Abstract
Paddy fields are anaerobic and facilitate arsenite (As(III)) elution from the soil. Paddy-field rice accumulates arsenic (As) in its grains because silicate transporters actively assimilate As(III) during the reproductive stage. Reducing the As level in rice grains is an important challenge for agriculture. Using a forward genetic approach, we isolated a rice (Oryza sativa) mutant, low arsenic line 3 (las3), whose As levels were decreased in aerial tissues, including grains. The low-As phenotype was not observed in young plants before heading (emergence of the panicle). Genetic analyses revealed that a deficiency in alcohol dehydrogenase (ADH) 2 by mutation is responsible for the phenotype. Among the three rice ADH paralogues, ADH2 was the most efficiently produced in root tissue under anaerobic conditions. In wild-type (WT), silicon and As concentrations in aerial tissues increased with growth. However, the increase was suppressed in las3 during the reproductive stage. Accordingly, the gene expression of two silicate transporters, Lsi1 and Lsi2, was increased in WT around the time of heading, whereas the increase was suppressed in las3. These results indicate that the low-As phenotype in las3 is due to silicate transporter suppression. Measurement of intracellular pH by 31P-nuclear magnetic resonance revealed intracellular acidification of las3 roots under hypoxia, suggesting that silicate transporter suppression in las3 might arise from an intracellular pH decrease, which is known to be facilitated by a deficiency in ADH activity under anaerobic conditions. This study provides valuable insight into reducing As levels in rice grains.
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 11
Claim · model-written summary
The las3 mutant had decreased arsenic levels in aerial tissues, including grains, compared with wild type.
- Taxon
- rice (Oryza sativa)
Oryza sativae1 - Material
- low arsenic line 3 (las3)e1
- Organ / stage
- aerial tissuese1
- Outcome
- As levelse1
- Direction
- decreasede1
- Comparator
- wild-type (WT)e2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“we isolated a rice (Oryza sativa) mutant, low arsenic line 3 (las3), whose As levels were decreased in aerial tissues, including grains”
e2“In wild-type (WT)”
Claim · model-written summary
The low-arsenic phenotype of las3 was not observed in young plants before heading.
- Taxon
- rice (Oryza sativa)Oryza sativae1
- Organ / stage
- young plants before headinge3
- Outcome
- low-As phenotypee3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“we isolated a rice (Oryza sativa) mutant, low arsenic line 3 (las3), whose As levels were decreased in aerial tissues, including grains”
e3“The low-As phenotype was not observed in young plants before heading”
Claim · model-written summary
A deficiency in alcohol dehydrogenase (ADH) 2 caused by mutation is responsible for the low-arsenic phenotype of las3.
- Taxon
- rice (Oryza sativa)Oryza sativae1
- Gene
- alcohol dehydrogenase (ADH) 2e4
- Outcome
- phenotypee4
- Qualifier
- by mutatione4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“we isolated a rice (Oryza sativa) mutant, low arsenic line 3 (las3), whose As levels were decreased in aerial tissues, including grains”
e4“Genetic analyses revealed that a deficiency in alcohol dehydrogenase (ADH) 2 by mutation is responsible for the phenotype”
Claim · model-written summary
Among three rice ADH paralogues, ADH2 was produced most efficiently in root tissue under anaerobic conditions.
- Taxon
- riceOryza sativae5
- Organ / stage
- root tissuee5
- Treatment
- anaerobic conditionse5
- Gene
- ADH2e5
- Outcome
- producede5
- Direction
- most efficientlye5
- Comparator
- the three rice ADH paraloguese5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e5“Among the three rice ADH paralogues, ADH2 was the most efficiently produced in root tissue under anaerobic conditions”
Claim · model-written summary
In wild-type rice, silicon and arsenic concentrations in aerial tissues increased with growth.
