Arabidopsis bZIP11 Is a Susceptibility Factor During Pseudomonas syringae Infection

Area of Science:

• Plant-microbe interactions
• Molecular plant pathology
• Plant physiology

Background:

• Plant nutrient secretion systems are crucial for pathogen infection.
• Some bacteria use transcription activator-like (TAL) effectors to induce SWEET sucrose efflux transporters.
• Pseudomonas syringae pv. tomato strain DC3000 lacks TAL effectors but induces SWEETs via unknown mechanisms.

Purpose of the Study:

• To investigate the role of host transcription factors in nutrient acquisition for bacterial pathogens.
• To identify potential regulators of nutrient transporters, including SWEETs and UmamiT transporters, in Arabidopsis.
• To test the hypothesis that Pseudomonas spp. utilize host transcription factors involved in secretory programs for nutrient access.

Main Methods:

• Bioinformatic analysis to identify potential transcription factor regulators.
• Inducible downregulation and overexpression of the Arabidopsis bZIP11 gene.
• Quantification of Pseudomonas syringae pv. tomato strain DC3000 growth in Arabidopsis leaves.

Main Results:

• Bioinformatic analysis identified Arabidopsis bZIP11 as a regulator of SWEET and UmamiT transporters.
• Downregulation of bZIP11 reduced P. syringae pv. tomato DC3000 growth.
• Overexpression of bZIP11 increased P. syringae pv. tomato DC3000 growth.

Conclusions:

• The Arabidopsis bZIP11 transcription factor plays a critical role in facilitating P. syringae pv. tomato DC3000 infection.
• bZIP11-regulated transcription programs are essential for maximizing pathogen titer in plant leaves.
• Pathogens may alter host transcription factor expression to promote nutrient efflux and support infection.