Tony  Chen
Tony Chen
Professor Emeritus

My research focuses on biotechnology and stress and postharvest physiology.

OSU Campus
Department of Horticulture
4017 Ag and Life Sciences Bldg
Corvallis, OR 97331-7304
United States
(541) 737-5444

Research

The research in my lab focuses on three areas: 1) cloning and characterization of regulatory genes contributing to barley cold tolerance; 2) improving cold tolerance by metabolic engineering of glycinebetaine synthesis and by over-expression of CBF genes; and 3). improvement of potato cold tolerance by over-expressing cDNAs of Arabidopsis CBF genes.

Characterization of Regulatory Genes Contributing to Barley Cold Tolerance A major cold tolerance QTL cluster has been identified on barley chromosome 7 (5H). Recent studies in Arabidopsis and other dicots have demonstrated that CBF/DREB genes act as key regulators of plant cold tolerance and other stress responses. We have cloned 15 barley CBF gene family members to date and mapped 13 of the barley CBF genes directly adjacent to the major cold tolerance QTL region. Assignment of map positions for the remaining barley CBF genes, as well as saturation of this area with additional markers, is in progress. The size of the barley CBF gene family and response of each member to environmental stress (cold, drought, etc.) is being characterized. A barley BAC clone has been mapped to a position directly under the cold tolerance QTL peak, and overlapping BAC clones identified as a first step towards a chromosome walk across this region. A set of 59 DM near-isogenic lines is being densely genotyped to define the segments of chromosome 7(5H) that play a central role in conveying the low temperature tolerance phenotype. Determination of the genes/regions conferring superior cold tolerance will allow development of winter hardy barley varieties that retain the superior malting traits of current spring varieties.

Genetic engineering of glycinebetaine synthesis in tomato protects seeds, plants and flowers from chilling damage Tomato plants normally do not accumulate glycinebetaine (GB) and are susceptible to chilling stress. Exposure to temperatures below 10°C causes various symptoms of chilling injury and greatly decreases fruit set (the number of fruits per plant) in most tomato cultivars. Conventional breeding efforts have failed to produce tomato cultivars with satisfactory cold tolerance and, with this in mind, we transformed tomato (Lycopersicon esculentum Mill. cv. 'Moneymaker') with the codA gene of Arthrobacter globiformis, which encodes choline oxidase. This enzyme catalyzes the conversion of choline to GB. Transgenic tomato plants expressed the codA gene and synthesized choline oxidase, accumulating up to 0.23 mol GB/g fresh weight in their leaves. GB-accumulating transgenic tomato plants were more tolerant to chilling stress than wild-type plants at various stages of growth and development from the germination of seeds to the production of fruit. At the reproductive stage, the GB-accumulating transgenic tomato plants yield on average 30% more fruits than wild-type plants after an episode of chilling stress. Our results demonstrate that introduction, by metabolic engineering, of the biosynthetic pathway to GB in tomato is an effective strategy for improving fruit production under cold-stress conditions.

Improvement of potato cold tolerance by over-expressing cDNAs of Arabidopsis CBF genes We transformed potato (S. tuberosum, ST) and a related species, S. commersonii (SC), with the Arabidopsis CBF1, 2 and 3 genes driven by either the CaMV35S promoter (a constitutive promoter) or the Rd29A/COR78 promoter (a cold-inducible promoter) and characterizing the stress tolerance of the transgenic plants. Freezing tolerance had been evaluated for 10 transgenic lines of S. commersonii and 3 transgenic lines of S. tuberosum transformed with 35S::CBF1. Under non-acclimated conditions, there was a maximal increase of 4°C in freezing tolerance in transgenic SC lines, and of 2°C for ST lines. After two weeks of cold acclimation at 2°C, transgenic SC lines showed a further increase of 3°C in freezing tolerance, whereas there was no further increase in freezing tolerance in ST lines. We have also evaluated the freezing tolerance of transgenic ST lines transformed with Arabidopsis CBF1, CBF2, and CBF3 driven by the Rd29 promoter. ST lines transformed with an Rd29::CBF3 construct had a 4°C increase in freezing tolerance.

 

Teaching

Hort 513 Plant Genetic Engineering, 3 credits.

