HarpinEa促进烟草和蕃茄生长和诱导抗虫的信号通路

用HarpinEa对野生型烟草进行了处理，结果发现，HarpinEa能够促进植株的生长(Enhanced Plant Growth，EPG)，提高内源SA和乙烯的水平，诱导对烟蚜的抗性(Insect Resistance，IR)。相应地，半定量RT-PCR方法检测表明，harpinEa诱导野生型烟草中水杨酸(salicylic acid，SA)信号传导重要调控基因NPR1、效应基因PR-1a、PR-1b以及乙烯信号通路中的ACS6、ETR1、EIN2等基因的表达。在不积累SA的NahG烟草上，harpinEa诱导EPG和IR的能力不受影响，但RP-1a、PR-1b基因的表达水平显著降低。这些结果说明，harpinEa诱导EPG和IR过程与SA信号通路无关，而可能受乙烯信号调节。

Growth and Insect Resistance Pathways Activated by HarpinEa in Tobacco and Tomato

It has been demonstrated that the induction of enhanced plant growth (EPG) and insect resistance (IR) by harpin Ea is attributed to the activation of the ethylene signaling pathways. Showed here is that harpin Ea uses a similar mechanism for the induction of EPG and IR in tobacco and Arabidopsis. Treatment of wild-type tobacco with harpin Ea also resulted in IR to green peach aphid and EPG. Both SA and ethylene accumulated in tobacco shortly following harpin Ea application, followed by induced or enhanced expression of several genes. Genes tested include NPR1 and PR-1a involved in SA signaling, PR-1b usually associated mediated by ethylene or JA for expression, and ACS6, ETR1, and EIN2 that control ethylene biosynthesis, acceptance by plants, and ethylene signal transmission, respectively. In addition, NahG plants also showed EPG and IR following treatment with harpin Ea. Therefore, signaling schemes for the induction of EPG and IR in tobacco are apparently similar to those in Arabidopsis.