unaffectede0
- Comparator
- control levele0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Water stress caused a reduction in H1 histone kinase activity to one-half of the control level, although amounts of the enzyme were unaffected.”
t0“Wheat”
Claim · model-written summary
Reduced kinase activity correlated with more Cdc2-like kinase deactivated by tyrosine phosphorylation.
- Taxon
- wheatTriticum aestivumt0
- Gene
- Cdc2-like kinasee0
- Outcome
- proportion of the 34-kD Cdc2-like kinasee0
- Direction
- increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Reduced activity was correlated with an increased proportion of the 34-kD Cdc2-like kinase (an enzyme sharing with the Cdc2 protein of other eukaryotes the same size, antigenic sites, affinity for p13(suc1), and H1 histone kinase catalytic activity) deactivated by tyrosine phosphorylation.”
t0“Wheat”
Claim · model-written summary
Kinase deactivation reached 50% within three hours of stress.
- Taxon
- wheatTriticum aestivumt0
- Treatment
- stress impositione0
- Outcome
- Deactivatione0
- Value
- 50%e0
- Qualifier
- within 3 he0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Deactivation to 50% occurred within 3 h of stress imposition in cells at the base of the meristematic zone”
t0“Wheat”
Claim · model-written summary
The authors suggest a water-stress signal increases Cdc2 kinase tyrosine phosphorylation, inhibiting the kinase and slowing cell production.
- Taxon
- wheatTriticum aestivumt0
- Gene
- Cdc2 kinasee0
- Outcome
- cell productione0
- Direction
- slowinge0
- Qualifier
- increasing phosphorylation of tyrosinee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“We suggest that a water-stress signal acts on Cdc2 kinase by increasing phosphorylation of tyrosine, causing a shift to the inhibited form and slowing cell production.”
t0“Wheat”
The same questions in other papers
drought · physiology: enzyme activity · Triticum aestivum (wheat)Positive and negative results
12 papers in the same direction as this paper · 8 in the opposite direction
- positive
- positive
- positive
17 papers more in this group
See all 21 papers →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.