Dual role of auxin in regulating plant defense and bacterial virulence gene expression during Pseudomonas syringae PtoDC3000 pathogenesis
Dual role of auxin in regulating plant defense and bacterial virulence gene expression during Pseudomonas syringae PtoDC3000 pathogenesis
复制标题
生长素在丁香假单胞菌 PtoDC3000 发病过程中调节植物防御和细菌毒力基因表达的双重作用
DOI：
10.1101/2019.12.29.881581
复制
发表时间：
2019
期刊：
影响因子：
--
通讯作者：
B. Kunkel
中科院分区：
文献类型：
--
作者：
A. Djami;Gregory A. Harrison;Christopher P. Harper;Renhou Wang;M. Prigge;M. Estelle;B. Kunkel
寄主激素生物学修饰是植物病原菌促进病害的一种常用策略。例如，细菌病原菌紫丁香假单胞菌PtoDC3000产生植物激素生长素(吲哚-3-乙酸，或IAA)，以促进PtoDC3000在植物组织中的生长。以前的研究表明，生长素可能通过多种机制促进PtoDC3000的发病，包括抑制水杨酸(SA)介导的宿主防御，以及一种似乎独立于SA的未知机制。为了测试寄主生长素信号在致病过程中是否重要，我们利用了生长素信号或感知受损的拟南芥品系。我们发现，在表达可诱导的显性axr2-1突变的植物中，生长素信号的中断导致细菌生长减少，这表明宿主生长素信号是正常对PtoDC3000敏感所必需的，并且这种表型依赖于SA介导的防御。然而，尽管表现出生长素感知能力的下降，TIR1afb1 afb4 afb5四重突变植株缺乏六个已知生长素辅助受体中的四个，支持细菌生长水平的增加。该突变体还表现出较高的IAA水平，表明在这些植物中增加的IAA可能不依赖于寄主生长素信号而促进PtoDC3000的生长，可能是通过直接作用于病原菌。为了支持这一点，我们发现IAA通过调节细菌毒力基因的表达，直接影响病原菌，无论是在液体培养还是在植物中。因此，除了抑制宿主防御外，IAA还作为一种微生物信号分子来调节细菌毒力基因的表达。
Modification of host hormone biology is a common strategy used by plant pathogens to promote disease. For example, the bacterial pathogen Pseudomonas syringae strain PtoDC3000 produces the plant hormone auxin (Indole-3-acetic acid, or IAA) to promote PtoDC3000 growth in plant tissue. Previous studies suggest that auxin may promote PtoDC3000 pathogenesis through multiple mechanisms, including both suppression of salicylic acid (SA)-mediated host defenses and via an unknown mechanism that appears to be independent of SA. To test if host auxin signaling is important during pathogenesis, we took advantage of Arabidopsis thaliana lines impaired in either auxin signaling or perception. We found that disruption of auxin signaling in plants expressing an inducible dominant axr2-1 mutation resulted in decreased bacterial growth, demonstrating that host auxin signaling is required for normal susceptibility to PtoDC3000, and this phenotype was dependent on SA-mediated defenses. However, despite exhibiting decreased auxin perception, tir1 afb1 afb4 afb5 quadruple mutant plants lacking four of the six known auxin co-receptors supported increased levels of bacterial growth. This mutant also exhibited elevated IAA levels, suggesting that the increased IAA in these plants may promote PtoDC3000 growth independent of host auxin signaling, perhaps through a direct effect on the pathogen. In support of this, we found that IAA directly impacted the pathogen, by modulating expression of bacterial virulence genes, both in liquid culture and in planta. Thus, in addition to suppressing host defenses, IAA acts as a microbial signaling molecule that regulates bacterial virulence gene expression.
登录
查看更多内容
影响因子：
3.3
作者：
C. Timpte;Allison K. Wilson;M. Estelle
通讯作者：
C. Timpte;Allison K. Wilson;M. Estelle
影响因子：
7.2
作者：
Earley, KW;Haag, JR;Pikaard, CS
通讯作者：
Pikaard, CS
DOI：
10.1073/pnas.1800529115
发表时间：
2018-03-27
影响因子：
11.1
作者：
Nobori, Tatsuya;Velasquez, Andre C.;Tsuda, Kenichi
通讯作者：
Tsuda, Kenichi
DOI：
10.1073/pnas.0600366103
发表时间：
2006-03-21
影响因子：
11.1
作者：
Liu, P;Nester, EW
通讯作者：
Nester, EW
影响因子：
7.7
作者：
Prigge, Michael J.;Platre, Matthieu;Estelle, Mark
通讯作者：
Estelle, Mark