几种经济红藻中茉莉酸合成途径的关键物质

为研究几种经济红藻中茉莉酸合成途径的关键物质,实验采用液相色谱—质谱联用技术(LC-MS)对茉莉酸生物合成途径相关物质建立检测方法,并对龙须菜、坛紫菜受到机械损伤时各物质的变化情况进行检测。以100%甲醇提取茉莉酸(JA)、茉莉酸甲酯(MeJA)、12-氧-植物二烯酸(12-OPDA)和13-氢过氧化亚麻酸(13-HpOTE),利用XBridge TM C18色谱柱,以甲醇/水为流动相分离4种物质。优化条件下4种物质得到良好分离,加标回收率为81.23%～90.25%,检测限为0.04～0.56 ng/mL,灵敏度高。坛紫菜、龙须菜和真江蓠3种红藻中,坛紫菜中未检测到JA和13-HpOTE,4种物质均在另外2种藻中检测到。龙须菜受机械损伤胁迫后,4种物质在短时间内得到积累,其中13-HpOTE响应迅速。研究表明,红藻中可能存在类似于植物的茉莉酸合成途径,并参与对损伤的胁迫响应。

Key compounds in the synthesis pathway of jasmonic acid in several economic red algae

This study was designed to research the key compounds of jasmonic acid synthesis pathway in several economic red algae. A liquid chromatography-mass spectrometry (LC-MS) was used to establish the detection method of compounds involved in the biosynthetic pathway of jasmonic acid, and the changes of these compounds were detected in Gracilariopsis lemaneiformis and Pyropia haitanensis when they were subjected to mechanical damage. Jasmonic acid (JA), methyl jasmonate (MeJA), 12-oxy-phytodienoic acid (12-OPDA) and 13-hydroperoxylinolenic acid (13-HpOTE) were extracted with 100% methanol, and the four compounds were separated by XBridge^TM C₁₈ chromatographic column with methanol/water as mobile phase. The results showed that the four compounds could be separated well under optimal conditions. The recoveries of the four compounds were 81.23%-90.25%, and the detection limits of the method were between 0.04 and 0.56 ng/mL, indicating that the high sensitivity of this method. These four compounds in G. lemaneiformis, P. haitanensis and Gracilaria asiatica were analyzed. In addition to no JA and 13-HpOTE detected in P. haitanensis, four compounds were detected in the other two species of red algae. The content changes of these compounds in G. lemaneiformis under mechanical damage stress were analyzed, and it was found that when the alga was stressed, the contents of them were accumulated within a short time, and the responses of them were rapid. After P. haitanensis was mechanically damaged, JA production was detected, but the response rates of these compounds were slower than G. lemaneiformis. These results suggest that some red algae may have a similar pathway of jasmonic acid synthesis to that of plants, and also may participate in the stress response to mechanical injury.