Abstract
This work demonstrated how reactive oxygen species (ROS) are involved in the regulation of rhizogenesis from hypocotyls of Mesembryanthemum crystallinum L. cultured on a medium containing 1-naphthaleneacetic acid (NAA). The increase of NADPH oxidase activity was correlated with an increase of hydrogen peroxide (H2O2) content and induction of mitotic activity in vascular cylinder cells, leading to root formation from cultured hypocotyls. Diphenylene iodonium (DPI), an inhibitor of NADPH oxidase, inhibited H2O2 production and blocked rhizogenesis. Ultrastructural studies revealed differences in H2O2 localization between the vascular cylinder cells and cortex parenchyma cells of cultured explants. We suggest that NADPH oxidase is responsible for H2O2 level regulation in vascular cylinder cells, while peroxidase (POD) participates in H2O2 level regulation in cortex cells. Blue formazan (NBT) precipitates indicating superoxide radical (O2 (•-)) accumulation were localized within the vascular cylinder cells during the early stages of rhizogenesis and at the tip of root primordia, as well as in the distal and middle parts of newly formed organs. 3,3'-diaminobenzidine (DAB) staining of H2O2 was more intense in vascular bundle cells and in cortex cells. In newly formed roots, H2O2 was localized in vascular tissue. Adding DPI to the medium led to a decrease in the intensity of NBT and DAB staining in cultured explants. Accumulation of O2 (•-) was then limited to epidermis cells, while H2O2 was accumulated only in vascular tissue. These results indicate that O2 (•-) is engaged in processes of rhizogenesis induction involving division of competent cells, while H2O2 is engaged in developmental processes mainly involving cell growth.
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Claims 14
Claim · model-written summary
Reactive oxygen species are involved in regulating rhizogenesis from hypocotyls of Mesembryanthemum crystallinum cultured on medium with NAA.
- Taxon
- Mesembryanthemum crystallinum L.
Mesembryanthemum crystallinumt0 - Organ / stage
- hypocotylse0
- Treatment
- 1-naphthaleneacetic acid (NAA)e0
- Compound
- reactive oxygen species (ROS)e0
- Outcome
- regulation of rhizogenesise0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Mesembryanthemum crystallinum L.”
e0“reactive oxygen species (ROS) are involved in the regulation of rhizogenesis from hypocotyls of Mesembryanthemum crystallinum L. cultured on a medium containing 1-naphthaleneacetic acid (NAA)”
Claim · model-written summary
Increased NADPH oxidase activity was correlated with increased hydrogen peroxide content and induction of mitotic activity in vascular cylinder cells of cultured hypocotyls.
- Taxon
- Mesembryanthemum crystallinum L.Mesembryanthemum crystallinumt0
- Organ / stage
- vascular cylinder cellse0
- Gene
- NADPH oxidasee0
- Outcome
- hydrogen peroxide (H2O2) content and induction of mitotic activitye0
- Direction
- increasee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Mesembryanthemum crystallinum L.”
e0“The increase of NADPH oxidase activity was correlated with an increase of hydrogen peroxide (H2O2) content and induction of mitotic activity in vascular cylinder cells”
Claim · model-written summary
DPI, an NADPH oxidase inhibitor, inhibited H2O2 production in cultured Mesembryanthemum crystallinum hypocotyls.
- Taxon
- Mesembryanthemum crystallinum L.Mesembryanthemum crystallinumt0
- Treatment
- Diphenylene iodonium (DPI)e0
- Outcome
- H2O2 productione0
- Direction
- inhibitede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Mesembryanthemum crystallinum L.”
e0“Diphenylene iodonium (DPI), an inhibitor of NADPH oxidase, inhibited H2O2 production and blocked rhizogenesis”
Claim · model-written summary
DPI, an NADPH oxidase inhibitor, blocked rhizogenesis in cultured Mesembryanthemum crystallinum hypocotyls.
- Taxon
- Mesembryanthemum crystallinum L.Mesembryanthemum crystallinumt0
- Treatment
- Diphenylene iodonium (DPI)e0
- Outcome
- rhizogenesise0
- Direction
- blockede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Mesembryanthemum crystallinum L.”
e0“Diphenylene iodonium (DPI), an inhibitor of NADPH oxidase, inhibited H2O2 production and blocked rhizogenesis”
Claim · model-written summary
Superoxide radical accumulation, shown by NBT precipitates, was localized within vascular cylinder cells in early rhizogenesis and at the tip of root primordia.
