分枝列当寄生甜瓜时吸器形成过程中内源激素的动态变化

本研究采用石蜡切片和显微观察分析分枝列当寄生甜瓜时的吸器形成过程, 利用液相色谱-质谱联用 (LC-MS) 检测吸器形成过程中24种植物内源激素变化。结果表明:分枝列当种子在接种甜瓜根部第3 天开始萌发, 接种第7 天分枝列当吸器顶端稳固地附着在寄主根部, 吸器侵入甜瓜根皮层, 并在甜瓜根皮层细胞内扩展, 扩展过程中形成大量的爪状结构, 接种第11 天时分枝列当吸器细胞与寄主根维管束连接。共有17种植物激素参与了吸器形成过程, 其中生长素类吲哚-3-甲醛含量在列当吸器形成过程中降低了83.36%，细胞分裂素类反式玉米素核苷的含量在增长了5.02倍;油菜素内酯含量增长了481.95倍, 推测这3类植物激素在分枝列当吸器形成过程中可能起到重要的调控作用。

Dynamic change of endogenous hormones during the formation of haustorium of Orobanche aegyptiaca parasitizing melon

In this study, the formation process of haustorium of Orobanche aegyptiaca was analyzed by paraffin section and microscopic observation, and the dynamic changes of endogenous hormones in O. aegyptiaca at different stages of haustorium formation during parasitism to melon roots were detected by liquid chromatography- mass spectrometry (LC-MS). The results show that the seeds of O. aegyptiaca began to germinate on the third day after inoculation, the haustorium top was firmly attached to the melon root on the 7th day, and then haustorial cell invaded the cortex of melon root, forming a large number of claw-like structures in the cell layer of the cortex of melon root. On the 11th day, haustorial cells were connected with host vascular bundle. Phytohormone test results showed that a total of 17 phytohormones were involved in the formation process of haustorium in O. aegyptiaca, and the contents of auxin, cytokinin and brassinolide changed significantly. The content of auxin indole-3-carboxaldehyde decreased by 83.36%, the content of cytokinin-like trans-zeatin-riboside increased by 5.02 times and brassinolide increased by 481.95 times in the formation process of haustorium. These three phytohormones might play an important role in regulating haustorium formation in O. aegyptiaca.