"Understanding how plants grow is fundamental to improving crop yields and resilience," says Prof. Sun Linfeng from the University of Science and Technology of China (USTC). In a groundbreaking discovery, USTC researchers have unveiled the molecular mechanism of auxin import in plants, a critical process for growth and development.
Published in Cell on May 15, the study details how the AUX1 protein transports auxin into plant cells using a proton concentration gradient. This discovery, made in China, provides the first glimpse into how the AUX1/LAX protein family functions.
The team, led by Profs. Sun Linfeng, Liu Xin, and Tan Shutang, used cryo-electron microscopy to determine the high-resolution structures of AUX1. These structures revealed the protein's architecture and how it binds to auxin, offering insights into directional growth and root development.
The research also identified key residues, like His249 (H249), crucial for auxin recognition. Mutagenesis and physiological experiments confirmed the importance of these residues in plant growth. Molecular dynamics simulations further clarified how inhibitors like CHPAA block auxin transport.
This breakthrough offers potential applications in agriculture. By understanding and manipulating auxin transport, scientists can develop crops with improved growth, enhanced root systems, and better stress responses. This could lead to higher yields and more sustainable agricultural practices.