ELUCIDATING THE GENETIC ARCHITECTURE OF ESSENTIAL MICRONUTRIENT ACCUMULATION IN SEED

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 0187104
• Project Start Date: Oct 1, 2010
• Project End Date: Sep 30, 2015
• Program Code: [(N/A)]- (N/A)

Recipient Organization
MICHIGAN STATE UNIV
(N/A)
EAST LANSING,MI 48824

Performing Department
Biochemistry & Molecular Biology

Non Technical Summary
Specific carotenoids (β-carotene, α-carotene and β-cryptoxanthin) and tocochromanols in plant-based foods are dietary sources of provitamin A and vitamin E 1-3, respectively, and are required at minimum daily levels in the diet of humans and animals for optimal health. Animal feed and processed food for humans are routinely fortified with vitamins and minerals in developed (but not developing) countries. While the vitamin A requirement in the US is largely met through fortification, surprisingly large proportions of the US population still do not obtain the daily-recommended amount of vitamin E in their diet, with deficient intake being as high as 90% in some population segments (e.g. the elderly) 4-6. Carotenoids and tocochromanols are also antioxidants and provide a range of additional health benefits related to vision, heart disease and specific cancers 7-11. For example, elevated levels of dietary lutein and zeaxanthin12,13 are associated with a decreased rate and delayed onset of age-related macular degeneration (AMD), likely because they quench free radicals and attenuate blue light intensity, reducing oxidative stress to the retina 14. Thus, understanding and manipulating the levels of specific essential nutrients like carotenoids and tocochromanols in plants will allow a direct means for affecting the levels of these compounds in the food supply to positively impact populations, both in developed and developing countries.

Animal Health Component

(N/A)

Research Effort Categories

Basic

(N/A)

Applied

(N/A)

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
201	2499	1010	80%
201	1510	1010	20%

Knowledge Area
201 - Plant Genome, Genetics, and Genetic Mechanisms;

Subject Of Investigation
1510 - Corn; 2499 - Plant research, general;

Field Of Science
1010 - Nutrition and metabolism;

Keywords

association mapping

vitamins

essential amino acids

arabidopsis

maize

Goals / Objectives
Plant based food is the basis of the human food and animal feed supply and while crops can readily provide adequate macronutrients (carbohydrates, proteins and lipids) for energy production, the edible portions of all major food and feed crops are deficient in multiple micronutrients (vitamins, minerals, essential amino acids). Therefore, reliance on major crops for the foundation of one's diet leads to severe micronutrient deficiency and as a result plant derived foods must be fortified with micronutrients. Carotenoids and tocochromanols (tocopherols and tocotrienols) in plant-based foods are dietary sources of provitamin A and vitamin E and are required at minimum daily levels for optimal health in human and animal diets. My group has been studying the synthesis and accumulation of these two compounds as models for understanding micronutrients in plants. To enhance our knowledge of the polygenic nature of these compounds in agricultural seeds, and to provide the basis for expanding our research to include other water soluble vitamins and essential amino acids in plant based foods, we plan to transfer and leverage information involving fundamental biological aspects of biosynthesis of these compounds from the model system Arabidopsis to the economically important crop maize.

Project Methods
Using data from Arabidopsis, we will identify orthologs for carotenoid and tocopherol biosynthetic pathways in the maize genome. Whole genome and candidate gene association studies in both maize and Arabidopsis will be used to identify novel genes, functional variant alleles, and the genetic architecture of micronutrient traits. Genetic mapping data will be integrated with developing seed expression data obtained using next generation whole transcriptome sequencing to delineate potential candidate genes responsible for traits. Not only will this enable a comparative analysis of the genetic architecture of these traits between Arabidopsis, a dicot, selfing species with maize, a monocot, outcrossing species, but it will also be directly useful for improving vitamin content in crops through on-going breeding programs.

Progress 10/01/10 to 09/30/15

Outputs
Target Audience:Fellow scientists including Principle investigators, postdoctoral researchers, technicians, graduate students and undergraduate students. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? As in past years, the research program continues to provide an ideal environment for interdisciplinary training of postdoctoral researchers and graduate students at the interface of plant quantitative genetics, plant genomics, plant biochemistry and breeding. Students and postdocs participate in an annual project meeting with all members from the participating institutions and attend one scientific meeting per year in this area of research. How have the results been disseminated to communities of interest? The most relevant communities continue to have the results of this work disseminated in the form of publications and verbally through seminars and other speaking venues by the PI and the PI and other members of the laboratory when they attend and present posters or talks describing progress and work to date. The PI presented results of these studies at four scientific meetings/seminars in 2014 and 2015. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? The long term goal of the proposed research is to further our understanding of the biosynthesis and function of essential micronutrients in plants such that a sound scientific basis for the manipulation of their levels in crops, and improvement of global human health, can be undertaken. To enhance our knowledge of the polygenic nature of these compounds in agricultural seeds, and to provide the basis for expanding our research to include other water soluble vitamins and essential amino acids in plant based foods, we have transferred and leverage dinformation involving fundamental biological aspects of biosynthesis of these compounds from the model system Arabidopsis to the economically important crop maize. Using data from Arabidopsis, we have identified orthologs for carotenoid (pro and non-pro vitamin A) and tocopherol (vitamin E) biosynthetic pathways in the maize genome. Whole genome and candidate gene association studies in both maize and Arabidopsis have identified which pathway genes and their functional variant alleles impact the target traits. Nested association mapping has revealed the genetic architecture for these traits in maize and shown that vitamin E has a much larger number of novel loci involved that are clearly not the already characterized pathway genes.