- Taxon
- rice (Oryza sativa)Oryza sativae1
- Material
- wild-type (WT)e6
- Organ / stage
- aerial tissuese6
- Outcome
- silicon and As concentrationse6
- Direction
- increasede6
- Qualifier
- with growthe6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“we isolated a rice (Oryza sativa) mutant, low arsenic line 3 (las3), whose As levels were decreased in aerial tissues, including grains”
e6“In wild-type (WT), silicon and As concentrations in aerial tissues increased with growth”
Claim · model-written summary
In las3, the increase in silicon and arsenic concentrations was suppressed during the reproductive stage relative to wild type.
- Taxon
- rice (Oryza sativa)Oryza sativae1
- Material
- las3e7
- Organ / stage
- reproductive stagee7
- Outcome
- the increasee7
- Direction
- suppressede7
- Comparator
- wild-type (WT)e6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“we isolated a rice (Oryza sativa) mutant, low arsenic line 3 (las3), whose As levels were decreased in aerial tissues, including grains”
e6“In wild-type (WT), silicon and As concentrations in aerial tissues increased with growth”
e7“However, the increase was suppressed in las3 during the reproductive stage”
Claim · model-written summary
Gene expression of the silicate transporters Lsi1 and Lsi2 increased in wild-type rice around the time of heading.
- Taxon
- rice (Oryza sativa)Oryza sativae1
- Material
- WTe2
- Organ / stage
- around the time of headinge2
- Gene
- Lsi1 and Lsi2e2
- Outcome
- gene expressione2
- Direction
- increasede2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“we isolated a rice (Oryza sativa) mutant, low arsenic line 3 (las3), whose As levels were decreased in aerial tissues, including grains”
e2“Accordingly, the gene expression of two silicate transporters, Lsi1 and Lsi2, was increased in WT around the time of heading”
Claim · model-written summary
The increase in Lsi1 and Lsi2 gene expression around heading was suppressed in las3 relative to wild type.
- Taxon
- rice (Oryza sativa)Oryza sativae1
- Material
- las3e3
- Organ / stage
- around the time of headinge2
- Gene
- Lsi1 and Lsi2e2
- Outcome
- the increasee3
- Direction
- suppressede3
- Comparator
- WTe2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“we isolated a rice (Oryza sativa) mutant, low arsenic line 3 (las3), whose As levels were decreased in aerial tissues, including grains”
e2“Accordingly, the gene expression of two silicate transporters, Lsi1 and Lsi2, was increased in WT around the time of heading”
e3“whereas the increase was suppressed in las3”
Claim · model-written summary
The low-arsenic phenotype of las3 is attributed to suppression of silicate transporters.
- Taxon
- rice (Oryza sativa)Oryza sativae1
- Material
- las3e4
- Gene
- silicate transportere4
- Outcome
- low-As phenotypee4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“we isolated a rice (Oryza sativa) mutant, low arsenic line 3 (las3), whose As levels were decreased in aerial tissues, including grains”
e4“These results indicate that the low-As phenotype in las3 is due to silicate transporter suppression”
Claim · model-written summary
Intracellular acidification was measured in las3 roots under hypoxia by 31P-NMR.
- Taxon
- rice (Oryza sativa)Oryza sativae1
- Material
- las3e5
- Organ / stage
- rootse5
- Treatment
- hypoxiae5
- Outcome
- intracellular acidificatione5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“we isolated a rice (Oryza sativa) mutant, low arsenic line 3 (las3), whose As levels were decreased in aerial tissues, including grains”
e5“Measurement of intracellular pH by 31P-nuclear magnetic resonance revealed intracellular acidification of las3 roots under hypoxia”
Claim · model-written summary
Silicate transporter suppression in las3 might arise from an intracellular pH decrease.
- Taxon
- rice (Oryza sativa)Oryza sativae1
- Material
- las3e5
- Outcome
- silicate transporter suppressione5
- Qualifier
- intracellular pH decreasee5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e1“we isolated a rice (Oryza sativa) mutant, low arsenic line 3 (las3), whose As levels were decreased in aerial tissues, including grains”
e5“suggesting that silicate transporter suppression in las3 might arise from an intracellular pH decrease”