NADPH氧化酶可能参与了ABA诱导蚕豆气孔保卫细胞运动

The NADPH Oxidase Is Likely Involved in ABA-Induced Stomatal Guard Cell Movement in Vicia faba

研究了 NADPH氧化酶在 ABA( abscisic acid)诱导蚕豆气孔关闭信号转导网络中的作用 ,荧光光谱实验表明 ,在嗜中性白血球 NADPH氧化酶抑制剂 DPI( diphenyleneio-donium)存在的条件下 ,与对照相比 ,大大逆转了由 ABA引起 HPTS( 8- hydroxypyrene- 1 ,3,6- trisulfonic acid,trisodium salt)的荧光强度下降。表皮生物分析法显示 ,1 0 - 6mol/ L的 DPI和 1 0 3unit/ m L的过氧化氢酶 ( catalase,CAT)在一定程度上也逆转了 ABA诱导张开气孔的关闭。因此推测 :在 ABA诱导蚕豆气孔保卫细胞过程中 ,质膜上的 NADPH氧化酶可能催化形成超氧自由基 O2 ,再经歧化反应形成 H2 O2 ,而形成的 H2 O2

The mechanisms of H 2O 2 generation in guard cells of Vicia faba induced by abscisic acid (ABA) were measured by using fluorescene probe, 8 hydroxypyrene 1 ,3,6 trisulfonic acid, trisodium salt (HPTS). When guard cells were treated with ABA, fluorescene quenching of HPTS occurred, and the treatment of the guard cells with diphenyleneiodonium(DPI) at 10 -6 mol/mL (final concentration) which is known as an inhibitor of supero xide generating NADPH oxidases nearly reversed the quenching reaction induced by ABA 0 2 mmol/L(final concentration). ABA and H 2O 2 might induce stomatal closure. Furthermore, when DPI or catalase(CAT)( 10 3 unit/mL ) was added to the suspension after above treatment reversed ABA induced stomatal closure. These results suggest that a novel O 2  generating NADPH oxidase in the plasma membrane of guard cell of Vicia faba may be activated by ABA, and subsequently H 2O 2, which involved in the signal transduction pathway of ABA induced stomatal closure.