Publications

• Type: Journal Articles Status: Published Year Published: 2014 Citation: Owens, B. F., Lipka, A. E., Magallanes-Lundback, M., Tiede, T., Diepenbrock, C. H., Kandianis, C. B., Kim, E.H., Cepela, J., Mateos-Hernandez, M., Buell, C.R., Buckler, E.S., DellaPenna, D., Gore, M.A., Rocheford, T. (2014). A foundation for provitamin a biofortification of maize: genome-wide association and genomic prediction models of carotenoid levels. Genetics, 198(4), 16991716.
• Type: Journal Articles Status: Published Year Published: 2014 Citation: Hiroshi Maeda, Wan Song, Tammy Sage, Dean DellaPenna (2014) Role of callose synthases in transfer cell wall development in tocopherol deficient Arabidopsis mutants. Frontiers in Plant Sciences. February 2014 | doi: 10.3389/fpls.2014.00046

Progress 10/01/13 to 09/30/14

Outputs
Target Audience: Breeders, Plant biochemists, Plant geneticists, Nutritional scientists. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? The research program provides an ideal environment for interdisciplinary training of postdoctoral researchers and graduate students at the interface of plant quantitative genetics, plant genomics, plant biochemistry and breeding. Students and postdocs participate in an annual project meeting with all members from the participating institutions and attend one scientific meeting per year in this area of research. How have the results been disseminated to communities of interest? The most relevant communities have the results of this work disseminated in the form of publications and verbally through seminars and other speaking venues by the PI and the PI and other members of the laboratory when they attend and present posters or talks describing progress and work to date. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? The long term goal of the proposed research is to further our understanding of the biosynthesis and function of essential micronutrients in plants such that a sound scientific basis for the manipulation of their levels in crops, and improvement of global human health, can be undertaken. To enhance our knowledge of the polygenic nature of these compounds in agricultural seeds, and to provide the basis for expanding our research to include other water soluble vitamins and essential amino acids in plant based foods, we have transferred and leverage dinformation involving fundamental biological aspects of biosynthesis of these compounds from the model system Arabidopsis to the economically important crop maize. Using data from Arabidopsis, we have identified orthologs for carotenoid (pro and non-pro vitamin A) and tocopherol (vitamin E) biosynthetic pathways in the maize genome. Whole genome and candidate gene association studies in both maize and Arabidopsis have identified which pathway genes and their functional variant alleles impact the target traits. Nested association mapping has revealed the genetic architecture for the traits in maize and shown that vitamin E has a much larger number of novel loci involved that are clearly not the already characterized pathway genes. We have generated whole transcriptome expression profiles across seed development to help delineate potential candidate genes responsible for traits. Not only will this enable a comparative analysis of the genetic architecture of these traits between Arabidopsis, a dicot, selting species with maize, a monocot, outcrossing species, but it will also be directly useful for improving vitamin content in crops

Publications

• Type: Journal Articles Status: Published Year Published: 2013 Citation: A and DellaPenna D. (2013) CAROTENOID CLEAVAGE DIOXYGENASE 4 is a Negative Regulator of beta-carotene content in Arabidopsis Seed. The Plant Cell. 25:4812-4826.
• Type: Journal Articles Status: Published Year Published: 2013 Citation: Angelovici R, Lipka AE, Deason N, GonzalezJorge S, Lin H, Cepela J, Buell CR, Gore MA and DellaPenna D. (2013) Genome-wide analysis of branched-chain amino acid levels in Arabidopsis seed. The Plant Cell. 25:4827-4843.

Progress 01/01/13 to 09/30/13

Outputs
Target Audience: Breeders, Plant biochemists, Plant geneticists, nutritional scientists Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? The research program provides an ideal environment for interdisciplinary training of postdoctoral researchers and graduate students at the interface of plant quantitative genetics, plant genomics, plant biochemistry and breeding. Students and postdocs participate in an annual project meeting with all members from the participating institutions and attend one scientific meeting per year in this area of research. How have the results been disseminated to communities of interest? The most relevant communities have the results of this work disseminated in the form of publications and verbally through seminars and other speaking venues by the PI and the PI and other members of the laboratory when they attend and present posters or talks describing progress and work to date. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? The long term goal of the proposed research is to further our understanding of the biosynthesis and function of essential micronutrients in plants such that a sound scientific basis for the manipulation of their levels in crops, and improvement of global human health, can be undertaken. To enhance our knowledge of the polygenic nature of these compounds in agricultural seeds, and to provide the basis for expanding our research to include other water soluble vitamins and essential amino acids in plant based foods, we have transferred and leverage dinformation involving fundamental biological aspects of biosynthesis of these compounds from the model system Arabidopsis to the economically important crop maize. Using data from Arabidopsis, we have identified orthologs for carotenoid (pro and non-pro vitamin A) and tocopherol (vitamin E) biosynthetic pathways in the maize genome. Whole genome and candidate gene association studies in both maize and Arabidopsis have identified which pathway genes and their functional variant alleles impact the target traits. Nested association mapping has revealed the genetic architecture for the traits in maize and shown that vitamin E has a much larger number of novel loci involved that are clearly not the already characterized pathway genes. We have generated whole transcriptome expression profiles across seed development to help delineate potential candidate genes responsible for traits. Not only will this enable a comparative analysis of the genetic architecture of these traits between Arabidopsis, a dicot, selting species with maize, a monocot, outcrossing species, but it will also be directly useful for improving vitamin content in crops.

