Tags

Type your tag names separated by a space and hit enter

Roles of isoamylase and ADP-glucose pyrophosphorylase in starch granule synthesis in rice endosperm.
Plant J. 2005 Apr; 42(2):164-74.PJ

Abstract

Amyloplast-targeted green fluorescent protein (GFP) was used to monitor amyloplast division and starch granule synthesis in the developing endosperm of transgenic rice. Two classical starch mutants, sugary and shrunken, contain reduced activities of isoamylase1 (ISA1) and cytosolic ADP-glucose pyrophosphorylase, respectively. Dividing amyloplasts in the wild-type and shrunken endosperms contained starch granules, whereas those in sugary endosperm did not contain detectable granules, suggesting that ISA1 plays a role in granule synthesis at the initiation step. The transition from phytoglycogen to sugary-amylopectin was gradual in the boundary region between the inner and outer endosperms of sugary. These results suggest that the synthesis of sugary-amylopectin and phytoglycogen involved a stochastic process and that ISA1 activity plays a critical role in the stochastic process in starch synthesis in rice endosperm. The reduction of cytosolic ADP-glucose pyrophosphorylase activity in shrunken endosperm did not inhibit granule initiation but severely restrained the subsequent enlargement of granules. The shrunken endosperm often developed pleomorphic amyloplasts containing a large number of underdeveloped granules or a large cluster of small grains of amyloplasts, each containing a simple-type starch granule. Although constriction-type divisions of amyloplasts were much more frequent, budding-type divisions were also found in the shrunken endosperm. We show that monitoring GFP in developing amyloplasts was an effective means of evaluating the roles of enzymes involved in starch granule synthesis in the rice endosperm.

Authors+Show Affiliations

Department of Plant Biotechnology, National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba 305 8602, Japan.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

15807780

Citation

Kawagoe, Yasushi, et al. "Roles of Isoamylase and ADP-glucose Pyrophosphorylase in Starch Granule Synthesis in Rice Endosperm." The Plant Journal : for Cell and Molecular Biology, vol. 42, no. 2, 2005, pp. 164-74.
Kawagoe Y, Kubo A, Satoh H, et al. Roles of isoamylase and ADP-glucose pyrophosphorylase in starch granule synthesis in rice endosperm. Plant J. 2005;42(2):164-74.
Kawagoe, Y., Kubo, A., Satoh, H., Takaiwa, F., & Nakamura, Y. (2005). Roles of isoamylase and ADP-glucose pyrophosphorylase in starch granule synthesis in rice endosperm. The Plant Journal : for Cell and Molecular Biology, 42(2), 164-74.
Kawagoe Y, et al. Roles of Isoamylase and ADP-glucose Pyrophosphorylase in Starch Granule Synthesis in Rice Endosperm. Plant J. 2005;42(2):164-74. PubMed PMID: 15807780.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Roles of isoamylase and ADP-glucose pyrophosphorylase in starch granule synthesis in rice endosperm. AU - Kawagoe,Yasushi, AU - Kubo,Akiko, AU - Satoh,Hikaru, AU - Takaiwa,Fumio, AU - Nakamura,Yasunori, PY - 2005/4/6/pubmed PY - 2005/8/9/medline PY - 2005/4/6/entrez SP - 164 EP - 74 JF - The Plant journal : for cell and molecular biology JO - Plant J VL - 42 IS - 2 N2 - Amyloplast-targeted green fluorescent protein (GFP) was used to monitor amyloplast division and starch granule synthesis in the developing endosperm of transgenic rice. Two classical starch mutants, sugary and shrunken, contain reduced activities of isoamylase1 (ISA1) and cytosolic ADP-glucose pyrophosphorylase, respectively. Dividing amyloplasts in the wild-type and shrunken endosperms contained starch granules, whereas those in sugary endosperm did not contain detectable granules, suggesting that ISA1 plays a role in granule synthesis at the initiation step. The transition from phytoglycogen to sugary-amylopectin was gradual in the boundary region between the inner and outer endosperms of sugary. These results suggest that the synthesis of sugary-amylopectin and phytoglycogen involved a stochastic process and that ISA1 activity plays a critical role in the stochastic process in starch synthesis in rice endosperm. The reduction of cytosolic ADP-glucose pyrophosphorylase activity in shrunken endosperm did not inhibit granule initiation but severely restrained the subsequent enlargement of granules. The shrunken endosperm often developed pleomorphic amyloplasts containing a large number of underdeveloped granules or a large cluster of small grains of amyloplasts, each containing a simple-type starch granule. Although constriction-type divisions of amyloplasts were much more frequent, budding-type divisions were also found in the shrunken endosperm. We show that monitoring GFP in developing amyloplasts was an effective means of evaluating the roles of enzymes involved in starch granule synthesis in the rice endosperm. SN - 0960-7412 UR - https://www.unboundmedicine.com/medline/citation/15807780/Roles_of_isoamylase_and_ADP_glucose_pyrophosphorylase_in_starch_granule_synthesis_in_rice_endosperm_ DB - PRIME DP - Unbound Medicine ER -