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Gene knockout study reveals that cytosolic ascorbate peroxidase 2(OsAPX2) plays a critical role in growth and reproduction in rice under drought, salt and cold stresses.

Zhang Z, Zhang Q, Wu J, Zheng X, Zheng S, Sun X, Qiu Q, Lu T - PLoS ONE (2013)

Bottom Line: Loss of function in OsAPX2 affected the growth and development of rice seedlings, resulting in semi-dwarf seedlings, yellow-green leaves, leaf lesion mimic and seed sterility.H2O2 and MDA levels were high in Osapx2 mutants but low in OsAPX2-OX transgenic lines relative to wild-type plants after stress treatments.Taken together, the cytosolic ascorbate peroxidase OsAPX2 plays an important role in rice growth and development by protecting the seedlings from abiotic stresses through scavenging reactive oxygen species.

View Article: PubMed Central - PubMed

Affiliation: Biotechnology Research Institute, Chinese Academy of Agricultural Sciences/National Key facility for Gene Resources And Genetic Improvement, Beijing, China.

ABSTRACT
Plant ascorbate peroxidases (APXs), enzymes catalyzing the dismutation of H2O2 into H2O and O2, play an important role in reactive oxygen species homeostasis in plants. The rice genome has eight OsAPXs, but their physiological functions remain to be determined. In this report, we studied the function of OsAPX2 gene using a T-DNA knockout mutant under the treatment of drought, salt and cold stresses. The Osapx2 knockout mutant was isolated by a genetic screening of a rice T-DNA insertion library under 20% PEG-2000 treatment. Loss of function in OsAPX2 affected the growth and development of rice seedlings, resulting in semi-dwarf seedlings, yellow-green leaves, leaf lesion mimic and seed sterility. OsAPX2 expression was developmental- and spatial-regulated, and was induced by drought, salt, and cold stresses. Osapx2 mutants had lower APX activity and were sensitive to abiotic stresses; overexpression of OsAPX2 increased APX activity and enhanced stress tolerance. H2O2 and MDA levels were high in Osapx2 mutants but low in OsAPX2-OX transgenic lines relative to wild-type plants after stress treatments. Taken together, the cytosolic ascorbate peroxidase OsAPX2 plays an important role in rice growth and development by protecting the seedlings from abiotic stresses through scavenging reactive oxygen species.

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Related in: MedlinePlus

H2O2 content assay of wild-type, Osapx2, complementation and OsAPX2-OX plants at different developmental stages.H2O2 content assay was performed in wild-type, Osapx2, independent complementation lines (cp1 and cp2) and independent OsAPX2-OX lines (OX1 and OX2) at different developmental stages. Different letters (a–c) indicate significant differences (P<0.05) between lines.
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pone-0057472-g014: H2O2 content assay of wild-type, Osapx2, complementation and OsAPX2-OX plants at different developmental stages.H2O2 content assay was performed in wild-type, Osapx2, independent complementation lines (cp1 and cp2) and independent OsAPX2-OX lines (OX1 and OX2) at different developmental stages. Different letters (a–c) indicate significant differences (P<0.05) between lines.

Mentions: H2O2 content was analyzed in wild-type, Osapx2, complementation lines and OsAPX2-OX lines at different developmental stages. As shown in Figure 14, for all of the lines, the H2O2 level was lower in seedlings, but increased gradually with the growth and reached a high level in spikelets. However, H2O2 level of Osapx2 mutant plants was significantly higher than that of wild-type in all growing stage. H2O2 content of complementation lines was similar to that of wild-type plants at seedling stage, while it is still higher than that of wild-type plants at tillering stage and in spikelet. By contrast, the accumulation of H2O2 in OsAPX2-OX transgenic lines was lower than the wild-type plants.


Gene knockout study reveals that cytosolic ascorbate peroxidase 2(OsAPX2) plays a critical role in growth and reproduction in rice under drought, salt and cold stresses.

Zhang Z, Zhang Q, Wu J, Zheng X, Zheng S, Sun X, Qiu Q, Lu T - PLoS ONE (2013)

H2O2 content assay of wild-type, Osapx2, complementation and OsAPX2-OX plants at different developmental stages.H2O2 content assay was performed in wild-type, Osapx2, independent complementation lines (cp1 and cp2) and independent OsAPX2-OX lines (OX1 and OX2) at different developmental stages. Different letters (a–c) indicate significant differences (P<0.05) between lines.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3585366&req=5

pone-0057472-g014: H2O2 content assay of wild-type, Osapx2, complementation and OsAPX2-OX plants at different developmental stages.H2O2 content assay was performed in wild-type, Osapx2, independent complementation lines (cp1 and cp2) and independent OsAPX2-OX lines (OX1 and OX2) at different developmental stages. Different letters (a–c) indicate significant differences (P<0.05) between lines.
Mentions: H2O2 content was analyzed in wild-type, Osapx2, complementation lines and OsAPX2-OX lines at different developmental stages. As shown in Figure 14, for all of the lines, the H2O2 level was lower in seedlings, but increased gradually with the growth and reached a high level in spikelets. However, H2O2 level of Osapx2 mutant plants was significantly higher than that of wild-type in all growing stage. H2O2 content of complementation lines was similar to that of wild-type plants at seedling stage, while it is still higher than that of wild-type plants at tillering stage and in spikelet. By contrast, the accumulation of H2O2 in OsAPX2-OX transgenic lines was lower than the wild-type plants.

Bottom Line: Loss of function in OsAPX2 affected the growth and development of rice seedlings, resulting in semi-dwarf seedlings, yellow-green leaves, leaf lesion mimic and seed sterility.H2O2 and MDA levels were high in Osapx2 mutants but low in OsAPX2-OX transgenic lines relative to wild-type plants after stress treatments.Taken together, the cytosolic ascorbate peroxidase OsAPX2 plays an important role in rice growth and development by protecting the seedlings from abiotic stresses through scavenging reactive oxygen species.

View Article: PubMed Central - PubMed

Affiliation: Biotechnology Research Institute, Chinese Academy of Agricultural Sciences/National Key facility for Gene Resources And Genetic Improvement, Beijing, China.

ABSTRACT
Plant ascorbate peroxidases (APXs), enzymes catalyzing the dismutation of H2O2 into H2O and O2, play an important role in reactive oxygen species homeostasis in plants. The rice genome has eight OsAPXs, but their physiological functions remain to be determined. In this report, we studied the function of OsAPX2 gene using a T-DNA knockout mutant under the treatment of drought, salt and cold stresses. The Osapx2 knockout mutant was isolated by a genetic screening of a rice T-DNA insertion library under 20% PEG-2000 treatment. Loss of function in OsAPX2 affected the growth and development of rice seedlings, resulting in semi-dwarf seedlings, yellow-green leaves, leaf lesion mimic and seed sterility. OsAPX2 expression was developmental- and spatial-regulated, and was induced by drought, salt, and cold stresses. Osapx2 mutants had lower APX activity and were sensitive to abiotic stresses; overexpression of OsAPX2 increased APX activity and enhanced stress tolerance. H2O2 and MDA levels were high in Osapx2 mutants but low in OsAPX2-OX transgenic lines relative to wild-type plants after stress treatments. Taken together, the cytosolic ascorbate peroxidase OsAPX2 plays an important role in rice growth and development by protecting the seedlings from abiotic stresses through scavenging reactive oxygen species.

Show MeSH
Related in: MedlinePlus