Publications

• Type: Journal Articles Status: Submitted Year Published: 2013 Citation: Gonzalez-Jorge S, Ha SH, Magallanes-Lundback M, Ullrich-Gilliland L, Zhou A, Lipka AE, Nguyen YH, Angelovici R, Lin H, Cepela J, Little H, Buell CR, Gore MA and DellaPenna D. (2013) Carotenoid Cleavage Dioxygenase 4 is a Negative Regulator of ?-carotene content in Arabidopsis Seed. Submitted to The Plant Cell.
• Type: Journal Articles Status: Awaiting Publication Year Published: 2013 Citation: Angelovici R, Lipka AE, Deason N, GonzalezJorge S, Lin H, Cepela J, Buell CR, Gore MA and DellaPenna D. (2013) Genome-wide analysis of branched-chain amino acid levels in Arabidopsis seed. The Plant Cell, In Press
• Type: Journal Articles Status: Published Year Published: 2013 Citation: Lipka AE, Gore MA, Magallanes-Lundback M, Mesberg A, Lin H, Tiede T, Chen C, Buell CR, Buckler ES, Rocheford T, DellaPenna D. (2013) Genome-Wide Association Study and Pathway Level Analysis of Tocochromanol Levels in Maize Grain. Genes, Genomes and Genetics. 2013 Jun 3. doi:pii: g3.113.006148v1. 10.1534/g3.113.006148.

Progress 01/01/12 to 12/31/12

Outputs
OUTPUTS: The long term goal of the proposed research is to further our understanding of the biosynthesis and function of essential micronutrients in plants such that a sound scientific basis for the manipulation of their levels in crops, and improvement of global human health, can be undertaken. To enhance our knowledge of the polygenic nature of these compounds in agricultural seeds, and to provide the basis for expanding our research to include other water soluble vitamins and essential amino acids in plant based foods, we plan to transfer and leverage information involving fundamental biological aspects of biosynthesis of these compounds from the model system Arabidopsis to the economically important crops maize. Using data from Arabidopsis, we will identify orthologs for carotenoid (pro and non-pro vitamin A) and tocopherol (vitamin E) biosynthetic pathways in the maize genome. Whole genome and candidate gene association studies in both maize and Arabidopsis will be used to identify novel genes, functional variant alleles, and the genetic architecture of generation whole transcriptome sequencing to delineate potential candidate genes responsible for traits. Not only will this enable a comparative analysis of the genetic architecture of these traits between Arabidopsis, a dicot, selfing species with maize, a monocot, outcrossing species, but it will also be directly useful for improving vitamin content in crops through on-going breeding programs. PARTICIPANTS: Maria Magallanes-Lundback, MSU; Sabrina Jorge, MSU; Ruthie Angelovici, MSU; Alex Mesberg, MSU. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Carotenoids and tocochromanols are also antioxidants and provide a range of additional health benefits related to vision, heart disease and specific cancers. For example, elevated levels of dietary lutein and zeaxanthin are associated with a decreased rate and delayed onset of age-related macular degeneration (AMD), likely because they quench free radicals and attenuate blue light intensity, reducing oxidative stress to the retina. Thus, understanding and manipulating the levels of specific essential nutrients like carotenoids and tocochromanols in plants will allow a direct means for affecting the levels of these compounds in the food supply to positively impact populations, both in developed and developing countries.

Publications

• DellaPenna, D., O'Connor, S.E. 2012. Plant gene clusters and opiates. Science 517:1648-49. Gongora-Castillo, E., Childs, K.L., Fedewa, G., Hamilton, J.P., Liscombe, D.K. Magallanes, M., Mandadi, K.K., Nims, E., Runguphan, W., Vaillancourt, B., Varbanova-Herde, M., DellaPenna, D., McKnight, T.D., OConnor, S. and Buell, C.R. 2012 Development of transcriptomic resources for interrogating the biosynthesis of monoterpene indole alkaloids in medicinal plant species. In Press PlosOne Yeo, Y.S., Nybo, S.E., Chittiboyina, A.G., Weerasooriya, A.D., Wang, Y.H., Gongora-Castillo, E., Vaillancourt, B., Buell, C.R., DellaPenna, D., Celiz, M.D., Jones, A.D., Wurtele, E.S., Ransom, N., Dudareva, N., Shabaan, K.A., Tibrewal, N., Chandra, S., Smillie, T., han, I.A., Coates, R.M., Watt, D.S. and Chappell, J. 2012 Functional identification of valerena-1,10-diene synthase, a terpene synthase catalyzing a unique chemical cascade in the biosynthesis of biologically active sesquiterpenes in Valeriana officinalis. In Press J Biol Chem. Gongora-Castillo, E., Fedewa, G., Yeo, Y., Chappell, J., DellaPenna, D. and Buell, C.R. 2012 Genomic approaches for interrogating the biochemistry of medicinal plant species. In Methods in Enzymology: Natural product biosynthesis by microorganisms and plants. 517:139-59. Edited by David A. Hopwood. Fitzpatrick, T.B., Basset, G.J.C., Borel, P., Carrari, F., DellaPenna, D., Fraser, P.D., Hellmann, H., Osorio, S., Rothan, C., Valpuesta, V., Caris-Veyrat, C. and Fernie, A.R. 2012 Vitamin deficiencies in humans: Can Plant Science help The Plant Cell 24:395-414.

