BTH诱导甜瓜愈伤组织活性氧代谢和抗性酶活性的信号途径

通过对含有苯并噻二唑(BTH)、咖啡酸(CA)或氯化钴(CC)等不同MS培养上甜瓜愈伤组织的研究,测定了超氧阴离子(O2■)产生速率、过氧化氢(H2O2)含量及抗性相关酶活性的变化,探讨了BTH诱导的甜瓜ROS代谢和抗性酶活性及其相关的信号途径。结果表明,CA可以消除BTH对甜瓜愈伤组织O2■增加和H2O2积累的诱导作用;CA或CC能够部分抵消BTH对SOD增强的诱导作用;CC对BTH诱导的POD增强具有抑制效应,CA+CC可完全消除BTH对POD的诱导作用;CA和CC均能促进BTH对PAL增强的诱导作用,且具有协同效应。BTH对甜瓜O2■升高、H2O2积累和CAT降低的诱导主要通过SA途径实现,对POD的影响主要通过ET途径实现,对SOD升高的诱导通过SA和ET 2条途径实现,而对PAL活性的影响通过ET和SA以外的途径实现。

The signal pathway of melon calli ROS metabolism and defensive enzyme activities induced by BTH

The melon calli were cultured in dark(25±2) ℃ on MS medium contained 5 mmol·L-1 coffeic acid(CA) and/ or 10 mmol·L-1 CoCl2(CC),while benzothiadiazole(BTH) were sprayed on the calli.The production rate of O2■,content of H2O2 and the activities of SOD,CAT,POD,PPO,PAL were determined.The result showed that CA inhibited the induction of BTH on O2■ rate,H2O2 production and CAT decrease.While CC stimulated O2■ rate,but had no effect on BTH induced H2O2 production and CAT decrease.Either CA or CC could partially inhibit the increase of SOD activity induced by BTH,and CA+CC completely counterbalanced the effect of BTH on SOD.CC eliminated POD increase induced by BTH,while CA showed no effect on this.Both CA and CC promoted the increase of PAL induced by BTH.These results demonstrate that the induction of BTH on CAT activity,O2■ rate and H2O2 production is through SA-dependent pathway,the induction of BTH on POD activity is through ET-dependent pathway,and the effect of BTH on SOD activity is through SA-and ET-dependent pathways,while the induction of BTH on PAL may be via signal transduction other than SA-or ET-dependent pathway.