辣子草水浸提液对蚕豆叶保卫细胞的影响

Effect of Aqueous Extract of Galinsoga parviflora Cav. on Guard Cells of Vicia faba L.

为了探讨入侵植物辣子草(Galinsoga parviflora Cav.)的化感作用机制,以蚕豆叶下表皮为材料,采用表皮条活性分析法研究了辣子草水浸提液诱导气孔保卫细胞凋亡及其信号调节机制。结果表明:在辣子草水浸提液作用下,蚕豆叶保卫细胞活性降低,细胞核出现了畸形以及固缩、降解或拉长等典型的凋亡特征,且随着水浸提液浓度增加。当处理浓度为0.05 g/m L时,保卫细胞的死亡率和核异常率分别为90.53%和87.77%;在0.05 mmol/L Caspase抑制剂Z-VAD-FMK、0.1 mmol/L质膜钙离子通道抑制剂La Cl3、0.1 mmol/L硝酸还原酶抑制剂Na N3和0.5 mmol/L活性氧清除剂抗坏血酸(As A)作用下,辣子草水浸提液诱导的保卫细胞死亡率均显著降低,分别为辣子草水浸提液处理组的19.44%、16.12%、50.08%、23.67%。由此表明,辣子草水浸提液诱导蚕豆保卫细胞发生了Caspase依赖性的细胞凋亡,同时ROS、NO、Ca2+参与了保卫细胞凋亡的信号转导过程。

To explore the allelopathy mechanism of an invasive plant（Galinsoga parviflora Cav.） in China,the leaf guard cells apoptosis and signal regulation of broad bean（Vicia faba L.） epidermis were treated with the aqueous extracts of G. parviflora were studied. The results showed that when broad bean was exposed to the aqueous extracts,its guard cell viabilities reduced,the typical features of apoptosis including nuclear pyknotic,malposition,stretch and degradation were observed,and these effects were concentration-dependent. The mortality rates and the abnormal nuclei rates were 90. 53 % and 87. 77 %,respectively while the aqueous extracts concentration were 0. 05 g / m L.However,the mortality rates significantly decreased when the strips exposed to the aqueous extracts combined with different concentrations of plasma membrane Ca2 ＋channel blocker La Cl3 or nitrite reductase inhibitor Na N3 or antioxidant ascorbic acid（As A） or Caspase inhibitor（ZVAD-FMK）,which were 19. 44 %,16. 12 %,50. 08 %,23. 67 %. These results suggested that the apoptosis of broad bean induced by the allelochemical stress of G. parviflora was associated with Ca2 ＋,NO and ROS.