NADPH Oxidases Act as Key Enzyme on Germination and Seedling Growth in Barley (Hordeum vulgare L.)
NADPH Oxidases Act as Key Enzyme on Germination and Seedling Growth in Barley (Hordeum vulgare L.)
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DOI：
10.1626/pps.13.45
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发表时间：
2010-01-01
影响因子：
2.5
通讯作者：
Iwaya-Inoue, Mari
中科院分区：
文献类型：
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作者：
Ishibashi, Yushi;Tawaratsumida, Tomoya;Iwaya-Inoue, Mari
活性氧在种子萌发过程中起着重要作用。过氧化氢（H2 O2）是活性氧的一种，它能提高多种植物种子的发芽率，但其作用机制尚不清楚。NADPH氧化酶催化超氧阴离子（O-2）的产生，超氧阴离子（O-2）是ROS之一，并且酶调节植物发育。因此，我们研究了NADPH氧化酶在大麦种子萌发和幼苗生长中的作用。用蒸馏水（DW）处理大麦种子，在胚和糊粉层中均观察到O-2（-）的产生。而用NADPH氧化酶抑制剂氯化二苯碘鎓（DPI）处理的种子，则抑制了这一作用。此外，DPI显着延迟大麦种子萌发和显着抑制α-淀粉酶活性，表明NADPH氧化酶在大麦种子萌发的重要性。吸胀后，NADPH氧化酶基因表达量和酶活性逐渐增加，且酶活性与幼苗生长密切相关。此外，DPI对幼苗生长有明显的抑制作用。这些结果表明，NADPH氧化酶在大麦发芽和幼苗生长中起着至关重要的作用。这些事实清楚地表明，O-2（-）由NADPH氧化酶产生的吸胀后调节大麦种子萌发和幼苗生长。
Reactive oxygen species (ROS) play an important role in seed germination. Although hydrogen peroxide (H2O2), a type of ROS, enhances the germination rate of various plant seeds, little is known about the mechanism. NADPH oxidases catalyze the production of superoxide anion (O-2) that is one of the ROS and the enzymes regulate plant development. We, therefore, investigated the role of NADPH oxidases in seed germination and seedling growth in barley (Hondeum vulgare L.). The production of O-2(-) was observed both in embryo and aleurone layers in barley seeds treated with distilled water (DW). However, it was suppressed in seeds treated with diphenylene iodonium (DPI) chloride, NADPH oxidase inhibitor. Moreover, DPI markedly delayed germination and remarkably suppressed alpha-amylase activity in barley seeds, indicating the importance of NADPH oxidases in germination of barley seeds. The gene expression and the enzyme activity of NADPH oxidases gradually increased after imbibition, and the enzyme activities were closely correlated with seedling growth after imbibition. Besides, DPI markedly suppressed the seedling growth. These results indicated that NADPH oxidases perform a crucial function in germination and seedling growth in barley. These facts clearly reveal that O-2(-) produced by NADPH oxidases after imbibition regulates seed germination and seedling growth in barley.