Abstract
Plants exhibit age-dependent drought responses during juvenile-to-adult phase transition. However, the specific regulatory molecular mechanisms remain unknown. In this study, juvenile apple plants exhibited better drought tolerance than adult apple plants because of the age-dependent changes in root vitality, cytokinin (CK) levels, and redox status in roots. The study uncovers CYTOKININ OXIDASE/DEHYDROGENASE5 (MdCKX5) as a negative regulator of drought tolerance in apple roots. Silencing of MdCKX5 caused CK accumulation thereby enhancing drought tolerance by increasing root vitality and preventing the accumulation of reactive oxygen species. In contrast, overexpression of MdCKX5 reduced drought tolerance in apple roots. Yeast one-hybrid, dual-luciferase and electrophoretic mobility shift assays revealed that apple transcription factor MdSPL1 directly binds to the promoters of MdCKX5 thereby repressing its expression. Overexpression of MdSPL1 in apple roots increased the CK content thereby enhancing drought tolerance. Further analysis revealed that MdMYB23, a positive CK-responsive gene, interacts with MdSPL1 to alleviate the repression of MdCKX5 expression by MdSPL1. In general, drought stress significantly downregulated MdMYB23, thereby activating the MdSPL1-mediated repression of MdCKX5 transcription by releasing the MdSPL1. This phenomenon led to enhanced drought tolerance in juvenile apple roots by increasing the CK levels. However, adult apple roots lost the capacity to activate this cascade. These findings provide new insights into the molecular mechanisms of CK-mediated age-dependent drought tolerance during the vegetative phase change in apples.
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 13
Claim · model-written summary
Juvenile apple plants had better drought tolerance than adults.
- Taxon
- apple
Malus domesticae0 - Material
- juvenile apple plantse0
- Outcome
- drought tolerancee0
- Direction
- bettere0
- Comparator
- adult apple plantse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“juvenile apple plants exhibited better drought tolerance than adult apple plants”
Claim · model-written summary
MdCKX5 negatively regulates drought tolerance in apple roots.
- Taxon
- appleMalus domesticae0
- Organ / stage
- rootse0
- Gene
- MdCKX5e0
- Outcome
- drought tolerancee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“MdCKX5) as a negative regulator of drought tolerance in apple roots”
Claim · model-written summary
MdCKX5 silencing accumulated cytokinin.
- Taxon
- appleMalus domesticat0
- Treatment
- Silencing of MdCKX5e0
- Gene
- MdCKX5e0
- Outcome
- CK accumulatione0
- Direction
- accumulatione0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Silencing of MdCKX5 caused CK accumulation”
t0“apple”
Claim · model-written summary
MdCKX5 silencing enhanced drought tolerance.
- Taxon
- appleMalus domesticat0
- Treatment
- Silencing of MdCKX5e0
- Gene
- MdCKX5e0
- Outcome
- drought tolerancee0
- Direction
- enhancinge0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Silencing of MdCKX5 caused CK accumulation thereby enhancing drought tolerance”
t0“apple”
Claim · model-written summary
MdCKX5 silencing increased root vitality.
- Taxon
- appleMalus domesticat0
- Treatment
- Silencing of MdCKX5e0
- Gene
- MdCKX5e0
- Outcome
- root vitalitye0
- Direction
- increasinge0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Silencing of MdCKX5 caused CK accumulation thereby enhancing drought tolerance by increasing root vitality”
t0“apple”
Claim · model-written summary
MdCKX5 silencing prevented reactive oxygen species accumulation.
- Taxon
- appleMalus domesticat0
- Treatment
- Silencing of MdCKX5e0
- Gene
- MdCKX5e0
- Outcome
- accumulation of reactive oxygen speciese0
- Direction
- preventinge0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Silencing of MdCKX5 caused CK accumulation thereby enhancing drought tolerance by increasing root vitality and preventing the accumulation of reactive oxygen species”
t0“apple”
Claim · model-written summary
MdCKX5 overexpression reduced drought tolerance.
- Taxon
- appleMalus domesticae0
- Treatment
- overexpression of MdCKX5e0
- Gene
- MdCKX5e0
- Outcome
- drought tolerancee0
- Direction
- reducede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“overexpression of MdCKX5 reduced drought tolerance in apple roots”
Claim · model-written summary
MdSPL1 directly binds MdCKX5 promoters and represses expression.
- Taxon
- appleMalus domesticae0
- Gene
- MdSPL1e0
- Outcome
- repressing its expressione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“apple transcription factor MdSPL1 directly binds to the promoters of MdCKX5 thereby repressing its expression”
Claim · model-written summary
MdSPL1 overexpression increased cytokinin content.
- Taxon
- appleMalus domesticae0
- Treatment
- Overexpression of MdSPL1e0
- Gene
- MdSPL1e0
- Outcome
- CK contente0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Overexpression of MdSPL1 in apple roots increased the CK content”
Claim · model-written summary
MdSPL1 overexpression enhanced drought tolerance.
- Taxon
- appleMalus domesticae0
- Treatment
- Overexpression of MdSPL1e0
- Gene
- MdSPL1e0
- Outcome
- drought tolerancee0
- Direction
- enhancinge0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Overexpression of MdSPL1 in apple roots increased the CK content thereby enhancing drought tolerance”
Claim · model-written summary
MdMYB23 interacts with MdSPL1 to alleviate MdCKX5 repression.
- Taxon
- appleMalus domesticat0
- Gene
- MdMYB23e0
- Outcome
- repression of MdCKX5 expressione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“MdMYB23, a positive CK-responsive gene, interacts with MdSPL1 to alleviate the repression of MdCKX5 expression by MdSPL1”
t0“apple”
Claim · model-written summary
Drought stress downregulated MdMYB23.
- Taxon
- appleMalus domesticat0
- Treatment
- drought stresse0
- Gene
- MdMYB23e0
- Outcome
- MdMYB23e0
- Direction
- downregulatede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“drought stress significantly downregulated MdMYB23”
t0“apple”
Claim · model-written summary
Adult apple roots lost capacity to activate the MdSPL1-MdCKX5 cascade.
- Taxon
- appleMalus domesticae0
- Organ / stage
- adult apple rootse0
- Outcome
- lost the capacity to activate this cascadee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“adult apple roots lost the capacity to activate this cascade”
The same questions in other papers
loss of function · physiology: oxidative · Malus domestica (apple)Positive and negative results
1 paper in the same direction as this paper · 2 in the opposite direction
- negative
- negative
- positive
loss of function · physiology: hormones · Malus domestica (apple)Positive and negative results
3 papers in the same direction as this paper · 1 in the opposite direction
- negative
- positive
- positive
1 paper more in this group
See all 5 papers →loss of function · tolerance: abiotic · Malus domestica (apple)Positive and negative results
4 papers in the same direction as this paper · 3 in the opposite direction
- positive
- positive
- negative
4 papers more in this group
See all 8 papers →loss of function · growth · Malus domestica (apple)Positive and negative results
4 papers in the same direction as this paper · 4 in the opposite direction
- negative
- negative
- negative
5 papers more in this group
See all 9 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.