Plant Signal Behav. 2013 Oct;8(10):doi: 10.4161/psb.26791. doi: 10.4161/psb.26791.
Cytokinin has long been shown to be an essential modulator of growth and development in plants. However, its implications in plant immunity have only recently been realized. The interaction between jasmonate and salicylate pathways is regarded as a central backbone of plant immune defense. However, the effect of cytokinin on the jasmonate and salicylate mediated balance in plant immunity is still not known. Here, we analyze the impact of cytokinin on the jasmonate-salicylate antagonism in Arabidopsis immunity regarding infection with hemibiotrophic pathogen Pseudomonas syringae pv tomato DC3000 (Pst DC3000). Systems biology analysis of a refined hormone immune pathway model provides insights into the impact of cytokinin on the balance between jasmonate and salicylic acid pathways in Arabidopsis. Targeted experiments validate model simulations monitoring bacterial growth in wild type plants as well as in jasmonate pathway mutants. An integrated analysis shows that CK promotes the SA pathway of plant immunity and does not promote JA-mediated Arabidopsis susceptibility against infection with Pst DC3000. Finally, we discuss these results in the context of an emerging model of auxin-cytokinin antagonism in plant immunity.
细胞分裂素长期以来一直被证明是植物生长和发育的重要调节剂。然而，其在植物免疫中的意义最近才被认识到。茉莉酸和水杨酸途径的相互作用被认为是植物免疫防御的核心骨干。然而，细胞分裂素对植物免疫中茉莉酸和水杨酸介导的平衡的影响尚不清楚。在这里，我们分析了细胞分裂素对拟南芥免疫中茉莉酸-水杨酸拮抗作用的影响，涉及半活体病原菌丁香假单胞菌 pv 番茄 DC3000（Pst DC3000）的感染。对精细化激素免疫途径模型的系统生物学分析提供了对细胞分裂素对拟南芥中茉莉酸和水杨酸途径之间平衡影响的深入了解。靶向实验验证了模型模拟，监测野生型植物和茉莉酸途径突变体中的细菌生长。综合分析表明，CK 促进了植物免疫的 SA 途径，而不会促进 JA 介导的拟南芥对 Pst DC3000 感染的敏感性。最后，我们在植物免疫中生长素-细胞分裂素拮抗作用的新兴模型背景下讨论了这些结果。
