TY - JOUR
T1 - Mitogen-activated protein kinase is involved in abscisic acid-induced antioxidant defense and acts downstream of reactive oxygen species production in leaves of maize plants
AU - Zhang, Aying
AU - Jiang, Mingyi
AU - Zhang, Jianhua
AU - Tan, Mingpu
AU - Hu, Xiuli
N1 - This work was supported by the Major State Basic Research Program of China (grant no. 2003CB114302 to M.J.), the National Natural Science Foundation of China (grant no. 30471048 to M.J.), the Key Project of Chinese Ministry of Education (grant no. 104100 to M.J.), the Science Foundation of Doctoral Subject Point of Chinese Ministry of Education (grant no. 20040307011 to M.J.), and the Hong Kong Research Grants Council (HKBU 2149/04M to J.Z.).
PY - 2006/6
Y1 - 2006/6
N2 - The role of mitogen-activated protein kinase (MAPK) in abscisic acid (ABA)-induced antioxidant defense was investigated in leaves of maize (Zea mays) plants. Treatments with ABA or H2O2 induced the activation of a 46-kD MAPK and enhanced the expression of the antioxidant genes CAT1, cAPX, and GR1 and the total activities of the antioxidant enzymes catalase, ascorbate peroxidase, glutathione reductase, and superoxide dismutase. Such enhancements were blocked by pretreatment with several MAPK kinase inhibitors and reactive oxygen species inhibitors or scavengers. Pretreatment with MAPK kinase inhibitors also substantially arrested the ABA-induced H 2O2 production after 2 h of ABA treatment, but did not affect the levels of H2O2 within 1 h of ABA treatment. Pretreatment with several inhibitors of protein tyrosine phosphatase, which is believed to be a negative regulator of MAPK, only slightly prevented the ABA-induced H2O2 production, but did not affect the ABA-induced MAPK activation and ABA-enhanced antioxidant defense systems. These results clearly suggest that MAPK but not protein tyrosine phosphatase is involved in the ABA-induced antioxidant defense, and a cross talk between H 2O2 production and MAPK activation plays a pivotal role in the ABA signaling. ABA-induced H2O2 production activates MAPK, which in turn induces the expression and the activities of antioxidant enzymes. The activation of MAPK also enhances the H2O2 production, forming a positive feedback loop.
AB - The role of mitogen-activated protein kinase (MAPK) in abscisic acid (ABA)-induced antioxidant defense was investigated in leaves of maize (Zea mays) plants. Treatments with ABA or H2O2 induced the activation of a 46-kD MAPK and enhanced the expression of the antioxidant genes CAT1, cAPX, and GR1 and the total activities of the antioxidant enzymes catalase, ascorbate peroxidase, glutathione reductase, and superoxide dismutase. Such enhancements were blocked by pretreatment with several MAPK kinase inhibitors and reactive oxygen species inhibitors or scavengers. Pretreatment with MAPK kinase inhibitors also substantially arrested the ABA-induced H 2O2 production after 2 h of ABA treatment, but did not affect the levels of H2O2 within 1 h of ABA treatment. Pretreatment with several inhibitors of protein tyrosine phosphatase, which is believed to be a negative regulator of MAPK, only slightly prevented the ABA-induced H2O2 production, but did not affect the ABA-induced MAPK activation and ABA-enhanced antioxidant defense systems. These results clearly suggest that MAPK but not protein tyrosine phosphatase is involved in the ABA-induced antioxidant defense, and a cross talk between H 2O2 production and MAPK activation plays a pivotal role in the ABA signaling. ABA-induced H2O2 production activates MAPK, which in turn induces the expression and the activities of antioxidant enzymes. The activation of MAPK also enhances the H2O2 production, forming a positive feedback loop.
UR - http://www.scopus.com/inward/record.url?scp=33745677488&partnerID=8YFLogxK
U2 - 10.1104/pp.105.075416
DO - 10.1104/pp.105.075416
M3 - Journal article
C2 - 16531486
AN - SCOPUS:33745677488
SN - 0032-0889
VL - 141
SP - 475
EP - 487
JO - Plant Physiology
JF - Plant Physiology
IS - 2
ER -