Temporal and Spatial Expression of the -Amylase Gene during Seed Germination in Rice and Barley

Abstract

We have analyzed the in situ hybridization of α-amyl-ase genes in rice and barley seeds. There are some similarities in the expression pattern between the rice and barley α-amylase genes, RAmylA and Amyl. Both are gib-berellin-inducible, the expression of these genes initiates in the scutellar epithelium and continues in the aleurone layer, and the gene expression in the aleurone layer initiates from a region close to the embryo. However, we also identified some differences in the pattern of gene expression between these species, (i) expression of the rice a-amylase gene is initiated in the terminal regions of scutellar epithelium, but in the middle-basal region in barley, (ii) the progress of the gene expression in the rice aleurone layer is faster than that in barley. Additionally, analyses using embryo mutants of rice indicate that the scutellum has a responsibility for RAmylA gene expression in aleurone layer cells.