Document Detail

Light intensity-dependent modulation of chlorophyll b biosynthesis and photosynthesis by overexpression of chlorophyllide a oxygenase in tobacco.
MedLine Citation:
PMID:  22419827     Owner:  NLM     Status:  MEDLINE    
Chlorophyll b is synthesized by the oxidation of a methyl group on the B ring of a tetrapyrrole molecule to a formyl group by chlorophyllide a oxygenase (CAO). The full-length CAO from Arabidopsis (Arabidopsis thaliana) was overexpressed in tobacco (Nicotiana tabacum) that grows well at light intensities much higher than those tolerated by Arabidopsis. This resulted in an increased synthesis of glutamate semialdehyde, 5-aminolevulinic acid, magnesium-porphyrins, and chlorophylls. Overexpression of CAO resulted in increased chlorophyll b synthesis and a decreased chlorophyll a/b ratio in low light-grown as well as high light-grown tobacco plants; this effect, however, was more pronounced in high light. The increased potential of the protochlorophyllide oxidoreductase activity and chlorophyll biosynthesis compensated for the usual loss of chlorophylls in high light. Increased chlorophyll b synthesis in CAO-overexpressed plants was accompanied not only by an increased abundance of light-harvesting chlorophyll proteins but also of other proteins of the electron transport chain, which led to an increase in the capture of light as well as enhanced (40%-80%) electron transport rates of photosystems I and II at both limiting and saturating light intensities. Although the quantum yield of carbon dioxide fixation remained unchanged, the light-saturated photosynthetic carbon assimilation, starch content, and dry matter accumulation increased in CAO-overexpressed plants grown in both low- and high-light regimes. These results demonstrate that controlled up-regulation of chlorophyll b biosynthesis comodulates the expression of several thylakoid membrane proteins that increase both the antenna size and the electron transport rates and enhance carbon dioxide assimilation, starch content, and dry matter accumulation.
Ajaya K Biswal; Gopal K Pattanayak; Shiv S Pandey; Sadhu Leelavathi; Vanga S Reddy; Govindjee; Baishnab C Tripathy
Related Documents :
7092707 - The influence of the effect system on adaptation, temporary and permanent threshold shift.
12003167 - Bright light exposure at night and light attenuation in the morning improve adaptation ...
7369977 - Identification of the minimum noise level capable of producing an asymptotic temporary ...
21596047 - Testosterone and 11-ketotestosterone have different regulatory effects on electric comm...
1232917 - Lateral facilitation of hoffmann-reflexes prior to voluntary movement in a choice react...
8208737 - Daily exposure to a nonphotic stimulus can alter photoperiodic response to short days i...
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2012-03-14
Journal Detail:
Title:  Plant physiology     Volume:  159     ISSN:  1532-2548     ISO Abbreviation:  Plant Physiol.     Publication Date:  2012 May 
Date Detail:
Created Date:  2012-05-04     Completed Date:  2012-08-23     Revised Date:  2013-06-26    
Medline Journal Info:
Nlm Unique ID:  0401224     Medline TA:  Plant Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  433-49     Citation Subset:  IM    
School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Aminolevulinic Acid / metabolism
Arabidopsis / genetics,  metabolism
Carbon Dioxide / metabolism
Chlorophyll / biosynthesis*
Electron Transport
Enzyme Activation
Gene Expression Regulation, Plant
Genes, Plant
Oxygenases / genetics,  metabolism*
Photosystem I Protein Complex / genetics,  metabolism
Photosystem II Protein Complex / genetics,  metabolism
Plant Leaves / enzymology,  genetics,  radiation effects
Plant Proteins / genetics,  metabolism
Plants, Genetically Modified / enzymology,  genetics,  radiation effects
Starch / metabolism
Thylakoid Membrane Proteins / genetics,  metabolism
Tobacco / enzymology*,  genetics,  radiation effects
Reg. No./Substance:
0/Photosystem I Protein Complex; 0/Photosystem II Protein Complex; 0/Plant Proteins; 0/Thylakoid Membrane Proteins; 106-60-5/Aminolevulinic Acid; 124-38-9/Carbon Dioxide; 1406-65-1/Chlorophyll; 5712ZB110R/chlorophyll b; 9005-25-8/Starch; EC 1.13.-/Oxygenases; EC 1.13.12.-/chlorophyll a oxygenase

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  The Arabidopsis microRNA396-GRF1/GRF3 regulatory module acts as a developmental regulator in the rep...
Next Document:  A salt-bridge controlled by ligand binding modulates the hydrolysis reaction in a GH5 endoglucanase.