Progress 01/01/11 to 12/31/11

Outputs
OUTPUTS: The longterm goal of the proposed research is to further our understanding of the biosynthesis and function of essential micronutrients in plants such that a sound scientific basis for the manipulation of their levels in crops, and improvement of global human health, can be undertaken. To enhance our knowledge of the polygenic nature of these compounds in agricultural seeds, and to provide the basis for expanding our research to include other water soluble vitamins and essential amino acids in plant based foods, we plan to transfer and leverage information involving fundamental biological aspects of biosynthesis of these compounds from the model system Arabidopsis to the economically important crop maize. Using data from Arabidopsis, we will identify orthologs for carotenoid (pro and non-pro vitamin A) and tocopherol (vitamin E) biosynthetic pathways in the maize genome. Whole genome and candidate gene association studies in both maize and Arabidopsis will be used to identify novel genes, functional variant alleles, and the genetic architecture of micronutrient traits. Genetic mapping data will be integrated with developing seed expression data obtained using next generation whole transcriptome sequencing to delineate potential candidate genes responsible for traits. Not only will this enable a comparative analysis of the genetic architecture of these traits between Arabidopsis, a dicot, selfing species with maize, a monocot, outcrossing species, but it will also be directly useful for improving vitamin content in crops through on-going breeding programs. PARTICIPANTS: Maria Magallanes-Lundback, MSU; MSU; Sabrina Jorge, MSU; Emily McKinney, MSU; EunHa Kim, MSU, Jacobo Argano, MSU. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Carotenoids and tocochromanols are also antioxidants and provide a range of additional health benefits related to vision, heart disease and specific cancers. For example, elevated levels of dietary lutein and zeaxanthin are associated with a decreased rate and delayed onset of age-related macular degeneration (AMD), likely because they quench free radicals and attenuate blue light intensity, reducing oxidative stress to the retina. Thus, understanding and manipulating the levels of specific essential nutrients like carotenoids and tocochromanols in plants will allow a direct means for affecting the levels of these compounds in the food supply to positively impact populations, both in developed and developing countries.

Publications

• DellaPenna, D and Mene-Saffrane L (2011) Vitamin E (one of 11 chapters). Advances in Botanical Research: Biosynthesis of Vitamins in Plants. Fabrice Rebeille and Roland Douce, Editors. In press.
• The Potato Genome Sequencing Consortium (2011) (89 investigators; MSU coauthors: Brett R. Whitty, Brieanne Vaillancourt, Haining Lin, Alicia N. Massa, Michael Geoffroy, Steven Lundback, Dean DellaPenna, C. Robin Buell) Genome sequence and analysis of the tuber crop potato. Nature 475:189-195.

Progress 01/01/10 to 12/31/10

Outputs
OUTPUTS: The long-term goal of the proposed research is to further our understanding of the biosynthesis and function of essential micronutrients in plants such that a sound scientific basis for the manipulation of theirlevels in crops, and the consequences of this manipulation, can be undertaken. This goal requires a detailed knowledge of the biochemical and molecular regulation of the pathway sand the biochemical and physiological functions of the target compounds, tocopherols (vitamin E) and carotenoids. We have been continuing our genetic and biochemical dissection of the pathway in plants and cyanobacteria and have now isolated all biosynthetic genes required for tocopherol synthesis and identified several QTL defining novel loci affecting the pathway that are at various stages of map based cloning. Several of these genes have been studied in detail and the consequences of altering their expression for pathway flux and tocopherol composition analyzed. Recently we have initiated projects in association mapping for these traits in Arabidopsis and maize. PARTICIPANTS: Maria Magallanes-Lundback, MSU; Song, W, MSU; Sabrina Jorge, MSU; Emily McKinney, MSU; EunHa Kim, MSU TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
In addition to identifying new loci involved in vitamin E and carotenoid synthesis and accumulation in plants, an off shoot of the research is that disruption of tocopehrol synthesis leads under certain conditions to inhibition of carbohydrate transport from source tissues resulting in massive accumulation of starch and sugars in leaves. We are studying this process and its application to crops as it holds significant promise for manipulating crops for ethanol production. Our extension of the work into association mapping will allow us to identify alleles and loci that can be readily transferred into breeding programs.

Publications

• Song W, Maeda H, DellaPenna D (2010) Mutations of the ER to plastid lipid transporters (TGD1, 2, 3 and 4) and the ER oleate desaturase (FAD2) suppress the low temperature-induced phenotype of the tocopherol deficient Arabidopsis vte2 mutant. The Plant Journal 62:1004-18. Mene-Saffrane L and DellaPenna D (2010) Biosynthesis, Regulation and Functions of Tocochromanols in Plants. Plant Physiology and Biochemistry 8:301-9.
• Mene-Saffrane L, Jones AD, DellaPenna D. (2010) Plastochromanol-8 and tocopherols are essential lipid-soluble antioxidants during seed desiccation and quiescence in Arabidopsis Proc Natl Acad Sci U S A. 107:17815-20.
• Yan J, Bermudez Kandianis C, Harjes CE, Bai L, Kim EH, Yang X, Skinner DJ, Fu Z, Mitchell S, Li Q, Salas Fernandez MG, Zaharieva M, Babu R, Fu Y, Palacios N, Li J, DellaPenna D, Brutnell T, Buckler ES, Warburton EL, Rocheford T. (2010) Rare Genetic Variation at Zea mays crtRB1 Increases b-carotene in Maize Grain Nature Genetics 42:322-7.

