RACK1A positively regulates opening of the apical hook in Arabidopsis thaliana via suppression of its auxin response gradient

Abstract

Apical hook development is an ideal model for studying differential growth in plants and is controlled by complex phytohormonal crosstalk, with auxin being the major player. Here, we identified a bioactive small molecule that decelerates apical hook opening in Arabidopsis thaliana. Our genetic studies suggest that this molecule enhances or maintains the auxin maximum found in the inner hook side and requires certain auxin signaling components to direct target of this compound. We present data in support of RACK1A playing a positive role in apical hook opening by activating specific auxin signaling mechanisms and negatively regulating the differential auxin response gradient across the hook, thereby adjusting differential cell growth, an essential process for organ structure and function in plants.

Keywords

apical hook; auxin; Arabidopsis; differential cell growth

Published in

Proceedings of the National Academy of Sciences of the United States of America
2025, volume: 122, number: 30, article number: e2407224122
Publisher: NATL ACAD SCIENCES

SLU Authors

• Ma, Qian

  • Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
    

• Liu, Sijia

  • Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
    

• Doyle, Siamsa

  • Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
    

• Raggi, Sara

  • Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
    

• Barange, Deepak Kumar

  • Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
    
  • Umeå University

• Ratnakaram, Hemamshu

  • Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
    

• Wingsle, Gunnar

  • Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
    

• Novak, Ondrej

  • Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
    
  • The Czech Academy of Sciences

• Robert, Stephanie

  • Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Botany

Publication identifier

• DOI: https://doi.org/10.1073/pnas.2407224122

Permanent link to this page (URI)

https://res.slu.se/id/publ/143283