Plant Physiology Preview Published on April 9, 2002; 10.1104/pp.010747
Received August 16, 2001
Returned for revision November 7, 2001
Accepted January 24, 2002
Isolation and Characterization of Homogentisate Phytyltransferase
Genes from Synechocystis sp. PCC 6803 and
Arabidopsis
Beth Savidge , James D. Weiss , Yun-Hua H. Wong , Michael W. Lassner , Timothy A. Mitsky , Christine K. Shewmaker , Dusty Post-Beittenmiller , and Henry E. Valentin *
Monsanto Company, Calgene Campus, 1920 Fifth Street, Davis, California 95616 (B.S., M.W.L., C.K.S.); and Monsanto Company, 800 N. Lindbergh Boulevard, St. Louis, Missouri 63167 (J.D.W., Y.-H.H.W., T.A.M., D.P.-B., H.E.V.)
* Corresponding author; email: henry.e.valentin{at}monsanto.com.
Tocopherols, synthesized by photosynthetic organisms, are micronutrients with antioxidant properties that play important roles in animal and human nutrition. Because of these health benefits, there is considerable interest in identifying the genes involved in tocopherol biosynthesis to allow transgenic alteration of both tocopherol levels and composition in agricultural crops. Tocopherols are generated from the condensation of phytyldiphosphate and homogentisic acid (HGA), followed by cyclization and methylation reactions. Homogentisate phytyltransferase (HPT) performs the first committed step in this pathway, the phytylation of HGA. In this study, bioinformatics techniques were used to identify candidate genes, slr1736 and HPT1, that encode HPT from Synechocystis sp. PCC 6803 and Arabidopsis, respectively. These two genes encode putative membrane-bound proteins, and contain amino acid residues highly conserved with other prenyltransferases of the aromatic type. A Synechocystis sp. PCC 6803 slr1736 null mutant obtained by insertional inactivation did not accumulate tocopherols, and was rescued by the Arabidopsis HPT1 ortholog. The membrane fraction of wild-type Synechocystis sp. PCC 6803 was capable of catalyzing the phytylation of HGA, whereas the membrane fraction from the slr1736 null mutant was not. The microsomal membrane fraction of baculovirus-infected insect cells expressing the Synechocystis sp. PCC 6803 slr1736 were also able to perform the phytylation reaction, verifying HPT activity of the protein encoded by this gene. In addition, evidence that antisense expression of HPT1 in Arabidopsis resulted in reduced seed tocopherol levels, whereas seed-specific sense expression resulted in increased seed tocopherol levels, is presented.
This article has been cited by other articles:

|
 |

|
 |
 
T. E. Clemente and E. B. Cahoon
Soybean Oil: Genetic Approaches for Modification of Functionality and Total Content
Plant Physiology,
November 1, 2009;
151(3):
1030 - 1040.
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
Y. Yang, C. Yin, W. Li, and X. Xu
{alpha}-Tocopherol Is Essential for Acquired Chill-Light Tolerance in the Cyanobacterium Synechocystis sp. Strain PCC 6803
J. Bacteriol.,
March 1, 2008;
190(5):
1554 - 1560.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
K. Sasaki, K. Mito, K. Ohara, H. Yamamoto, and K. Yazaki
Cloning and Characterization of Naringenin 8-Prenyltransferase, a Flavonoid-Specific Prenyltransferase of Sophora flavescens
Plant Physiology,
March 1, 2008;
146(3):
1075 - 1084.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
H. Maeda, T. L. Sage, G. Isaac, R. Welti, and D. DellaPenna
Tocopherols Modulate Extraplastidic Polyunsaturated Fatty Acid Metabolism in Arabidopsis at Low Temperature
PLANT CELL,
February 1, 2008;
20(2):
452 - 470.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
H. E. Valentin, K. Lincoln, F. Moshiri, P. K. Jensen, Q. Qi, T. V. Venkatesh, B. Karunanandaa, S. R. Baszis, S. R. Norris, B. Savidge, et al.
The Arabidopsis vitamin E pathway gene5-1 Mutant Reveals a Critical Role for Phytol Kinase in Seed Tocopherol Biosynthesis
PLANT CELL,
January 1, 2006;
18(1):
212 - 224.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
Q. Qi, M. Hao, W.-o. Ng, S. C. Slater, S. R. Baszis, J. D. Weiss, and H. E. Valentin
Application of the Synechococcus nirA Promoter To Establish an Inducible Expression System for Engineering the Synechocystis Tocopherol Pathway
Appl. Envir. Microbiol.,
October 1, 2005;
71(10):
5678 - 5684.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
M. Kanwischer, S. Porfirova, E. Bergmuller, and P. Dormann
Alterations in Tocopherol Cyclase Activity in Transgenic and Mutant Plants of Arabidopsis Affect Tocopherol Content, Tocopherol Composition, and Oxidative Stress
Plant Physiology,
February 1, 2005;
137(2):
713 - 723.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
D. Hofius, M.-R. Hajirezaei, M. Geiger, H. Tschiersch, M. Melzer, and U. Sonnewald
RNAi-Mediated Tocopherol Deficiency Impairs Photoassimilate Export in Transgenic Potato Plants
Plant Physiology,
July 1, 2004;
135(3):
1256 - 1268.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
S. E. Sattler, L. U. Gilliland, M. Magallanes-Lundback, M. Pollard, and D. DellaPenna
Vitamin E Is Essential for Seed Longevity and for Preventing Lipid Peroxidation during Germination
PLANT CELL,
June 1, 2004;
16(6):
1419 - 1432.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
P. Rippert, C. Scimemi, M. Dubald, and M. Matringe
Engineering Plant Shikimate Pathway for Production of Tocotrienol and Improving Herbicide Resistance
Plant Physiology,
January 1, 2004;
134(1):
92 - 100.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
A. L. Van Eenennaam, K. Lincoln, T. P. Durrett, H. E. Valentin, C. K. Shewmaker, G. M. Thorne, J. Jiang, S. R. Baszis, C. K. Levering, E. D. Aasen, et al.
Engineering Vitamin E Content: From Arabidopsis Mutant to Soy Oil
PLANT CELL,
December 1, 2003;
15(12):
3007 - 3019.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
Z. Cheng, S. Sattler, H. Maeda, Y. Sakuragi, D. A. Bryant, and D. DellaPenna
Highly Divergent Methyltransferases Catalyze a Conserved Reaction in Tocopherol and Plastoquinone Synthesis in Cyanobacteria and Photosynthetic Eukaryotes
PLANT CELL,
October 1, 2003;
15(10):
2343 - 2356.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
E. Collakova and D. DellaPenna
The Role of Homogentisate Phytyltransferase and Other Tocopherol Pathway Enzymes in the Regulation of Tocopherol Synthesis during Abiotic Stress
Plant Physiology,
October 1, 2003;
133(2):
930 - 940.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
S. E. Sattler, E. B. Cahoon, S. J. Coughlan, and D. DellaPenna
Characterization of Tocopherol Cyclases from Higher Plants and Cyanobacteria. Evolutionary Implications for Tocopherol Synthesis and Function
Plant Physiology,
August 1, 2003;
132(4):
2184 - 2195.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
E. Collakova and D. DellaPenna
Homogentisate Phytyltransferase Activity Is Limiting for Tocopherol Biosynthesis in Arabidopsis
Plant Physiology,
February 1, 2003;
131(2):
632 - 642.
[Abstract]
[Full Text]
[PDF]
|
 |
|
|
|