Accumulation of salicylic acid and 4-hydroxybenzoic acid in phloem fluids of cucumber during systemic acquired resistance is preceded by a transient increase in phenylalanine ammonia-lyase activity in petioles and stems.
Accumulation of salicylic acid and 4-hydroxybenzoic acid in phloem fluids of cucumber during systemic acquired resistance is preceded by a transient increase in phenylalanine ammonia-lyase activity in petioles and stems.
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DOI：
10.1104/pp.116.1.231
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发表时间：
1998
期刊：
影响因子：
7.4
通讯作者：
J. Smith-Becker;E. Marois;E. Huguet;S. Midland;J. Sims;N. Keen
中科院分区：
文献类型：
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作者：
J. Smith-Becker;E. Marois;E. Huguet;S. Midland;J. Sims;N. Keen
黄瓜（Cucumis sativa）叶片被假单胞菌（Pseudomonaserichingae pv.）在接种后3 ~ 6 h，巨噬细胞产生一个移动的信号，用于系统获得抗性。接种叶片的移动的信号的生产，随后由苯丙氨酸解氨酶（PAL）的活性在接种叶片的叶柄和接种叶片以上的茎中的瞬时增加，在9和12小时，分别接种后的活性峰值。而PAL活性在接种后的18 h内持续缓慢上升。在接种植株的健康叶片中没有检测到PAL活性的增加。两种苯甲酸衍生物，水杨酸（SA）和4-羟基苯甲酸（4 HBA），开始积累在韧皮部流体的时间PAL活性开始增加，达到最大浓度接种后15小时。SA和4 HBA在韧皮部液中的积累不受接种后6 h去除所有叶片的影响，接种前从根切下的幼苗仍然积累了高水平的SA和4 HBA。这些结果表明SA和4 HBA在茎和叶柄中响应于来自接种叶的移动的信号而从头合成。
Cucumber (Cucumis sativa) leaves infiltrated with Pseudomonas syringae pv. syringae cells produced a mobile signal for systemic acquired resistance between 3 and 6 h after inoculation. The production of a mobile signal by inoculated leaves was followed by a transient increase in phenylalanine ammonia-lyase (PAL) activity in the petioles of inoculated leaves and in stems above inoculated leaves; with peaks in activity at 9 and 12 h, respectively, after inoculation. In contrast, PAL activity in inoculated leaves continued to rise slowly for at least 18 h. No increases in PAL activity were detected in healthy leaves of inoculated plants. Two benzoic acid derivatives, salicylic acid (SA) and 4-hydroxybenzoic acid (4HBA), began to accumulate in phloem fluids at about the time PAL activity began to increase, reaching maximum concentrations 15 h after inoculation. The accumulation of SA and 4HBA in phloem fluids was unaffected by the removal of all leaves 6 h after inoculation, and seedlings excised from roots prior to inoculation still accumulated high levels of SA and 4HBA. These results suggest that SA and 4HBA are synthesized de novo in stems and petioles in response to a mobile signal from the inoculated leaf.