| Nonsymbiotic hemoglobin-2 leads to an elevated energy state and to a combined increase in polyunsaturated fatty acids and total oil content when overexpressed in developing seeds of transgenic Arabidopsis plants. | |
| | |
MedLine Citation:
|
PMID: 21205621 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
Nonsymbiotic hemoglobins are ubiquitously expressed in plants and divided into two different classes based on gene expression pattern and oxygen-binding properties. Most of the published research has been on the function of class 1 hemoglobins. To investigate the role of class 2 hemoglobins, transgenic Arabidopsis (Arabidopsis thaliana) plants were generated overexpressing Arabidopsis hemoglobin-2 (AHb2) under the control of a seed-specific promoter. Overexpression of AHb2 led to a 40% increase in the total fatty acid content of developing and mature seeds in three subsequent generations. This was mainly due to an increase in the polyunsaturated C18:2 (ω-6) linoleic and C18:3 (ω-3) α-linolenic acids. Moreover, AHb2 overexpression led to an increase in the C18:2/C18:1 and C18:3/C18:2 ratios as well as in the C18:3 content in mol % of total fatty acids and in the unsaturation/saturation index of total seed lipids. The increase in fatty acid content was mainly due to a stimulation of the rate of triacylglycerol synthesis, which was attributable to a 3-fold higher energy state and a 2-fold higher sucrose content of the seeds. Under low external oxygen, AHb2 overexpression maintained an up to 5-fold higher energy state and prevented fermentation. This is consistent with AHb2 overexpression results in improved oxygen availability within developing seeds. In contrast to this, overexpression of class 1 hemoglobin did not lead to any significant increase in the metabolic performance of the seeds. These results provide evidence for a specific function of class 2 hemoglobin in seed oil production and in promoting the accumulation of polyunsaturated fatty acids by facilitating oxygen supply in developing seeds. |
| | |
Authors:
|
Helene Vigeolas; Daniela Hühn; Peter Geigenberger |
Publication Detail:
|
Type: Journal Article; Research Support, Non-U.S. Gov't Date: 2011-01-03 |
Journal Detail:
|
Title: Plant physiology Volume: 155 ISSN: 1532-2548 ISO Abbreviation: Plant Physiol. Publication Date: 2011 Mar |
Date Detail:
|
Created Date: 2011-03-02 Completed Date: 2011-05-31 Revised Date: 2011-08-29 |
Medline Journal Info:
|
Nlm Unique ID: 0401224 Medline TA: Plant Physiol Country: United States |
Other Details:
|
Languages: eng Pagination: 1435-44 Citation Subset: IM |
Affiliation:
|
Genetics of Microorganisms, Department of Life Sciences, Institute of Botany, University of Liege, 4000 Liege, Belgium. |
| Data Bank Information | |
Bank Name/Acc. No.:
|
RefSeq/NM_111887; NM_127165 |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Arabidopsis
/
drug effects,
embryology*,
genetics,
metabolism Arabidopsis Proteins / metabolism* Energy Metabolism* / drug effects Fatty Acids, Unsaturated / metabolism* Fermentation / drug effects Hemoglobins / metabolism* Organ Specificity / drug effects, genetics Oxygen / pharmacology Plant Oils / metabolism* Plants, Genetically Modified Promoter Regions, Genetic / genetics Seeds / drug effects, embryology, genetics, metabolism* Sucrose / metabolism Symbiosis* / drug effects Triglycerides / metabolism alpha-Linolenic Acid / metabolism |
| Chemical | |
Reg. No./Substance:
|
0/AHB1 protein, Arabidopsis; 0/AHB2 protein, Arabidopsis; 0/Arabidopsis Proteins; 0/Fatty Acids, Unsaturated; 0/Hemoglobins; 0/Plant Oils; 0/Triglycerides; 463-40-1/alpha-Linolenic Acid; 57-50-1/Sucrose; 7782-44-7/Oxygen |
| Comments/Corrections | |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Red clover HCT2, a hydroxycinnamoyl-coenzyme A:malate hydroxycinnamoyl transferase, plays a crucial ...
Next Document: Combining enhanced root and shoot growth reveals cross talk between pathways that control plant orga...