Xue Beibei, Zhang Aying, Jiang Mingyi
College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China.
J Integr Plant Biol. 2009 Mar;51(3):225-34. doi: 10.1111/j.1744-7909.2008.00766.x.
Using pharmacological and biochemical approaches, the role of maize polyamine oxidase (MPAO) in abscisic acid (ABA)-induced antioxidant defense in leaves of maize (Zea mays L.) plants was investigated. Exogenous ABA treatment enhanced the expression of the MPAO gene and the activities of apoplastic MPAO. Pretreatment with two different inhibitors for apoplastic MPAO partly reduced hydrogen peroxide (H2O2) accumulation induced by ABA and blocked the ABA-induced expression of the antioxidant genes superoxide dismutase 4 and cytosolic ascorbate peroxidase and the activities of the cytosolic antioxidant enzymes. Treatment with spermidine, the optimum substrate of MPAO, also induced the expression and the activities of the antioxidant enzymes, and the upregulation of the antioxidant enzymes was prevented by two inhibitors of MPAO and two scavengers of H2O2. These results suggest that MPAO contributes to ABA-induced cytosolic antioxidant defense through H2O2, a Spd catabolic product.
利用药理学和生物化学方法，研究了玉米多胺氧化酶（MPAO）在脱落酸（ABA）诱导的玉米（Zea mays L.）植株叶片抗氧化防御中的作用。外源ABA处理增强了MPAO基因的表达和质外体MPAO的活性。用两种不同的质外体MPAO抑制剂预处理可部分降低ABA诱导的过氧化氢（H2O2）积累，并阻断ABA诱导的抗氧化基因超氧化物歧化酶4和胞质抗坏血酸过氧化物酶的表达以及胞质抗氧化酶的活性。用MPAO的最佳底物亚精胺处理也诱导了抗氧化酶的表达和活性，而MPAO的两种抑制剂和两种H2O2清除剂可阻止抗氧化酶的上调。这些结果表明，MPAO通过H2O2（一种亚精胺分解产物）促进ABA诱导的胞质抗氧化防御。
