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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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OsAPX2 expression response to drought, cold and salt stresses.A: OsAPX2 expression response to salt stress. B,C: Time course of OsAPX2 expression during drought and cold treatments. Actin was used as an internal control. Data represent means ± SD of three replicates.
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pone-0057472-g007: OsAPX2 expression response to drought, cold and salt stresses.A: OsAPX2 expression response to salt stress. B,C: Time course of OsAPX2 expression during drought and cold treatments. Actin was used as an internal control. Data represent means ± SD of three replicates.

Mentions: According to previous reports, the expression of APX genes is modulated by different environmental stimuli. To analyze the expression pattern of OsAPX2 in response to abiotic stresses, 2-week-old rice plants were subjected to drought, cold (4°C) and salt stresses, respectively. The accumulation of the transcripts was determined by RT-qPCR. As shown in Figure 7-A, OsAPX2 expression was induced by salt stress. After salt treatment for 1 h, transcript accumulation of OsAPX2 was increased by 4.5-fold under the treatment of 50 mM and 100 mM NaCl compared with the water mock control. Gene expression was increased by 7-fold after 150 mM NaCl treatment but was reduced to control level when treated with 250 mM NaCl. Also, OsAPX2 expression was induced by drought treatment. As shown in Figure 7-B, the expression of OsAPX2 reached peak at 1 h treatment but gradually reduced after 2 h treatment. Similarly, OsAPX2 expression was induced within 0.5 h after cold treatment and was highest after 1 h treatment (Figure 7-C).


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)

OsAPX2 expression response to drought, cold and salt stresses.A: OsAPX2 expression response to salt stress. B,C: Time course of OsAPX2 expression during drought and cold treatments. Actin was used as an internal control. Data represent means ± SD of three replicates.
© Copyright Policy
Related In: Results  -  Collection

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

pone-0057472-g007: OsAPX2 expression response to drought, cold and salt stresses.A: OsAPX2 expression response to salt stress. B,C: Time course of OsAPX2 expression during drought and cold treatments. Actin was used as an internal control. Data represent means ± SD of three replicates.
Mentions: According to previous reports, the expression of APX genes is modulated by different environmental stimuli. To analyze the expression pattern of OsAPX2 in response to abiotic stresses, 2-week-old rice plants were subjected to drought, cold (4°C) and salt stresses, respectively. The accumulation of the transcripts was determined by RT-qPCR. As shown in Figure 7-A, OsAPX2 expression was induced by salt stress. After salt treatment for 1 h, transcript accumulation of OsAPX2 was increased by 4.5-fold under the treatment of 50 mM and 100 mM NaCl compared with the water mock control. Gene expression was increased by 7-fold after 150 mM NaCl treatment but was reduced to control level when treated with 250 mM NaCl. Also, OsAPX2 expression was induced by drought treatment. As shown in Figure 7-B, the expression of OsAPX2 reached peak at 1 h treatment but gradually reduced after 2 h treatment. Similarly, OsAPX2 expression was induced within 0.5 h after cold treatment and was highest after 1 h treatment (Figure 7-C).

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