Abstract
The onset of leaf senescence is regulated by a complex mechanism involving positive and negative regulators. Among positive regulators, jasmonic acid (JA) accumulates in senescing leaves and the JA-insensitive coi1-1 mutant displays delayed leaf senescence in Arabidopsis. A strong activated expression of the gene coding for the JA-biosynthetic beta-oxidation enzyme 3-ketoacyl-CoA thiolase 2 (KAT2) in natural and dark-induced senescing leaves of Arabidopsis thaliana is reported here. By using KAT2::GUS and KAT2::LUC transgenic plants, it was observed that dark-induced KAT2 activation occurred both in excised leaves as well as in whole darkened plants. The KAT2 activation associated with dark-induced senescence occurred soon after a move to darkness, and it preceded the detection of symptoms and the expression of senescence-associated gene (SAG) markers. Transgenic plants with reduced expression of the KAT2 gene showed a significant delayed senescence both in natural and dark-induced processes. The rapid induction of the KAT2 gene in senescence-promoting conditions as well as the delayed senescence phenotype and the reduced SAG expression in KAT2 antisense transgenic plants, point to KAT2 as an essential component for the timely onset of leaf senescence in Arabidopsis.
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Claims 8
Claim · model-written summary
KAT2 expression was strongly activated in naturally and dark-induced senescing Arabidopsis leaves.
- Taxon
- Arabidopsis thaliana
Arabidopsis thalianae0 - Organ / stage
- senescing leavese0
- Gene
- 3-ketoacyl-CoA thiolase 2 (KAT2)e0
- Outcome
- activated expressione0
- Direction
- activatede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A strong activated expression of the gene coding for the JA-biosynthetic beta-oxidation enzyme 3-ketoacyl-CoA thiolase 2 (KAT2) in natural and dark-induced senescing leaves of Arabidopsis thaliana is reported here”
Claim · model-written summary
Dark-induced KAT2 activation occurred in excised leaves.
- Taxon
- ArabidopsisArabidopsist0
- Organ / stage
- excised leavese0
- Gene
- KAT2e0
- Outcome
- KAT2 activatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“dark-induced KAT2 activation occurred both in excised leaves as well as in whole darkened plants”
t0“Arabidopsis”
Claim · model-written summary
Dark-induced KAT2 activation occurred in whole darkened plants.
- Taxon
- ArabidopsisArabidopsist0
- Organ / stage
- whole darkened plantse0
- Gene
- KAT2e0
- Outcome
- KAT2 activatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“dark-induced KAT2 activation occurred both in excised leaves as well as in whole darkened plants”
t0“Arabidopsis”
Claim · model-written summary
KAT2 activation followed darkness promptly and preceded senescence symptoms and SAG marker expression.
- Taxon
- ArabidopsisArabidopsist0
- Gene
- KAT2e0
- Outcome
- KAT2 activatione0
- Qualifier
- preceded the detection of symptoms and the expression of senescence-associated gene (SAG) markerse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The KAT2 activation associated with dark-induced senescence occurred soon after a move to darkness, and it preceded the detection of symptoms and the expression of senescence-associated gene (SAG) markers”
t0“Arabidopsis”
Claim · model-written summary
Reduced KAT2 expression significantly delayed natural senescence.
- Taxon
- ArabidopsisArabidopsist0
- Treatment
- reduced expression of the KAT2 genee0
- Gene
- KAT2e0
- Outcome
- senescencee0
- Direction
- delayede0
- Qualifier
- naturale0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Transgenic plants with reduced expression of the KAT2 gene showed a significant delayed senescence both in natural and dark-induced processes”
t0“Arabidopsis”
Claim · model-written summary
Reduced KAT2 expression significantly delayed dark-induced senescence.
- Taxon
- ArabidopsisArabidopsist0
- Treatment
- reduced expression of the KAT2 genee0
- Gene
- KAT2e0
- Outcome
- senescencee0
- Direction
- delayede0
- Qualifier
- dark-induced processese0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Transgenic plants with reduced expression of the KAT2 gene showed a significant delayed senescence both in natural and dark-induced processes”
t0“Arabidopsis”
Claim · model-written summary
KAT2 antisense plants had reduced senescence-associated gene expression.
- Taxon
- ArabidopsisArabidopsist0
- Material
- KAT2 antisense transgenic plantse0
- Gene
- KAT2e0
- Outcome
- SAG expressione0
- Direction
- reducede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the delayed senescence phenotype and the reduced SAG expression in KAT2 antisense transgenic plants”
t0“Arabidopsis”
Claim · model-written summary
The authors identify KAT2 as essential for timely onset of leaf senescence.
- Taxon
- ArabidopsisArabidopsise0
- Gene
- KAT2e0
- Outcome
- timely onset of leaf senescencee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“point to KAT2 as an essential component for the timely onset of leaf senescence in Arabidopsis”
The same questions in other papers
transgenic · quality: postharvest · ArabidopsisPositive and negative results
3 papers in the same direction as this paper · 2 in the opposite direction
- positive
- positive
- negative
2 papers more in this group
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