Limits...
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.

Show MeSH

Related in: MedlinePlus

APX activity assay of wild-type, Osapx2 and OsAPX2-OX plants.Five leaf seedlings grown in the half-strengthened MS liquid medium were treated with different treatments. For salt treatment, wild-type, Osapx2 and OsAPX2-OX plants were treated with 150 mM NaCl for 24 h; for cold treatment, plants were transferred to a 10°C incubator for 24 h; for drought treatment, plants were transferred to dry sterile petri dishes or 2 h. Different letters (a–c) indicate significant differences (P<0.05) between lines.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3585366&req=5

pone-0057472-g013: APX activity assay of wild-type, Osapx2 and OsAPX2-OX plants.Five leaf seedlings grown in the half-strengthened MS liquid medium were treated with different treatments. For salt treatment, wild-type, Osapx2 and OsAPX2-OX plants were treated with 150 mM NaCl for 24 h; for cold treatment, plants were transferred to a 10°C incubator for 24 h; for drought treatment, plants were transferred to dry sterile petri dishes or 2 h. Different letters (a–c) indicate significant differences (P<0.05) between lines.

Mentions: In order to understand whether or not APX2 is important in scavenging H2O2 in rice, we analyzed the APX activity and H2O2 contents in wild-type, Osapx2 and OsAPX2-OX plants. As shown in Figure 13, APX activity in Osapx2 was lower than that of wild-type plants under both normal and stress conditions; by contrast, OsAPX2-OX transgenic lines showed higher levels of APX activity under both normal and stress conditions compared to 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)

APX activity assay of wild-type, Osapx2 and OsAPX2-OX plants.Five leaf seedlings grown in the half-strengthened MS liquid medium were treated with different treatments. For salt treatment, wild-type, Osapx2 and OsAPX2-OX plants were treated with 150 mM NaCl for 24 h; for cold treatment, plants were transferred to a 10°C incubator for 24 h; for drought treatment, plants were transferred to dry sterile petri dishes or 2 h. 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-g013: APX activity assay of wild-type, Osapx2 and OsAPX2-OX plants.Five leaf seedlings grown in the half-strengthened MS liquid medium were treated with different treatments. For salt treatment, wild-type, Osapx2 and OsAPX2-OX plants were treated with 150 mM NaCl for 24 h; for cold treatment, plants were transferred to a 10°C incubator for 24 h; for drought treatment, plants were transferred to dry sterile petri dishes or 2 h. Different letters (a–c) indicate significant differences (P<0.05) between lines.
Mentions: In order to understand whether or not APX2 is important in scavenging H2O2 in rice, we analyzed the APX activity and H2O2 contents in wild-type, Osapx2 and OsAPX2-OX plants. As shown in Figure 13, APX activity in Osapx2 was lower than that of wild-type plants under both normal and stress conditions; by contrast, OsAPX2-OX transgenic lines showed higher levels of APX activity under both normal and stress conditions compared to 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