H2S可能作为H2O2的上游信号介导茉莉酸甲酯诱导竹根姜对青枯菌的抗性

摘要

To explore the role of H2 S and H2O2 in the induced resistance of Bacterial Wilt of Ginger in ‘Zhugenjiang’ ginger with methyl jasmonate (MeJA),the seedlings of ‘Zhugenjiang’ ginger were treated with MeJA,NH2OH+MeJA,AsA+MeJA and sterile water,and incidence of disease were observed and several biological resistance components(H2S,H2O2,PAL,POD and lignin) were determined.The results showed that significantly low disease indexes of ‘Zhugenjiang’ ginger were detected in the treatment of MeJA,and the induced disease resistances of MeJA were inhibited by hydroxylamine (NH2OH) functioning as H2S synthesis inhibitor and ascorbic acid (AsA) served as H2O2 scavenger.Further study showed that the synthesis of H2S (mainly be synthesized by cysteine desulfhydrase) and H2O2,the activity of cysteine desulfhydrase,the activation of lignin synthases (PAL and POD) were significantly promoted.NH2 OH could reduce the activity of cysteine desulfhydrase and inhibit the synthesis of H2 O2 and H2 S.AsA could inhibit the synthesis of H2O2,and it had no effect on the synthesis of H2S and the activity of cysteine desulfhydrase.These results indicated that H2 S may play a role in the response of MeJA to disease-resistant as an upstream signal of H2 O2.By regulating the levels of H2S and H2O2,MeJA can activates the activity of lignin biosynthesis enzymes,promote the synthesis of lignin,and increase resistance against Ralstonia solanacearum.%为探讨H2S和H2O2在茉莉酸甲酯(MeJA)诱导竹根姜抗姜瘟病过程中的上下游关系,以竹根姜幼苗为研究对象,采用MeJA、NH2 OH+ MeJA、AsA+ MeJA、无菌水等进行喷雾,观察竹根姜发病情况,并对H2S、H2O2、苯丙氨酸解氨酶(PAIL)、过氧化物酶(POD)和木质素等指标进行检测.结果显示,MeJA处理可以显著降低竹根姜的病情指数,提高抗病性,而H2S合成抑制剂NH2 OH和H2 O2清除剂AsA均抑制MeJA诱导的抗病效果.进一步研究发现,MeJA能够明显促进H2S(主要由半胱氨酸脱巯基酶合成)和H2O2的合成以及半胱氨酸脱巯基酶的活性,提高木质素合成相关酶(PAL和POD)活性,促进木质素合成.H2S合成抑制剂NH2OH可降低半胱氨酸脱巯基酶的活性并抑制H2S和H2O2的产生,而H2 O2清除剂AsA可抑制H2O2的产生,但对H2S的合成和半胱氨酸脱巯基酶的活性没有影响.由此证明,H2S可能作为H2O2的上游信号参与竹根姜对MeJA的响应.MeJA在竹根姜细胞内进行有效的信号传导,通过调控细胞内下游信号分子H2S和H2 O2的产生,激活木质素合成相关酶的活性,促进木质素的合成,提高竹根姜对青枯菌的抗性.