Progress 01/01/09 to 12/31/09

Outputs
OUTPUTS: The longterm goal of the proposed research is to further our understanding of the biosynthesis and function of tocopherols in plants such that a sound scientific basis for the manipulation of vitamin E levels in crops, and the consequences of this manipulation, can be undertaken. This goal requires a detailed knowledge of the biochemical and molecular regulation of the pathway and the biochemical and physiological functions of tocopherols in plastids. We have been continuing our genetic and biochemical dissection of the pathway in plants and cyanobacteria and have now isolated all biosynthetic genes required for tocopherol synthesis and identified several QTL defining novel loci affecting the pathway that are at various stages of map based cloning. Several of these genes have been studied in detail and the consequences of altering their expression for pathway flux and tocopherol composition analyzed. Recently we have initiated projects in association mapping for these traits in Arabidopsis and maize. PARTICIPANTS: Maria Magallanes-Lundback, MSU; Song, W, MSU; Kim, J, MSU; Ohlrogge, J, MSU; Shachar-Hil,l Y, MSU, Smith J, MSU; Bia L, Cornell; Brutnell, T Cornell; Li T, UC Davis, Zhang R, Madison; Kramer, D WSU; Cruz, J WSU, Sharkey, T MSU. TARGET AUDIENCES: No information provided PROJECT MODIFICATIONS: We have included association mapping in the repertoire of our approaches to studying the Vitamin E and other pathways in plants.

Impacts
In addition to identifying new loci involved in vitamin E synthesis and accumulation in plants, an off shoot of the research is that disruption of tocopehrol synthesis leads under certain conditions to inhibition of carbohydrate transport from source tissues resulting in massive accumulation of starch and sugars in leaves. We are studying this process and its application to crops as it holds significant promise for manipulating crops for ethanol production. Our extension of the work into association mapping will allow us to identify alleles and loci that can be readily transferred into breeding programs.

Publications

• John Ohlrogge, Doug Allen, Bill Berguson, Dean DellaPenna, Yair Shachar-Hill, Sten Stymne (2009) Driving on Biomass. SCIENCE Volume: 324 Issue: 5930 Pages: 1019-1020
• Joonyul Kim, James J. Smith, Li Tian and Dean DellaPenna (2009) The Evolution and Function of Carotenoid Hydroxylases in Arabidopsis. PLANT AND CELL PHYSIOLOGY Volume: 50 Issue: 3 Pages: 463-479
• RU ZHANG, JEFFREY A. CRUZ, DAVID M. KRAMER, MARIA E. MAGALLANES-LUNDBACK, DEAN DELLAPENNA and THOMAS D. SHARKEY (2009) Moderate heat stress reduces the pH component of the transthylakoid proton motive force in light-adapted, intact tobacco leaves. PLANT CELL AND ENVIRONMENT Volume: 32 Issue: 11 Pages: 1538-1547
• Ling Bai, Eun-Ha Kim, Dean DellaPenna and Thomas P. Brutnell (2009) Novel lycopene epsilon cyclase activities in maize revealed through perturbation of carotenoid biosynthesis. PLANT JOURNAL Volume: 59 Issue: 4 Pages: 588-599

Progress 01/01/08 to 12/31/08

Outputs
OUTPUTS: The longterm goal of the proposed research is to further our understanding of the biosynthesis and function of tocopherols in plants such that a sound scientific basis for the manipulation of vitamin E levels in crops, and the consequences of this manipulation, can be undertaken. This goal requires a detailed knowledge of the biochemical and molecular regulation of the pathway and the biochemical and physiological functions of tocopherols in plastids. We have been continuing our genetic and biochemical dissection of the pathway in plants and cyanobacteria and have now isolated all biosynthetic genes required for tocopherol synthesis and identified several QTL defining novel loci affecting the pathway that are at various stages of map based cloning. Several of these genes have been studied in detail and the consequences of altering their expression for pathway flux and tocopherol composition analyzed. PARTICIPANTS: M. Magallanes-Lundback, MSU; W Song, MSU; H Maeda, MSU; T Sage, Univ. of Toronto; D Braun, Penn State; RF Baker, Penn State; Y Ma, Penn State; R Last, MSU; N Kobayashi, MSU; R Welti, Kansas State; G Isaac, Kansas State. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
In addition to identifying new loci involved in vitamin E synthesis and accumulation in plants, an off shoot of the research is that disruption of tocopherol synthesis leads under certain conditions to inhibition of carbohydrate transport from source tissues resulting in massive accumulation of starch and sugars in leaves. We are studying this process and its application to crops as it holds significant promise for manipulating crops for ethanol production.

Publications

• Kobayashi, N and DellaPenna D (2008) Tocopherol metabolism, oxidation and recycling under high light stress in Arabidopsis. The Plant Journal. Plant J. 2008 Aug;55(4):607-18
• DellaPenna, D and Last R (2008) Genome-Enabled Approaches Shed New Light on Plant Metabolism Science 320:479-481.
• Maeda H, Sage TL, Giorgis Isaac, Ruth Welti and DellaPenna D (2008) Tocopherols Modulate Extra-Plastidic Polyunsaturated Fatty Acid Metabolism in Arabidopsis at Low Temperature. The Plant Cell 20(2):452-70. Also featured in In this Issue.
• Ma Y, Baker RF, Magallanes-Lundback M, DellaPenna D, Braun DM. (2008) Tie-dyed1 and Sucrose export defective1 act independently to promote carbohydrate export from maize leaves. Planta 227(3):527-38.

