Crop Biotech Update

Transcription Factor Links Abscisic Acid and Gibberellin Interaction in Rice

October 15, 2010

Plant hormones such as abscisic acid (ABA) and giberrellic acid (GA) are important factors in controlling plant growth and development through various sets of complex interactions. Scientists are seeking to understand these interactions because of their role in developing crops with improved yield and resistance to environmental stress. Mahmoud Yaish of the University of Guelph, Canada, and other researchers found a transcription factor (OsAP2-39) in rice that codes for the AP2 domain, which directly controls a key ABA biosynthetic gene (OsNCED-1) and another gene (EUI) coding for a GA deactivation protein. They observed that ABA stimulated the expression of EUI leading to the deactivation of GA. ABA was also found to prevent the expression of OsAP2-39, in effect reducing the synthesis of ABA. Thus, OsAP2-39 connects ABA synthesis and GA deactivation, resulting to ABA/GA balance and regulation.

The open-access article can be viewed at http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1001098#abstract1.