AMYL EXPRESSION DURING WHEAT SEED-GERMINATION

The expression pattern of alpha-Amyl, a gene coding for high-pi alpha-amylase, has been studied during wheat (Triticum aestivum) seed germination using both Northern-blot and in situ hybridisation, At early stages of germination (24 h after imbibition) this gene was exclusively expressed in the scutellar epithelium. The expression in this tissue was transient and independent of GA(3). At later stages of germination, after 48 h of imbibition, expression in the epithelium decreased while alpha-Amyl mRNA accumulated in the aleurone layer, In this tissue, where alpha-Amyl expression is regulated by GA(3), a gradient could be detected with the embryo-proximal aleurone cells showing a higher level of expression than distal cells, These results show temporal and spatial expression of alpha-Amyl during germination of the wheat grain.