Progress 01/01/07 to 12/31/07

Outputs
OUTPUTS: The longterm goal of the proposed research is to further our understanding of the biosynthesis and function of tocopherols in plants such that a sound scientific basis for the manipulation of vitamin E levels in crops, and the consequences of this manipulation, can be undertaken. This goal requires a detailed knowledge of the biochemical and molecular regulation of the pathway and the biochemical and physiological functions of tocopherols in plastids. We have been continuing our genetic and biochemical dissection of the pathway in plants and cyanobacteria and have now isolated all biosynthetic genes required for tocopherol synthesis and identified several QTL defining novel loci affecting the pathway that are at various stages of map based cloning. Several of these genes have been studied in detail and the consequences of altering their expression for pathway flux and tocopherol composition analyzed. PARTICIPANTS: Maria Magallanes-Lundback, MSU Song, W, MSU Maeda, H, MSU Sage, TL, Univ of Toronto, Canada Braun DM, Penn State Ma Y, Penn State Baker RF, Penn State Welsch R, U Freiburg, Germany Maass D, U Freiburg, Germany Voegel T, U Freiburg, Germany Beyer, P, , U Freiburg, Germany Li, T, Noble foundation, Oklahoma Dixon, R, Noble foundation, Oklahoma

Impacts
In addition to identifying new loci involved in vitamin E synthesis and accumulation in plants, an off shoot of the research is that disruption of tocopehrol synthesis leads under certain conditions to inhibition of carbohydrate transport from source tissues resulting in massive accumulation of starch and sugars in leaves. We are studying this process and its application to crops as it holds significant promise for manipulating crops for ethanol production.

Publications

• Ma Y, Baker RF, Magallanes-Lundback M, Dellapenna D, Braun DM. (2007) Tie-dyed1 and Sucrose export defective1 act independently to promote carbohydrate export from maize leaves. 2007 Oct 9 [Epub ahead of print]
• Maeda, H., Song, W., Sage T.L. and DellaPenna, D. (2007) Tocopherols Play a Limited Role in Photoprotection but a Crucial Role in Chilling Adaptation in Arabidopsis Leaves. The Proceeding of the 17th International Symposium on Plant Lipids, ISBN: 978-1-4276-1965-5
• Welsch R, Maass D, Voegel T, Dellapenna D, Beyer P. (2007) Transcription Factor RAP2.2 and Its Interacting Partner SINAT2: Stable Elements in the Carotenogenesis of Arabidopsis Leaves. Plant Physiol. 145:1073-85.
• Tian L, DellaPenna D, Dixon RA. (2007) The pds2 mutation is a lesion in the Arabidopsis homogentisate solanesyltransferase gene involved in plastoquinone biosynthesis. Planta. 2007 Jun 14; [Epub ahead of print]
• Maeda H, DellaPenna D. (2007) Tocopherol functions in photosynthetic organisms. Curr Opin Plant Biol. 10(3):260-5.
• DellaPenna, D. (2007) Biofortification of plant-based food: enhancing folate levels by metabolic engineering. Proc Natl Acad Sci U S A. 104(10):3675-6

Progress 01/01/06 to 12/31/06

Outputs
The longterm goal of the proposed research is to further our understanding of the biosynthesis and function of tocopherols in plants and other photosynthetic organisms such that a sound scientific basis for the manipulation of vitamin E levels in crops, and the consequences of this manipulation, can be undertaken. This goal requires a detailed knowledge of the biochemical and molecular regulation of the pathway and the biochemical and physiological functions of tocopherols in plants. We have been continuing our molecular and genetic dissection of the pathway in plants and have now isolated all biosynthetic genes required for tocopherol synthesis. Several of these genes have been studied in detail and the consequences of altering their expression for pathway flux and tocopherol composition analyzed. The consequences of altering tocopherols for photosynthetic processes and stress are now being pursued. We have also pursued quantitative trait analysis for tocopherols and identified several new loci that impact tocopherol levels in seed. These loci are being physically isolated. An NIH/Gates foundation grant to support this work was funded in 2005.

Impacts
Understanding how to manipulate the Vitamin E level of food crops will lead to broad health benefits for the entire population.

Publications

• Sakuragi, Y., Maeda, H., DellaPenna, D. and Bryant, D.A. 2006. Alpha-Tocopherol plays a role in photosynthesis and macronutrient homeostasis of the cyanobacterium Synechocystis sp. PCC 6803 that is independent of its antioxidant function. Plant Physiology 141: 508-521.
• DellaPenna, D. and Pogson, B.J. 2006. Vitamin Synthesis In Plants: Tocopherols and Carotenoids. Ann. Rev. Plant. Biol. 57:711-738.
• Foyer, C.H., DellaPenna, D. and Van Der Straeten, D. 2006. A new era in plant metabolism research reveals a bright future for bio-fortification and human nutrition. Physiologia Plantarum 126: 289-290.
• Ruebelt, M.C., Lipp, M., Reynolds, T.L., Schmuke, J.J., Astwood, J.D., DellaPenna, D., Engel, K.H. and Jany, K.D. 2006. Application of two-dimensional gel electrophoresis to interrogate alterations in the proteome of genetically modified crops. 3. Assessing unintended effects. J Agric Food Chem. 54:2169-77
• DellaPenna, D. and Last, R.L. 2006. Progress in the dissection and manipulation of plant vitamin E biosynthesis. Physiologia Plantarum 126:356-368.
• Gilliland, L.U., Magallanes-Lundback, M., Hemming, C., Supplee, A., Koornneef, M., Bentsink, L. and DellaPenna, D. 2006. The genetic basis for natural variation in seed vitamin E levels in Arabidopsis thaliana. Proceedings of the National Academy of Sciences 103:18834-41.
• Maeda, M., Song, W., Sage, T. and DellaPenna, D. 2006. Arabidopsis vitamin E-deficient Mutants Exhibit a Cold Sensitive Phenotype Independent of Photooxidative Damage and Caused by Misregulation of Photoassimilate Export from Source Leaves. The Plant Cell 18:2710-32.

