Abstract
We have identified three Arabidopsis genes with GAMYB-like activity, AtMYB33, AtMYB65, and AtMYB101, which can substitute for barley (Hordeum vulgare) GAMYB in transactivating the barley alpha-amylase promoter. We have investigated the relationships between gibberellins (GAs), these GAMYB-like genes, and petiole elongation and flowering of Arabidopsis. Within 1 to 2 d of transferring plants from short- to long-day photoperiods, growth rate and erectness of petioles increased, and there were morphological changes at the shoot apex associated with the transition to flowering. These responses were accompanied by accumulation of GAs in the petioles (GA(1) by 11-fold and GA(4) by 3-fold), and an increase in expression of AtMYB33 at the shoot apex. Inhibition of GA biosynthesis using paclobutrazol blocked the petiole elongation induced by long days. Causality was suggested by the finding that, with GA treatment, plants flowered in short days, AtMYB33 expression increased at the shoot apex, and the petioles elongated and grew erect. That AtMYB33 may mediate a GA signaling role in flowering was supported by its ability to bind to a specific 8-bp sequence in the promoter of the floral meristem-identity gene, LEAFY, this same sequence being important in the GA response of the LEAFY promoter. One or more of these AtMYB genes may also play a role in the root tip during germination and, later, in stem tissue. These findings extend our earlier studies of GA signaling in the Gramineae to include a dicot species, Arabidopsis, and indicate that GAMYB-like genes may mediate GA signaling in growth and flowering responses.
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Claims 13
Claim · model-written summary
AtMYB33, AtMYB65 and AtMYB101 substituted for barley GAMYB in promoter transactivation.
- Taxon
- Arabidopsis
Arabidopsise0 - Gene
- AtMYB33, AtMYB65, and AtMYB101e0
- Outcome
- transactivating the barley alpha-amylase promotere0
- Comparator
- barley (Hordeum vulgare) GAMYBe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“three Arabidopsis genes with GAMYB-like activity, AtMYB33, AtMYB65, and AtMYB101, which can substitute for barley (Hordeum vulgare) GAMYB in transactivating the barley alpha-amylase promoter”
Claim · model-written summary
Long-day transfer increased Arabidopsis petiole growth rate and erectness within 1 to 2 days.
- Taxon
- ArabidopsisArabidopsist0
- Organ / stage
- petiolese0
- Treatment
- long-day photoperiodse0
- Outcome
- growth rate and erectnesse0
- Direction
- increasede0
- Qualifier
- Within 1 to 2 de0
- Comparator
- short-e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Within 1 to 2 d of transferring plants from short- to long-day photoperiods, growth rate and erectness of petioles increased”
t0“Arabidopsis”
Claim · model-written summary
Long-day transfer produced shoot-apex morphological changes associated with flowering transition.
- Taxon
- ArabidopsisArabidopsist0
- Organ / stage
- shoot apexe0
- Treatment
- long-day photoperiodse1
- Outcome
- morphological changes at the shoot apex associated with the transition to floweringe0
- Comparator
- short-e1
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“there were morphological changes at the shoot apex associated with the transition to flowering”
e1“transferring plants from short- to long-day photoperiods”
t0“Arabidopsis”
Claim · model-written summary
Petiole GA(1) accumulation increased 11-fold following long-day transfer.
- Taxon
- ArabidopsisArabidopsist0
- Organ / stage
- petiolese0
- Treatment
- long-day photoperiodse1
- Outcome
- GA(1)e0
- Direction
- accumulatione0
- Value
- 11-folde0
- Comparator
- short-e1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“accumulation of GAs in the petioles (GA(1) by 11-fold and GA(4) by 3-fold)”
e1“transferring plants from short- to long-day photoperiods”
t0“Arabidopsis”
Claim · model-written summary
Petiole GA(4) accumulation increased threefold following long-day transfer.
- Taxon
- ArabidopsisArabidopsist0
- Organ / stage
- petiolese0
- Treatment
- long-day photoperiodse1
- Outcome
- GA(4)e0
- Direction
- accumulatione0
- Value
- 3-folde0
- Comparator
- short-e1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“accumulation of GAs in the petioles (GA(1) by 11-fold and GA(4) by 3-fold)”
e1“transferring plants from short- to long-day photoperiods”
t0“Arabidopsis”
Claim · model-written summary
AtMYB33 expression at the shoot apex increased after long-day transfer.
- Taxon
- ArabidopsisArabidopsist0
- Organ / stage
- shoot apexe0
- Treatment
- long-day photoperiodse1
- Gene
- AtMYB33e0
- Outcome
- expression of AtMYB33e0
- Direction
- increasee0
- Comparator
- short-e1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“an increase in expression of AtMYB33 at the shoot apex”
e1“transferring plants from short- to long-day photoperiods”
t0“Arabidopsis”
Claim · model-written summary
Paclobutrazol blocked long-day-induced petiole elongation.
- Taxon
- ArabidopsisArabidopsist0
- Treatment
- paclobutrazole0
- Outcome
- petiole elongatione0
- Direction
- blockede0
- Comparator
- long dayse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Inhibition of GA biosynthesis using paclobutrazol blocked the petiole elongation induced by long days”
t0“Arabidopsis”
Claim · model-written summary
GA treatment induced flowering under short days.
- Taxon
- ArabidopsisArabidopsist0
- Treatment
- GA treatmente0
- Outcome
- flowered in short dayse0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“with GA treatment, plants flowered in short days”
t0“Arabidopsis”
Claim · model-written summary
GA treatment increased shoot-apex AtMYB33 expression.
- Taxon
- ArabidopsisArabidopsist0
- Organ / stage
- shoot apexe0
- Treatment
- GA treatmente0
- Gene
- AtMYB33e0
- Outcome
- AtMYB33 expressione0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“with GA treatment, plants flowered in short days, AtMYB33 expression increased at the shoot apex”
t0“Arabidopsis”
Claim · model-written summary
GA treatment elongated petioles and made them erect.
- Taxon
- ArabidopsisArabidopsist0
- Treatment
- GA treatmente0
- Outcome
- petioles elongated and grew erecte0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“with GA treatment, plants flowered in short days, AtMYB33 expression increased at the shoot apex, and the petioles elongated and grew erect”
t0“Arabidopsis”
Claim · model-written summary
AtMYB33 bound an eight-base-pair sequence in the LEAFY promoter.
- Taxon
- ArabidopsisArabidopsist0
- Gene
- AtMYB33e1
- Outcome
- bind to a specific 8-bp sequence in the promoter of the floral meristem-identity gene, LEAFYe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“its ability to bind to a specific 8-bp sequence in the promoter of the floral meristem-identity gene, LEAFY”
e1“AtMYB33 may mediate a GA signaling role”
t0“Arabidopsis”
Claim · model-written summary
The same LEAFY promoter sequence was important to its GA response.
- Taxon
- ArabidopsisArabidopsist0
- Gene
- LEAFYe0
- Outcome
- GA response of the LEAFY promotere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“this same sequence being important in the GA response of the LEAFY promoter”
t0“Arabidopsis”
Claim · model-written summary
The authors suggest GAMYB-like genes may mediate GA signaling in growth and flowering.
- Taxon
- ArabidopsisArabidopsist0
- Gene
- GAMYB-like genese0
- Outcome
- growth and flowering responsese0
- Qualifier
- may mediate GA signalinge0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“GAMYB-like genes may mediate GA signaling in growth and flowering responses”
t0“Arabidopsis”
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See all 80 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.