First published online January 9, 2003; 10.1104/pp.013094
Plant Physiol, February 2003, Vol. 131, pp. 684-696
A Low-Starch Barley Mutant, Risø 16, Lacking the Cytosolic Small
Subunit of ADP-Glucose Pyrophosphorylase, Reveals the Importance of the
Cytosolic Isoform and the Identity of the Plastidial Small
Subunit1
Philip E.
Johnson,2
Nicola J.
Patron,2
Andrew R.
Bottrill,
Jason R.
Dinges,
Brendan F.
Fahy,
Mary L.
Parker,
Darren N.
Waite, and
Kay
Denyer*
John Innes Centre, Norwich Research Park, Colney, Norfolk NR4 7UH,
United Kingdom (P.E.J., N.J.P., A.R.B., B.F.F., D.N.W., K.D.);
Department of Zoology and Genetics, Iowa State University, Ames, Iowa
50011 (J.R.D.); and Institute of Food Research, Norwich Research Park,
Colney, Norfolk NR4 7UA, United Kingdom (M.L.P.)
To provide information on the roles of the different
forms of ADP-glucose pyrophosphorylase (AGPase) in barley
(Hordeum vulgare) endosperm and the nature of the genes
encoding their subunits, a mutant of barley, Risø 16, lacking
cytosolic AGPase activity in the endosperm was identified. The mutation
specifically abolishes the small subunit of the cytosolic AGPase and is
attributable to a large deletion within the coding region of a
previously characterized small subunit gene that we have called
Hv.AGP.S.1. The plastidial AGPase activity in the mutant is unaffected.
This shows that the cytosolic and plastidial small subunits of AGPase
are encoded by separate genes. We purified the plastidial AGPase
protein and, using amino acid sequence information, we identified the
novel small subunit gene that encodes this protein. Studies of the
Risø 16 mutant revealed the following. First, the reduced starch
content of the mutant showed that a cytosolic AGPase is required to
achieve the normal rate of starch synthesis. Second, the mutant makes both A- and B-type starch granules, showing that the cytosolic AGPase
is not necessary for the synthesis of these two granule types. Third,
analysis of the phylogenetic relationships between the various small
subunit proteins both within and between species, suggest that the
cytosolic AGPase single small subunit gene probably evolved from a leaf
single small subunit gene.
1
This work was supported by the Biotechnology and
Biological Sciences Research Council (UK; competitive strategic grant
to the John Innes Centre), by DuPont Agricultural Products (Newark, DE), and by the Iowa State University College of Agriculture (Ames; international travel award to J.R.D.).
2
These authors contributed equally to the paper.
*
Corresponding author; e-mail kay.denyer{at}bbsrc.ac.uk; fax
44-1603-450045.
© 2003 American Society of Plant Biologists
This article has been cited by other articles:
|
|
|
|
 
M. T. Hamblin, M. G. Salas Fernandez, M. R. Tuinstra, W. L. Rooney, and S. Kresovich
Sequence Variation at Candidate Loci in the Starch Metabolism Pathway in Sorghum: Prospects for Linkage Disequilibrium Mapping
Crop Sci.,
July 16, 2007;
47(S2):
S-125 - S-134.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
N. Georgelis, E. L. Braun, J. R. Shaw, and L. C. Hannah
The Two AGPase Subunits Evolve at Different Rates in Angiosperms, yet They Are Equally Sensitive to Activity-Altering Amino Acid Changes When Expressed in Bacteria
PLANT CELL,
May 1, 2007;
19(5):
1458 - 1472.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. Rosti, H. Rudi, K. Rudi, H.-G. Opsahl-Sorteberg, B. Fahy, and K. Denyer
The gene encoding the cytosolic small subunit of ADP-glucose pyrophosphorylase in barley endosperm also encodes the major plastidial small subunit in the leaves
J. Exp. Bot.,
November 1, 2006;
57(14):
3619 - 3626.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
T. Ohdan, P. B. Francisco Jr, T. Sawada, T. Hirose, T. Terao, H. Satoh, and Y. Nakamura
Expression profiling of genes involved in starch synthesis in sink and source organs of rice
J. Exp. Bot.,
December 1, 2005;
56(422):
3229 - 3244.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
T. Akihiro, K. Mizuno, and T. Fujimura
Gene Expression of ADP-glucose Pyrophosphorylase and Starch Contents in Rice Cultured Cells are Cooperatively Regulated by Sucrose and ABA
Plant Cell Physiol.,
June 1, 2005;
46(6):
937 - 946.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
W. Dian, H. Jiang, and P. Wu
Evolution and expression analysis of starch synthase III and IV in rice
J. Exp. Bot.,
February 1, 2005;
56(412):
623 - 632.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
N. J. Patron, B. Greber, B. F. Fahy, D. A. Laurie, M. L. Parker, and K. Denyer
The lys5 Mutations of Barley Reveal the Nature and Importance of Plastidial ADP-Glc Transporters for Starch Synthesis in Cereal Endosperm
Plant Physiology,
August 1, 2004;
135(4):
2088 - 2097.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J. M. Cross, M. Clancy, J. R. Shaw, T. W. Greene, R. R. Schmidt, T. W. Okita, and L. C. Hannah
Both Subunits of ADP-Glucose Pyrophosphorylase Are Regulatory
Plant Physiology,
May 1, 2004;
135(1):
137 - 144.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