Progress 01/01/05 to 12/31/05

Outputs
The longterm goal of the proposed research is to further our understanding of the biosynthesis and function of tocopherols in plants and other photosynthetic organisms such that a sound scientific basis for the manipulation of vitamin E levels in crops, and the consequences of this manipulation, can be undertaken. This goal requires a detailed knowledge of the biochemical and molecular regulation of the pathway and the biochemical and physiological functions of tocopherols in plastids. We have been continuing our molecular and genetic dissection of the pathway in plants and have now isolated all biosynthetic genes required for tocopherol synthesis. Several of these genes have been studied in detail and the consequences of altering their expression for pathway flux and tocopherol composition analyzed. The consequences of altering tocopherols for photosynthetic processes and stress are now being pursued. We now have the tools to begin altering multiple pathway steps in a single plant to test for additive or synergistic impact on the pathway. We are also expanding our studies to include the interaction of tocopherols with other antioxidants in the plant and whether the absence or several fold overabundance can compensate for the loss on individual antioxidant components. An NSF grant in support of this research was funded in 2003 and an NIH/Gates foundation grant in 2005.

Impacts
Understanding how to manipulate the Vitamin E level of food crops will lead to broad health benefits for the entire population.

Publications

• Maeda M, Sakuragi Y, Bryant DA and DellaPenna D (2005) Tocopherols protect Synechocystis sp. strain PCC 6803 from lipid peroxidation. Plant Physiol 138:1422-35.
• DellaPenna, D (2005) A decade of progress in understanding vitamin E synthesis in plants. J Plant Physiol. 162:729-37
• DellaPenna, D (2005) Progress in the dissection and manipulation of vitamin E synthesis. Trends in Plant Sciences. In Press

Progress 01/01/04 to 12/31/04

Outputs
The longterm goal of the proposed research is to further our understanding of the biosynthesis and function of tocopherols in plants and other photosynthetic organisms such that a sound scientific basis for the manipulation of vitamin E levels in crops, and the consequences of this manipulation, can be undertaken. This goal requires a detailed knowledge of the biochemical and molecular regulation of the pathway and the biochemical and physiological functions of tocopherols in plastids. We have been continuing our molecular and genetic dissection of the pathway in plants and have now isolated all biosynthetic genes required for tocopherol synthesis. Several of these genes have been studied in detail and the consequences of altering their expression for pathway flux and tocopherol composition analyzed. The consequences of altering tocopherols for photosynthetic processes and stress are now being pursued. We now have the tools to begin altering multiple pathway steps in a single plant to test for additive or synergistic impact on the pathway. We are also expanding our studies to include the interaction of tocopherols with other antioxidants in the plant and whether the absence or several fold overabundance can compensate for the loss on individual antioxidant components. An NSF grant in support of this research was funded in 2003. This proposal utilizes a variety of mutant and transgenic Arabidopsis lines modified in their ability to accumulate different levels and types of specific tocopherols in both leaves and seeds. The effects of these modifications on physiology, membrane biochemistry, stress tolerance and other components of the plastid antioxidant network are being studied in both seeds and leaves in regard to the impact.

Impacts
Understanding how to manipulate the Vitamin E level of food crops will lead to broad health benefits for the entire population, most notably with regard to atherosclerosis and certain forms of cancer.

Publications

• Scott E. Sattler, Laura U. Gilliland, Maria Magallanes-Lundback, Mike Pollard and Dean DellaPenna. (2004) Vitamin E is essential for seed longevity and preventing lipid peroxidation during germination. Plant Cell 16:1419-32.
• Scott E. Sattler, Zigang Cheng and Dean DellaPenna (2004) From Arabidopsis to Agriculture: Engineering improved Vitamin E content in soybean. Trends in Plant Sciences 9:365-7.

Progress 01/01/03 to 12/31/03

Outputs
The longterm goal of the proposed research is to further our understanding of the biosynthesis and function of tocopherols in plants and other photosynthetic organisms such that a sound scientific basis for the manipulation of vitamin E levels in crops, and the consequences of this manipulation, can be undertaken. This goal requires a detailed knowledge of the biochemical and molecular regulation of the pathway and the biochemical and physiological functions of tocopherols in plastids. We have been continuing our genetic dissection of the pathway in plants and have now isolated all biosynthetic genes required for tocopherol synthesis. Several of these genes have been studied in detail and the consequences of altering their expression for pathway flux and tocopherol composition analyzed. We now have the tools to begin altering multiple pathway steps in a single plant to test for additive or synergistic impact on the pathway. We are also expanding our studies to include the interaction of tocopherols with other antioxidants in the plant and whether the absence or several fold overabundance can compensate for the loss on individual antioxidant components.

