Abstract
Flavonoid compounds such as anthocyanins and proanthocyanidins (PAs; so-called condensed tannins) have a multitude of functions in plants. They must be transported from the site of synthesis in the cytosol to their final destination, the vacuoles. Three models have been proposed for sequestering anthocyanins in vacuoles, but the transport machinery for PAs is poorly understood. Novel Arabidopsis mutants, transparent testa 19 (tt19), which were induced by ion beam irradiation, showed a great reduction of anthocyanin pigments in the vegetative parts as well as brown pigments in the seed coat. The TT19 gene was isolated by chromosome walking and a candidate gene approach, and was shown to be a member of the Arabidopsis glutathione S-transferase (GST) gene family. Heterologous expression of a putative ortholog, petunia anthocyanin 9 (AN9), in tt19 complemented the anthocyanin accumulation but not the brown pigmentation in the seed coat. This suggests that the TT19 gene is required for vacuolar uptake of anthocyanins into vacuoles, but that it has also a function different from that of AN9. The depositional pattern of PA precursors in the mutant was different from that in the wild type. These results indicate that TT19 participates in the PA pathway as well as the anthocyanin pathway of Arabidopsis. As involvement of GST in the PA pathway was previously considered unlikely, the function of TT19 in the PA pathway is also discussed in the context of the putative transporter for PA precursors.
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Claims 8
Claim · model-written summary
tt19 mutants had greatly reduced anthocyanin pigments in vegetative parts.
- Taxon
- Arabidopsis
Arabidopsise0 - Material
- transparent testa 19 (tt19)e0
- Organ / stage
- vegetative partse0
- Outcome
- anthocyanin pigmentse0
- Direction
- reductione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Novel Arabidopsis mutants, transparent testa 19 (tt19), which were induced by ion beam irradiation, showed a great reduction of anthocyanin pigments in the vegetative parts as well as brown pigments in the seed coat.”
Claim · model-written summary
tt19 mutants had greatly reduced brown seed-coat pigments.
- Taxon
- ArabidopsisArabidopsise0
- Material
- transparent testa 19 (tt19)e0
- Organ / stage
- seed coate0
- Outcome
- brown pigmentse0
- Direction
- reductione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Novel Arabidopsis mutants, transparent testa 19 (tt19), which were induced by ion beam irradiation, showed a great reduction of anthocyanin pigments in the vegetative parts as well as brown pigments in the seed coat.”
Claim · model-written summary
TT19 was isolated and identified as a member of the Arabidopsis GST gene family.
- Taxon
- ArabidopsisArabidopsise0
- Gene
- TT19e0
- Outcome
- member of the Arabidopsis glutathione S-transferase (GST) gene familye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The TT19 gene was isolated by chromosome walking and a candidate gene approach, and was shown to be a member of the Arabidopsis glutathione S-transferase (GST) gene family.”
Claim · model-written summary
Petunia AN9 expression complemented anthocyanin accumulation in tt19.
- Taxon
- ArabidopsisArabidopsist0
- Material
- tt19e0
- Treatment
- Heterologous expressione0
- Gene
- petunia anthocyanin 9 (AN9)e0
- Outcome
- anthocyanin accumulatione0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Heterologous expression of a putative ortholog, petunia anthocyanin 9 (AN9), in tt19 complemented the anthocyanin accumulation but not the brown pigmentation in the seed coat.”
t0“Arabidopsis”
Claim · model-written summary
Petunia AN9 expression did not complement brown seed-coat pigmentation in tt19.
- Taxon
- ArabidopsisArabidopsist0
- Material
- tt19e0
- Treatment
- Heterologous expressione0
- Gene
- petunia anthocyanin 9 (AN9)e0
- Outcome
- brown pigmentatione0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Heterologous expression of a putative ortholog, petunia anthocyanin 9 (AN9), in tt19 complemented the anthocyanin accumulation but not the brown pigmentation in the seed coat.”
t0“Arabidopsis”
Claim · model-written summary
The depositional pattern of PA precursors differed between tt19 and wild type.
- Taxon
- ArabidopsisArabidopsist0
- Material
- mutante0
- Outcome
- depositional pattern of PA precursorse0
- Comparator
- wild typee0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The depositional pattern of PA precursors in the mutant was different from that in the wild type.”
t0“Arabidopsis”
Claim · model-written summary
The authors infer that TT19 is required for vacuolar uptake of anthocyanins.
- Taxon
- ArabidopsisArabidopsist0
- Gene
- TT19e0
- Outcome
- vacuolar uptake of anthocyaninse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“This suggests that the TT19 gene is required for vacuolar uptake of anthocyanins into vacuoles”
t0“Arabidopsis”
Claim · model-written summary
The authors infer that TT19 participates in the PA pathway and anthocyanin pathway.
- Taxon
- ArabidopsisArabidopsise0
- Gene
- TT19e0
- Outcome
- PA pathway as well as the anthocyanin pathwaye0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“These results indicate that TT19 participates in the PA pathway as well as the anthocyanin pathway of Arabidopsis.”
The same questions in other papers
overexpression · quality: phytochemicals · ArabidopsisPositive and negative results
7 papers in the same direction as this paper · 2 in the opposite direction
- negative
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6 papers more in this group
See all 10 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.