First, second, third, and fifth authors: Department of Plant Medicine, and fourth author: Department of Environmental Science and Engineering, National Pingtung University of Science and Technology, Pingtung, Taiwan.
Phytopathology. 2018 Dec;108(12):1467-1474. doi: 10.1094/PHYTO-03-18-0100-R. Epub 2018 Nov 5.
Bacterial soft rot is a devastating disease affecting a variety of vegetable crops worldwide. One strategy for controlling this disease could be the ectopic expression of the plant ferredoxin-like protein (pflp) gene. PFLP was previously shown to intensify pathogen-associated molecular pattern-triggered immunity (PTI), an immune response triggered, for example, by the flagellin epitope flg22. To gain further insight into how PFLP intensifies PTI, flg22 was used as an elicitor in Arabidopsis thaliana. First, PFLP was confirmed to intensify the rapid generation of HO, callose deposition, and the hypersensitive response when coinfiltrated with flg22. This response correlated with increased expression of the FLG22-induced receptor kinase 1 gene, which is part of the mitogen-activated protein kinase (MAPK) pathway. Although the increased response to flg22 alone did not depend on the MAPK pathway genes MEKK1, MKK5, and MPK6, the protective effect of PFLP decreased when plants mutated in these genes were inoculated with Pectobacterium carotovorum subsp. carotovorum. Furthermore, expression of PR1 and PDF1.2 also increased upon treatment with flg22 in the presence of PFLP. Taken together, these results suggest that activation of the MAPK pathway contributes to the increased resistance to bacterial soft rot observed in plants treated with PFLP.
细菌软腐病是一种全球性的破坏性疾病，影响着多种蔬菜作物。一种控制这种疾病的策略可能是异位表达植物铁氧还蛋白样蛋白（pflp）基因。先前的研究表明，PFLP 可以增强病原相关分子模式触发的免疫（PTI），这是一种由鞭毛蛋白表位 flg22 触发的免疫反应。为了更深入地了解 PFLP 如何增强 PTI，我们在拟南芥中使用 flg22 作为诱导剂。首先，当与 flg22 共浸润时，PFLP 被证实可以增强 HO 的快速产生、胼胝质沉积和过敏反应。这种反应与 FLG22 诱导的受体激酶 1 基因的表达增加相关，该基因是丝裂原活化蛋白激酶（MAPK）途径的一部分。尽管单独对 flg22 的反应增加并不依赖于 MAPK 途径基因 MEKK1、MKK5 和 MPK6，但当用 Pectobacterium carotovorum subsp. carotovorum 接种突变这些基因的植物时，PFLP 的保护作用降低。此外，在 PFLP 存在的情况下，用 flg22 处理后 PR1 和 PDF1.2 的表达也增加了。总之，这些结果表明，MAPK 途径的激活有助于用 PFLP 处理的植物对细菌软腐病的抗性增强。