Impacts
Understanding how to manipulate the Vitamin E level of food crops will lead to broad health benefits for the entire population, most notably with regard to atherosclerosis and certain forms of cancer.

Publications

• Collakova, E. and D. DellaPenna. (2003) The Role of Homogentisate Phytyltransferase and Other Tocopherol Pathway Enzymes in the Regulation of Tocopherol Synthesis during Abiotic Stress. Plant Physiology 133: 930-940.
• Sattler, S. E., E.B. Cahoon, S.J. Coughlan and D. DellaPenna (2003) Characterization of tocopherol cyclases from higher plants and cyanobacteria: Evolutionary implications for tocopherol synthesis and function. Plant Physiology 132: 2184-2195.
• Cheng, Z., Sattler S., Maeda, H., Sakuragi, Y., Bryant, D. and D. DellaPenna (2003) Highly Divergent Methyltransferases Catalyze a Conserved Reaction in Tocopherol and Plastoquinone Synthesis in Cyanobacteria and Photosynthetic Eukaryotes. Plant Cell 15: 2343-2356.
• Collakova, E. and D. DellaPenna. (2003) Homogentisate Phytyltransferase Activity Is Limiting for Tocopherol Biosynthesis in Arabidopsis. Plant Physiology 131: 632-642.

Progress 01/01/02 to 12/31/02

Outputs
The longterm goal of the proposed research is to further our understanding of the biosynthesis and function of tocopherols in plants and other photosynthetic organisms such that a sound scientific basis for the manipulation of vitamin E levels in crops, and the consequences of this manipulation, can be undertaken. This goal requires a detailed knowledge of the biochemical and molecular regulation of the pathway and the biochemical and physiological functions of tocopherols in plastids. We have been continuing our genetic dissection of the pathway in plants and have now isolated all biosynthetic genes required for tocopherol synthesis. Several of these genes have been studied in detail and the consequences of altering their expression for pathway flux and tocopherol composition analyzed. We now hat to tools to begin altering multiple pathway steps in a single plant to test for additive or synergistic impact on the pathway. We are also expanding our studies to include the interaction of tocopherols with other antioxidants in the plant and whether the absence or several fold overabundance can compensate for the loss on individual antioxidant components.

Impacts
Understanding how to manipulate the Vitamin E level of food crops will lead to broad health benefits for the entire population, most notably with regard to atherosclerosis and certain forms of cancer.

Publications

• Tseyage, Y., D. Shintani and D. DellaPenna (2002) Overexpression of hydroxyphenylpyruvate dioxygenase in Arabidopsis and the consequence for tocopherol synthesis. Plant Physiology and Biochemistry 40:913-920.
• Collakova, E. and D. DellaPenna (2003) Homogentisate Phytyltransferase Activity Is Limiting for Tocopherol Biosynthesis in Arabidopsis. Plant Physiology. In Press.
• Scott E. Sattler, Edgar B. Cahoon, Sean J. Coughlan, Robert Meeley and Dean DellaPenna (2003) Cloning and characterization of tocopherol cyclases from higher plants and cyanobacteria, Evolutionary implications for tocopherol synthesis and function. Submitted to Plant Physiology.
• Shintani, D. K., Z. Cheng and D. DellaPenna (2002) The role of 2-methyl-6-phytylbenzoquinone methyltransferase in determining tocopherol composition in Synechocystis sp. PCC6803. FEBS Letters 511:1-5.

Progress 01/01/01 to 12/31/01

Outputs
The long term goal of the proposed research is to further our understanding of the biosynthesis of tocopherols in higher plants (alpha, beta, gamma, delta-tocopherols and tocotrienols) such that a sound scientific basis for molecular manipulation of tocopherol quantity and composition in a wide variety agricultural crops and tissues can be implemented in the near future. This goal requires detailed knowledge of the biochemical and molecular regulation of the pathway, in particular, the Tocopherol Prenyl Transferase (TPTase) enzyme, which likely regulates pathway flux. We have already identified TPTase from Synechocystis PCC6803 by gene disruption, used it to isolate an Arabidopsis ortholog (AtTPTase) and have assayed both proteins expressed in E. coli. A truncated EST encoding a monocot (wheat) TPTase ortholog has also been identified and a full-length clone will be similarly isolated and expressed in E coli. The three E. coli expressed TPTases will be biochemically characterized in detail and these data related to the tocopherol end products produced by each organism. In a complementary set of experiments, overexpression and antisense inhibition of AtTPTase expression using both constitutive and seed specific promoters will be performed to test the hypothesis that TPTase activity levels are important for regulating tocopherol pathway flux in various Arabidopsis tissues.

Impacts
Understanding how to manipulate the Vitamin E level of food crops will lead to broad health benefits for the entire population, most notably with regard to atherosclerosis and certain forms of cancer.

Publications

• Collakova, E. and DellaPenna, D. 2001. Isolation and functional analysis of homogentisate phytyltransferase from Synechocystis sp. PCC6803 and Arabidopsis thaliana. Plant Physiol. 127:1113-1124.
• Shintani, D. Cheng, Z. and DellaPenna, D. 2002. The role of 2-methyl-6-phytylbenzoquinone methyltransferase in determining tocopherol composition in Synechocystis sp. PCC6803 . FEBS Lett. In press.
• Tseyage, Y., Shintani D. and DellaPenna D. 2002. Overexpression of hydroxyphenylpyruvate dioxygenase in Arabidopsis and the consequence for tocopherol synthesis. Plant Physiol. Biochem. submitted.