黄瓜卷须缠绕过程中小G蛋白活性变化

攀爬植物的卷须是对机械刺激极为敏感的器官。拟南芥(Arabidopsis thaliana)小G蛋白能够响应机械刺激调控自身发育, 但小G蛋白信号是否在卷须感受机械刺激发生缠绕过程中发挥作用目前尚不清楚。该研究以黄瓜(Cucumis sativus)为实验材料, 对其卷须受机械刺激缠绕过程中小G蛋白活性进行了探讨。ROP活性检测结果表明, 在卷须缠绕过程中小G蛋白CsROP6的活性显著增强; 同时, 质谱鉴定结果显示, 卷须缠绕过程中生长素的含量明显增加。进一步的实验表明, 外源生长素处理能明显增强CsROP6的活性, 暗示黄瓜卷须在缠绕过程中受机械刺激可能通过生长素增强ROP活性, 且机械刺激激活小G蛋白信号在不同植物中存在一定的保守性。

Changes of Small GTPases Activity During Cucumber Tendril Winding

Tendrils of climbing plants are highly sensitive to mechanical stimuli. Small GTPases signals can be activated by mechanical stimulation which regulate development in Arabidopsis, but whether small GTPases signals play a role in the entanglement of tendrils response to mechanical stimuli is unknown. In this study, the activity of small GTPases in cucumber tendril after mechanical stimulation was investigated using Cucumis sativus, and ROP activity detection results showed that the activity of small GTPases CsROP6 was significantly enhanced during tendril winding. Meanwhile, mass spectrometry revealed that auxin content increased significantly during tendril winding. Further experiments showed that exogenous auxin treatment increased the activity of CsROP6, suggesting mechanical stimulation might activate ROP6 activity through auxin during tendril winding. This study suggests that mechanical stimulation of small GTPases signals may be conserved in different plants.