Essential amino acids of starch synthase IIa differentiate amylopectin structure and starch quality between japonica and indica rice varieties

Essential amino acids of starch synthase IIa differentiate amylopectin structure and starch... Four amino acids were variable between the ‘active’ indica-type and ‘inactive’ japonica-type soluble starch synthase Ha (SSIIa) of rice plants; Glu-88 and Gly-604 in SSIIa of indica-cultivars IR36 and Kasalath were replaced by Asp-88 and Ser-604, respectively, in both japonica cultivars Nipponbare and Kinmaze SSIIa, whereas Val-737 and Leu-781 in indica SSIIa were replaced by Met-737 in cv. Nipponbare and Phe-781 in cv. Kinmaze SSIIa, respectively. The SSIIa gene fragments shuffling experiments revealed that Val-737 and Leu-781 are essential not only for the optimal SSIIa activity, but also for the capacity to synthesize indica-type amylopectin. Surprisingly, however, a combination of Phe-781 and Gly-604 could restore about 44% of the SSIIa activity provided that Val-737 was conserved. The introduction of the ‘active’ indica-type SSIIa gene enabled the japonica-type cv. Kinmaze to synthesize indica-type amylopectin. The starch in the transformed japonica rice plants exhibited gelatinization-resistant properties that are characteristic of indica-rice starch. Transformed lines expressing different levels of the IR36 SSIIa protein produced a variety of starches with amylopectin chain-length distribution patterns that correlated well with their onset temperatures of gelatinization. The present study confirmed that the SSIIa activity determines the type of amylopectin structure of rice starch to be either the typical indica-type or japonica-type, by playing a specific role in the synthesis of the long B1 chains by elongating short A and B1 chains, notwithstanding the presence of functional two additional SSII genes, a single SSI gene, two SSIII genes, and two SSIV genes in rice plants. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Plant Molecular Biology Springer Journals

Essential amino acids of starch synthase IIa differentiate amylopectin structure and starch quality between japonica and indica rice varieties

Loading next page...
 
/lp/springer_journal/essential-amino-acids-of-starch-synthase-iia-differentiate-amylopectin-hKflJdr7OZ
Publisher
Springer Netherlands
Copyright
Copyright © 2005 by Springer
Subject
Life Sciences; Plant Sciences; Biochemistry, general; Plant Pathology
ISSN
0167-4412
eISSN
1573-5028
D.O.I.
10.1007/s11103-005-6507-2
Publisher site
See Article on Publisher Site

Abstract

Four amino acids were variable between the ‘active’ indica-type and ‘inactive’ japonica-type soluble starch synthase Ha (SSIIa) of rice plants; Glu-88 and Gly-604 in SSIIa of indica-cultivars IR36 and Kasalath were replaced by Asp-88 and Ser-604, respectively, in both japonica cultivars Nipponbare and Kinmaze SSIIa, whereas Val-737 and Leu-781 in indica SSIIa were replaced by Met-737 in cv. Nipponbare and Phe-781 in cv. Kinmaze SSIIa, respectively. The SSIIa gene fragments shuffling experiments revealed that Val-737 and Leu-781 are essential not only for the optimal SSIIa activity, but also for the capacity to synthesize indica-type amylopectin. Surprisingly, however, a combination of Phe-781 and Gly-604 could restore about 44% of the SSIIa activity provided that Val-737 was conserved. The introduction of the ‘active’ indica-type SSIIa gene enabled the japonica-type cv. Kinmaze to synthesize indica-type amylopectin. The starch in the transformed japonica rice plants exhibited gelatinization-resistant properties that are characteristic of indica-rice starch. Transformed lines expressing different levels of the IR36 SSIIa protein produced a variety of starches with amylopectin chain-length distribution patterns that correlated well with their onset temperatures of gelatinization. The present study confirmed that the SSIIa activity determines the type of amylopectin structure of rice starch to be either the typical indica-type or japonica-type, by playing a specific role in the synthesis of the long B1 chains by elongating short A and B1 chains, notwithstanding the presence of functional two additional SSII genes, a single SSI gene, two SSIII genes, and two SSIV genes in rice plants.

Journal

Plant Molecular BiologySpringer Journals

Published: Mar 23, 2005

References

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Search

Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly

Organize

Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.

Access

Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

DeepDyve

Freelancer

DeepDyve

Pro

Price

FREE

$49/month
$360/year

Save searches from
Google Scholar,
PubMed

Create lists to
organize your research

Export lists, citations

Read DeepDyve articles

Abstract access only

Unlimited access to over
18 million full-text articles

Print

20 pages / month

PDF Discount

20% off