Abstract
The transcriptional regulation of ADP-glucose pyrophosphorylase (AGPase) genes in detached leaves in response to exogenous sucrose has been investigated earlier; however the effects of endogenous sucrose on AGPase gene transcription in leaves or starch-accumulating tissues have not yet been determined. We therefore have investigated the relationship between endogenous sucrose content in the storage tissues of sweetpotato (Ipomoea batatas cv. Yulmi) and the rate of transcription of the two sweetpotato AGPase isoforms, ibAGP1 and ibAGP2, by means of transient expression analysis of their promoters. Sequence analysis of the two promoters identified putative sucrose-responsive elements on the ibAGP1 promoter and, conversely, putative sucrose-starvation elements on the ibAGP2 promoter. Transient expression analyses on transverse storage root sections revealed that the ibAGP1 and ibAGP2 promoters directed strong expression in the sweetpotato storage roots (diameter: 1.5 cm). Sucrose contents of the sweetpotato storage roots were positively correlated with growth of the storage root. In the storage roots, ibAGP1 promoter activity became stronger with increasing endogenous sucrose levels, while ibAGP2 promoter activity became markedly weaker. Consequently, ibAGP2 was expressed primarily during the early stages of storage root development, whereas ibAGP1 was abundantly expressed in the later stages, during which a profound level of starch accumulation occurs. The antagonistic regulation of the two promoters in response to endogenous sucrose levels was also confirmed in carrot (Daucus carota L. cv. Hapa-ochon) taproots.
| Original language | English |
|---|---|
| Pages (from-to) | 87-96 |
| Number of pages | 10 |
| Journal | Gene |
| Volume | 366 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 2006 Jan 17 |
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Keywords
- β-glucuronidase (GUS)
- AGPase
- Ipomoea batatas
- Transcriptional regulation
- Transient expression
ASJC Scopus subject areas
- Genetics
Cite this
Two sweetpotato ADP-glucose pyrophosphorylase isoforms are regulated antagonistically in response to sucrose content in storage roots. / Kwak, Man Sup; Noh, Seol Ah; Oh, Mi Joung; Huh, Gyung Hye; Kim, Kyung Nam; Lee, Shin Woo; Shin, Jeong Sheop; Bae, Jung Myung.
In: Gene, Vol. 366, No. 1, 17.01.2006, p. 87-96.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Two sweetpotato ADP-glucose pyrophosphorylase isoforms are regulated antagonistically in response to sucrose content in storage roots
AU - Kwak, Man Sup
AU - Noh, Seol Ah
AU - Oh, Mi Joung
AU - Huh, Gyung Hye
AU - Kim, Kyung Nam
AU - Lee, Shin Woo
AU - Shin, Jeong Sheop
AU - Bae, Jung Myung
PY - 2006/1/17
Y1 - 2006/1/17
N2 - The transcriptional regulation of ADP-glucose pyrophosphorylase (AGPase) genes in detached leaves in response to exogenous sucrose has been investigated earlier; however the effects of endogenous sucrose on AGPase gene transcription in leaves or starch-accumulating tissues have not yet been determined. We therefore have investigated the relationship between endogenous sucrose content in the storage tissues of sweetpotato (Ipomoea batatas cv. Yulmi) and the rate of transcription of the two sweetpotato AGPase isoforms, ibAGP1 and ibAGP2, by means of transient expression analysis of their promoters. Sequence analysis of the two promoters identified putative sucrose-responsive elements on the ibAGP1 promoter and, conversely, putative sucrose-starvation elements on the ibAGP2 promoter. Transient expression analyses on transverse storage root sections revealed that the ibAGP1 and ibAGP2 promoters directed strong expression in the sweetpotato storage roots (diameter: 1.5 cm). Sucrose contents of the sweetpotato storage roots were positively correlated with growth of the storage root. In the storage roots, ibAGP1 promoter activity became stronger with increasing endogenous sucrose levels, while ibAGP2 promoter activity became markedly weaker. Consequently, ibAGP2 was expressed primarily during the early stages of storage root development, whereas ibAGP1 was abundantly expressed in the later stages, during which a profound level of starch accumulation occurs. The antagonistic regulation of the two promoters in response to endogenous sucrose levels was also confirmed in carrot (Daucus carota L. cv. Hapa-ochon) taproots.
AB - The transcriptional regulation of ADP-glucose pyrophosphorylase (AGPase) genes in detached leaves in response to exogenous sucrose has been investigated earlier; however the effects of endogenous sucrose on AGPase gene transcription in leaves or starch-accumulating tissues have not yet been determined. We therefore have investigated the relationship between endogenous sucrose content in the storage tissues of sweetpotato (Ipomoea batatas cv. Yulmi) and the rate of transcription of the two sweetpotato AGPase isoforms, ibAGP1 and ibAGP2, by means of transient expression analysis of their promoters. Sequence analysis of the two promoters identified putative sucrose-responsive elements on the ibAGP1 promoter and, conversely, putative sucrose-starvation elements on the ibAGP2 promoter. Transient expression analyses on transverse storage root sections revealed that the ibAGP1 and ibAGP2 promoters directed strong expression in the sweetpotato storage roots (diameter: 1.5 cm). Sucrose contents of the sweetpotato storage roots were positively correlated with growth of the storage root. In the storage roots, ibAGP1 promoter activity became stronger with increasing endogenous sucrose levels, while ibAGP2 promoter activity became markedly weaker. Consequently, ibAGP2 was expressed primarily during the early stages of storage root development, whereas ibAGP1 was abundantly expressed in the later stages, during which a profound level of starch accumulation occurs. The antagonistic regulation of the two promoters in response to endogenous sucrose levels was also confirmed in carrot (Daucus carota L. cv. Hapa-ochon) taproots.
KW - β-glucuronidase (GUS)
KW - AGPase
KW - Ipomoea batatas
KW - Transcriptional regulation
KW - Transient expression
UR - http://www.scopus.com/inward/record.url?scp=32044461352&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=32044461352&partnerID=8YFLogxK
U2 - 10.1016/j.gene.2005.09.021
DO - 10.1016/j.gene.2005.09.021
M3 - Article
C2 - 16338103
AN - SCOPUS:32044461352
VL - 366
SP - 87
EP - 96
JO - Gene
JF - Gene
SN - 0378-1119
IS - 1
ER -