Reference "Structural organization and differential expression of rice alpha-amylase genes"

Reference ID

1522

Title

Structural organization and differential expression of rice alpha-amylase genes

Source

Nucleic acids research, 1990, vol. 18, pp. 7007-7014

Authors (4)

Huang-N	Koizumi-N
Reinl-S	Rodriguez-R-L

Abstract

Rice alpha-amylases are encoded by a multigene family that has previously been
classified into 5 hybridization groups. DNA sequence and Southern blot analysis
identified three genes (RAmy1A, RAmy1B and RAmy1C) in Group 1 with DNA sequence
identity of at least 90%. Hybridization Group 2 is represented by only one gene,
RAmy3D, which is identical to a previously characterized cDNA, pOS137. RAmy3D is
physically linked to the sole representative of Group 5, RAmy3E. The identity
between these two genes is 81.4% in the coding region but less than 50% in the
5' and 3' flanking regions. Northern blot analysis and RNA-PCR were used to
detect the expression of alpha-amylase genes in various tissues. Alpha-amylase
mRNA was abundant in germinating seeds and callus. Some genes were also
expressed at much lower levels in roots, young leaves and immature seeds. RAmy1A
and RAmy3E were expressed in all tissues while RAmy3D was expressed in all
tissues except the immature seeds. RAmy1B was weakly expressed only in callus.
RAmy1A transcript was most abundant in the germinating seeds, while RAmy3D and
RAmy3E transcripts were most abundant in callus and immature seeds,
respectively.