In a powerful example of the utility of the Arabidopsis plant genome sequence, an international collaboration of researchers has discovered a key component in the regulation of seed sprouting.It has long been known that under proper environmental conditions of light and moisture, the plant hormone gibberellin initiates growth of the embryonic plant that resides inside a seed. But precisely how gibberellin (GA) translates environmental cues into the complex gene response necessary for seed germination has remained fairly mysterious. Until recently.
In Friday's issue of Genes & Development, researchers from the National University of Singapore and the John Innes Center in Norwich, England, report that they have determined that the protein, RGL2, acts as a molecular crossroad linking the GA-mediated signaling pathway and environmental moisture cues.
Dr. Jinrong Peng and colleagues identified the RGL2 gene product as a member of a protein family known to be involved in plant growth and development. Using various genetic and biochemical approaches, Dr. Peng and colleagues discovered that RGL2 mRNA transcripts accumulate upon imbibition and, in the absence of GA, RGL2 prevents seed germination. However, in the presence of GA, RGL2 activity is suppressed and germination begins.
Dr. Peng's work establishes RGL2 as a negative regulator of seed germination and as a critical player in the integration of endogenous and exogenous cues regulating seed germination.
Genes & Development is a publication of the Cold Spring Harbor Laboratory Press.
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[Contact: Heather Cosel-Pieper]
04-Mar-2002
