A novel sensor to map auxin response and distribution at high spatio-temporal resolution

Area of Science:

• Plant Biology
• Molecular Biology
• Developmental Biology

Background:

• Auxin is a crucial plant hormone regulating development.
• Current tools for visualizing auxin dynamics are limited.
• Auxin signaling involves the degradation of Aux/IAA repressor proteins.

Purpose of the Study:

• To engineer a novel auxin signaling sensor for dynamic visualization.
• To assess the sensor's utility in mapping auxin distribution and response.
• To provide high-resolution spatio-temporal information on plant hormone signaling.

Main Methods:

• Fusion of VENUS fluorescent protein to the Aux/IAA auxin-interaction domain (DII).
• Expression of the DII-VENUS sensor in Arabidopsis thaliana under a constitutive promoter.
• Analysis of DII-VENUS abundance dependence on auxin, co-receptors, and proteasome activity.

Main Results:

• DII-VENUS abundance is regulated by auxin, TIR1/AFBs, and proteasome activity.
• The sensor successfully maps relative auxin distribution at cellular resolution across tissues.
• DII-VENUS enabled visualization of dynamic auxin changes during root gravitropism and shoot apex development.

Conclusions:

• DII-VENUS serves as a valuable tool for studying auxin distribution and signaling dynamics.
• The sensor provides high-resolution spatio-temporal data crucial for understanding plant development.
• This approach advances the study of hormone responses in plants.