Nitric oxide acts as an antioxidant and delays programmed cell death in barley aleurone layers
Nitric oxide acts as an antioxidant and delays programmed cell death in barley aleurone layers
复制标题
DOI：
10.1104/pp.002337
复制
发表时间：
2002-08-01
期刊：
影响因子：
7.4
通讯作者：
Jones, RL
中科院分区：
文献类型：
--
作者：
Beligni, MV;Fath, A;Jones, RL
一氧化氮（NO）是一种可自由扩散的气态自由基，是动物体内重要的信号分子。在植物中，NO影响生长和发育的各个方面，并且可以影响植物对胁迫的反应。在某些情况下，NO的作用是其与活性氧（ROS）相互作用的结果。这些相互作用可以是细胞毒性的或保护性的。由于赤霉素（GA）诱导的程序性细胞死亡（PCD）在大麦（大麦品种喜马拉雅）糊粉层是由ROS介导的，我们研究了在这个系统中的PCD和ROS代谢酶的NO供体的影响。NO供体延迟GA处理的蛋鸡PCD，但一般不抑制代谢，或GA诱导的α-淀粉酶的合成和分泌。α-淀粉酶分泌被NO供体轻微刺激。NO供体的作用是NO特异性的，因为它们可以被NO清除剂2-（4-羧基苯基）-4，4，5，5-四甲基咪唑啉-1-氧基-3-氧化物完全阻断。抗氧化剂丁基化羟基甲苯也减缓PCD，这些数据支持我们的假设，即NO是糊粉细胞中的保护性抗氧化剂。GA处理的糊粉层中两种活性氧代谢酶CAT和SOD的含量显著降低。在NO供体存在下用GA处理延迟了CAT和SOD的损失。我们推测NO可能是大麦糊粉层细胞PCD的内源性调节因子。
Nitric oxide (NO) is a freely diffusible, gaseous free radical and an important signaling molecule in animals. In plants, NO influences aspects of growth and development, and can affect plant responses to stress. In some cases, the effects of NO are the result of its interaction with reactive oxygen species (ROS). These interactions can be cytotoxic or protective. Because gibberellin (GA)-induced programmed cell death (PCD) in barley (Hordeum vulgare cv Himalaya) aleurone layers is mediated by ROS, we examined the effects of NO donors on PCD and ROS-metabolizing enzymes in this system. NO donors delay PCD in layers treated with GA, but do not inhibit metabolism in general, or the GA-induced synthesis and secretion of a-amylase. a-Amylase secretion is stimulated slightly by NO donors. The effects of NO donors are specific for NO, because they can be blocked completely by the NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetrarnethylimidazoline-1-oxyl-3-oxide. The antioxidant butylated hydroxy toluene also slowed PCD, and these data support our hypothesis that NO is a protective antioxidant in aleurone cells. The amounts of CAT and SOD, two enzymes that metabolize ROS, are greatly reduced in aleurone layers treated with GA. Treatment with GA in the presence of NO donors delays the loss of CAT and SOD. We speculate that NO may be an endogenous modulator of PCD in barley aleurone cells.