Table 2.
Genomic sequences of two grain amaranth genes involved in sucrose and starch metabolism
| Gene | Size (bp)1 | No. Exon | No. Intron | Accesion number | Salient characteristics2 | Ref2 |
|---|---|---|---|---|---|---|
|
AhAGPS-1 |
5088 |
9 (99–297)3 |
8 (84–1048)3 |
JQ034321 |
The gene is highly similar (94% identity) to the B. vulgaris AGPB1 gene (GenBank X78899.1). The complexity of this gene is shared with other starch metabolism genes. The presence of a large first intron (1048 bp) suggests a possible role in regulating expression as observed for a sucrose synthase gene in Arabidopsis. The promoter region has MYCL and GCCF boxes which are needed in maize for the transcriptional regulation of the waxy gene coding for a GBSS. |
[46,58-60] |
| AhVI-1 | 5376 | 7 (9–857)3 | 6 (85–1015)3 | JQ012921 | Contains the expected seven exons generally conserved in the majority of acid invertase genes isolated from plants4. The AhVI-1 gene also contains a membrane spanning domain in exon 1 and the motifs NDPNG, partially encoded by mini-exon 2 encoding the tripeptide DPN, and WECVDF (exon 3), which are essential for catalytic activity and are conserved in this gene family5. A key feature identifying it as vacuolar invertase was that the X residue in the conserved WECXDF domain corresponded to a valine residue. This is characteristic of invertases targeted to the vacuole; in the CWIs, X is a proline. | [61-63] |