中文摘要：

以海洋红藻龙须菜为材料,建立了5种内源性植物激素吲哚乙酸（IAA）、脱落酸（ABA）、茉莉酸（JA）、水杨酸（SA）、肉桂酸（RA）的GC-MS微量检测方法,并运用该方法初步研究了龙须菜中5种植物激素对不同浓度氮胁迫的响应规律。结果表明,最优的实验条件为：样品用正丙醇：水：HCl（2：1：0.002）提取,HLB固相萃取柱纯化,三甲基硅烷基重氮甲烷衍生化,GC-MS分析测定。5种植物激素的线性方程的相关系数r2为0.9943—0.9998,加标回收率为76.7%—104.3%,相对标准偏差为1.4%—2.9%,方法检出限为0.010—0.025μg/ml。该方法简便、灵敏、准确、重现性好。与Provasoli正常培养基相比,低氮和高氮胁迫条件下龙须菜IAA含量均降低;而ABA、JA和RA含量均在胁迫前期含量迅速升高,后期逐渐下降;SA含量在低N胁迫前期上升较快,后期逐渐下降;在高N胁迫下SA含量无显著变化。

英文摘要：

A highly sensitive method was developed for simultaneous determination of trace levels of endogenous phytohormones indole-3-acetic acid, abscisic acid, jasmonic acid, salicylic acid and cinnamic acid in marine red algae Gracilaria lemaneiformis using gas chromatography mass spectrometry （GC-MS） technology, and the response of five kinds of phytohormones of G. lemaneiformis under different nitrogen stresses was studied. The optimized method was as followings： samples were extracted by 1-propanol/H20/HC1 （2 ： 1 ： 0.002, V/V）, and the extracts were purified by SPE with HLB column, then derived by trimethylsilyldiazomethane, finally detected by GC-MS with SIM model. By using this method, the correlation coefficient of five kinds of phytohormones ranged from 0.9943 to 0.9998, and the average recov- eries varied from 76.7% to 104.3% with RSDs of 1.4%--2.9%, and LOD of 0.010--0.025ktg/ml. This method was showed to be a simple, sensitive, accurate, and reproducible method. When the G. lemaneiformis was stressed by low and high nitrogen concentration, the content of IAA was lower than the normal Provasoli medium group. But under low and high nitrogen stresses, the content of ABA, JA and RA increased sharply in the primary phase, then decreased gradually in the later phase. The content of SA under low nitrogen stress increased faster than the control group in the primary phase, but gradually declined in the later phase; the content of SA under high nitrogen stress showed no significant change than the control group.