- Taxon
- Mesembryanthemum crystallinum L.Mesembryanthemum crystallinumt0
- Organ / stage
- vascular cylinder cellse0
- Outcome
- superoxide radical (O2 (•-)) accumulatione0
- Qualifier
- during the early stages of rhizogenesise0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Mesembryanthemum crystallinum L.”
e0“Blue formazan (NBT) precipitates indicating superoxide radical (O2 (•-)) accumulation were localized within the vascular cylinder cells during the early stages of rhizogenesis and at the tip of root primordia”
Claim · model-written summary
DAB staining of H2O2 was more intense in vascular bundle cells and in cortex cells.
- Taxon
- Mesembryanthemum crystallinum L.Mesembryanthemum crystallinumt0
- Organ / stage
- vascular bundle cells and in cortex cellse0
- Outcome
- staining of H2O2e0
- Direction
- more intensee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Mesembryanthemum crystallinum L.”
e0“3,3'-diaminobenzidine (DAB) staining of H2O2 was more intense in vascular bundle cells and in cortex cells”
Claim · model-written summary
In newly formed roots H2O2 was localized in vascular tissue.
- Taxon
- Mesembryanthemum crystallinum L.Mesembryanthemum crystallinumt0
- Organ / stage
- newly formed rootse0
- Outcome
- H2O2 was localized in vascular tissuee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Mesembryanthemum crystallinum L.”
e0“In newly formed roots, H2O2 was localized in vascular tissue”
Claim · model-written summary
Adding DPI to the medium decreased the intensity of NBT and DAB staining in cultured explants.
- Taxon
- Mesembryanthemum crystallinum L.Mesembryanthemum crystallinumt0
- Organ / stage
- cultured explantse0
- Treatment
- Adding DPI to the mediume0
- Outcome
- intensity of NBT and DAB staininge0
- Direction
- decreasee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Mesembryanthemum crystallinum L.”
e0“Adding DPI to the medium led to a decrease in the intensity of NBT and DAB staining in cultured explants”
Claim · model-written summary
With DPI in the medium, O2 accumulation was limited to epidermis cells.
- Taxon
- Mesembryanthemum crystallinum L.Mesembryanthemum crystallinumt0
- Organ / stage
- epidermis cellse0
- Outcome
- Accumulation of O2 (•-)e0
- Qualifier
- then limitede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Mesembryanthemum crystallinum L.”
e0“Accumulation of O2 (•-) was then limited to epidermis cells”
Claim · model-written summary
With DPI in the medium, H2O2 accumulated only in vascular tissue.
- Taxon
- Mesembryanthemum crystallinum L.Mesembryanthemum crystallinumt0
- Organ / stage
- vascular tissuee0
- Outcome
- H2O2 was accumulated only in vascular tissuee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Mesembryanthemum crystallinum L.”
e0“H2O2 was accumulated only in vascular tissue”
Claim · model-written summary
The authors suggest NADPH oxidase is responsible for regulating H2O2 level in vascular cylinder cells.
- Taxon
- Mesembryanthemum crystallinum L.Mesembryanthemum crystallinumt0
- Organ / stage
- vascular cylinder cellse0
- Gene
- NADPH oxidasee0
- Outcome
- H2O2 level regulatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Mesembryanthemum crystallinum L.”
e0“NADPH oxidase is responsible for H2O2 level regulation in vascular cylinder cells”
Claim · model-written summary
The authors suggest peroxidase participates in regulating H2O2 level in cortex cells.
- Taxon
- Mesembryanthemum crystallinum L.Mesembryanthemum crystallinumt0
- Organ / stage
- cortex cellse0
- Gene
- peroxidase (POD)e0
- Outcome
- H2O2 level regulatione0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Mesembryanthemum crystallinum L.”
e0“peroxidase (POD) participates in H2O2 level regulation in cortex cells”
Claim · model-written summary
The results indicate that O2 radical is engaged in rhizogenesis induction involving division of competent cells.
- Taxon
- Mesembryanthemum crystallinum L.Mesembryanthemum crystallinumt0
- Compound
- O2 (•-)e0
- Outcome
- rhizogenesis inductione0
- Qualifier
- division of competent cellse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Mesembryanthemum crystallinum L.”
e0“O2 (•-) is engaged in processes of rhizogenesis induction involving division of competent cells”
Claim · model-written summary
The results indicate that H2O2 is engaged in developmental processes mainly involving cell growth.
- Taxon
- Mesembryanthemum crystallinum L.Mesembryanthemum crystallinumt0
- Compound
- H2O2e0
- Outcome
- developmental processese0
- Qualifier
- mainly involving cell growthe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Mesembryanthemum crystallinum L.”
e0“H2O2 is engaged in developmental processes mainly involving cell growth”