MAPK级联在玉米抗病反应和植保素代谢调控中的作用分析
利用mitogen-activated protein kinase (MAPK)级联抑制剂U0126和PD98059特异抑制MAPK信号传递途径后,使用禾谷镰刀菌侵染或脱落酸(ABA)处理玉米自交系Mo17幼苗,利用qRT-PCR分析植保素关键基因表达情况,观察MAPK级联对玉米响应禾谷镰刀菌侵染的情况。结果表明：抑制MAPK级联后,玉米叶片对禾谷镰刀菌侵染更加敏感,发病率显著提高,禾谷镰刀菌对植保素相关基因TPS6、An2、CYP71Z18、KSL5和TPS1的诱导受到抑制,且转录因子WRKY79的表达也被抑制,这说明在玉米叶片中植保素的产生受MAPK级联的调控。而且玉米根系在MAPK级联被抑制后,ABA对这些基因表达的诱导同样受到抑制。这说明MAPK级联参与植物抗病反应,在玉米叶片和根部MAPK级联可能通过调控转录因子ZmWRKY79参与对植保素代谢的调控,为玉米抗病反应机理研究提供理论依据。
英文摘要:
Mitogen-activated protein kinase (MAPK) cascade inhibitor U0126 and PD98059 were applied to maize inbred line Mo17 leaves and roots that were infected or treated by Fusarium graminearum or abscisic acid (ABA), respectively. The genes of maize phytolaexin biosynthesis were analyzed with qRT-PCR. In the mean time, disease development and ratio one maize leaves were recorded. Inhibition of MAPK cascade significantly reduces plant disease resistance and resulted in higher disease development and ratio, indicating that MAPK cascade positively regulates disease defense in maize. Furthermore, pathogen infection induced expression of maize phytoalexin biosynthetic genes. Such induction was affected by MAPK inhibition, suggesting that phytoalexin metabolism is controlled by MAPK cascade in maize leaves. Moreover, in roots, ABA treatment significantly induced these gene expressions. Such induction was compromised after MAPK cascade was inhibited, indicating that MAPK cascade is involved in phytoalexin accumulation by ABA in maize roots.The expression of transcription factor ZmWRKY79, a regulator of maize terpenoid phytoalexins, was also compromised after MAPK cascade was inhibited. MAPK cascade positively regulates maize disease defense, and regulates maize phytoalexin biosynthetic genes by ZmWRKY79, which would provide the cue for comprehensive clarification of MAPK cascade in maize.
查看全文
;
