Discovery may Help Scientists Design Better Plant Growth Regulators

Gibberellins (GA) are phytohormones that play important roles in key developmental processes such as stem elongation, cell division, seed germination and flowering. Biosynthetic inhibitors of gibberellin are widely used to regulate crop growth. Scientists have recently identified its receptor-GD1. Binding of the hormone to the receptor leads to the recognition of the growth-repressing DELLA family of transcription factors (molecules that regulate gene expression). Previous studies suggest that gibberellins stimulate the aforementioned developmental events by causing the destruction of DELLA.

Scientists at the Nara Institute of Science and Technology in Japan and Duke University in the US independently describe the crystal structure of gibberellin receptors from Arabidopsis and rice, providing deeper insights on how the phytohormone is perceived by plants. The structures reveal a receptor recognition mechanism that is distinct from auxins. Now that the structure of the receptor has been determined, scientists can design more effective and cheaper gibberellin-like growth regulators for use in agriculture.

The papers published are available at http://dx.doi.org/10.1038/nature07519 http://dx.doi.org/10.1038/nature07546 A summary article is available at http://dx.doi.org/10.1038/456455a