Actin Depolymerization Factor ADF1 Regulated by MYB30 Plays an Important Role in Plant Thermal Adaptation

Area of Science:

• Plant Biology
• Molecular Biology
• Biochemistry

Background:

• Actin filaments are crucial for plant adaptation to environmental stresses, including high temperatures.
• The precise molecular mechanisms governing actin filament dynamics in plant thermal adaptation are not fully understood.

Purpose of the Study:

• To investigate the role of Arabidopsis actin depolymerization factor 1 (AtADF1) in plant thermal adaptation.
• To elucidate the regulatory mechanisms of AtADF1 under high-temperature conditions.

Main Methods:

• Gene expression analysis of AtADF1 under heat stress.
• Phenotypic analysis of AtADF1 mutants and overexpression lines under high temperatures.
• Investigation of actin filament stability in response to AtADF1 levels.
• Electrophoretic mobility shift assays and genetic analysis to determine AtMYB30 regulation of AtADF1.
• Homology analysis and functional characterization of Chinese cabbage BrADF1.

Main Results:

• High temperatures repressed AtADF1 expression and increased actin filament stability.
• AtADF1 mutation promoted growth under heat, while overexpression inhibited it, correlating with actin filament stability.
• AtMYB30 directly bound to the AtADF1 promoter and promoted its transcription under high temperatures.
• BrADF1 exhibited similar functions to AtADF1, affecting plant growth and actin filament organization.

Conclusions:

• ADF1 acts as a key regulator in plant thermal adaptation by counteracting high-temperature-induced actin filament stabilization.
• AtMYB30 directly controls AtADF1 expression in response to heat stress.
• ADF1's role in thermal adaptation is conserved across plant species, as evidenced by BrADF1 function.