Presence of Multiple cDNAs Encoding an Isoform of ADP-Glucose Pyrophosphorylase Large Subunit from Sweet Potato and Characterization of Expression Levels

Cited 29 time in scopus
Metadata Downloads
Title
Presence of Multiple cDNAs Encoding an Isoform of ADP-Glucose Pyrophosphorylase Large Subunit from Sweet Potato and Characterization of Expression Levels
Author(s)
Chee Hark Harn; Jung Myung Bae; Sang Sook Lee; Sung Ran Min; Jang Ryol Liu
Bibliographic Citation
Plant and Cell Physiology, vol. 41, no. 11, pp. 1235-1242
Publication Year
2000
Abstract
Three cDNAs (iAGPLI-1, iAGPLI-2, and iAGPLI-3) encoding an isoform of AGPase large subunit were isolated from a sweet potato cDNA library constructed from tuberous root tissue. iAGPLI-1 was 2,161 bp in length and contained an open reading frame of 517 amino acids with a calculated molecular mass of 57,689 Da. iAGPLI-2 and iAGPLI-3 were 1,804 and 1,524 bp in length, respectively, and contained partial open reading frames of 490 and 385 amino acids. Deduced amino acid sequence comparison analysis showed that iAGPLI-1 has sequence identity with iAGPLI-2 (97.9) and iAGPLI-3 (98.7%) while iAGPLI-2 and iAGPLI-3 have 96.8% sequence identity, iAGPLI-1 had the highest sequence identity of 77.8% with potato AGPase (sAGPL1). Steady-state levels of iAGPLI-1 transcripts were expressed predominantly in the stem, and moderately in the tuberous root, but not in either the roots or leaves. However, AGPase activity was present in all tissues. The expression level in the stem declined dramatically after a 12 h incubation in the dark to nearly 3% of the value under light, although the activity under a dark condition remained at half the levels in light. The activity levels were not correlated with the transcript levels. iAGPL transcripts in leaves were induced by sucrose feeding but not by glucose or fructose. Therefore, the expression of iAGPLI-1 is regulated in stem tissue preferentially and by sucrose. Southern blot analysis showed that the sweet potato genome contained several copies of iAGPLI gene probably due to polyploidy.
Keyword
ADP-glucose pyrophosphorylase large subunitAGPase activitysweet potatostarch biosynthesis
ISSN
0032-0781
Publisher
Oxford Univ Press
DOI
http://dx.doi.org/10.1093/pcp/pcd049
Type
Article
Appears in Collections:
Division of Research on National Challenges > Plant Systems Engineering Research > 1. Journal Articles
Files in This Item:
  • There are no files associated with this item.


Items in OpenAccess@KRIBB are protected by copyright, with all rights reserved, unless otherwise indicated.