Biography

Professional Experience

Research Assistant University of Minnesota 1977-1981
Post-doctoral Fellow University of Saskatchewan 1981-1982
Research Associate Plant Biotechnology Institute, Nat. Res. Council of Canada 1982-1983
Assistant Research Officer Alberta Research Council 1983-1986
Assistant Professor Oregon State University 1986-1990
Associate Professor Oregon State University 1990-1993
Professor Oregon State University 1993-present

Educational Background

B.S. 1975 Agronomy, National Taiwan University
M.S. 1979 Plant Physiology, University of Minnesota
Ph.D. 1981 Plant Physiology, University of Minnesota

Publications

Marcela Carvallo,María-Teresa Pino, Zoran Jeknić, Cheng Zou, Colleen Doherty, Shin-Han Shiu, Tony H. H. Chen, and Michael F. Thomashow. 2011 A comparison of the low temperature transcriptomes and CBF regulons of three plant species that differ in freezing tolerance-Solanum commersonii, Solanum tuberosum and Arabidopsis thaliana. J. Exp. Bot. 62:3807-3819.

Shufen Li, Feng Li, Jianwei Wang, Wen Zhang, Qingwei Meng, Tony HH Chen, Norio Murata, Xinghong Yang 2011 Glycinebetaine enhances the tolerance of tomato plants to high temperature during germination of seeds and growth of seedlings. Plant Cell & Environment (Published online July 8, 2011).

Chen, T.H.H. and N. Murata. 2011. Glycinebetaine protects plants against abiotic stress: Mechanisms and biotechnological application. Plant Cell & Environment. 34: 1-20.

 Lars Resman, Glenn Howe, David Jonsen, Madeleine Englund, Nathalie Druart; Jarmo Schrader, Henrik Antii, Thomas Moritz, Jeffrey S. Skinner, Tony Chen and Rishikesh P. Bhalerao 2010 Components acting downstream of SD perception regulate differential cessation of cambial activity in early and late clones of hybrid poplar. Plant Physiology 154: 1294-1303.

Pino, MT, JS. Skinner, EJ Park, Z. Jeknić, PM. Hayes, AH Soeldner,MF.Thomashow, and THH. Chen 2008 Ectopic AtCBF1 overexpression enhances freezing tolerance and induces cold acclimation-associated physiological modifications in potato. Plant Cell and Environment 29: 1259-1272.

Chen, T.H.H. and N. Murata. 2008. Glycinebetaine: an effective protectant against abiotic stress in plants. Trends in Plant Science 13: 499-505.

Szűcs, P., J.S. Skinner, I. Karsai, A. Cuesta-Marcos, K.G. Haggard, A.E. Corey, T.H.H. Chen and P.M. Hayes. 2007. Validation of the VRN-H2/VRN-H1 epistatic model in barley reveals that intron length variation in VRN-H1 may account for a continuum of vernalization sensitivity. Molecular Genetics and Genomics 277:249-261.

Pino, M.T., J.S. Skinner, E.J. Park, Z. Jeknić, P.M. Hayes, M.F. Thomashow, and T.H.H. Chen. 2007. Use of a stress inducible promoter to drive Ectopic AtCBF expression improves Potato freezing tolerance while minimizing negative effects on tuber yield. Plant Biotechnology J. 5: 591-604.

Skinner, J.S., P. Szűcs, J. von Zitzewitz, L. Marquez-Cedillo, T. Filichkin, M.F. Thomashow, E. J. Stockinger, T. H.H. Chen, and P. M. Hayes. 2006. Mapping of barley homologs to genes that regulate low temperature tolerance in Arabidopsis. Theoretical and Applied Genetics 112:832-842.

Park, E.J., Z. Jeknic and T.H.H. Chen. 2006. Exogenous application of glycinebetaine increases chilling tolerance in tomato plants. Plant Cell Physiology 47(6): 706-714.

Benedict, C, JS Skinner, R Meng, Y Chang, R Bhalerao, NPA Huner, CE Finn, THH Chen, and V Hurry. 2006. The CBF1-dependent low temperature signalling pathway, regulon and increase in freeze tolerance are conserved in Populus spp. Plant, Cell and Environment 29: 1259-1272.

Szűcs, P, I Karsai, J von Zitzewitz, LDD Cooper, YQ Gu, THH Chen, PM Hayes, O Anderson, and JS Skinner. 2006. Positional relationships between photoperiod response QTL and photoreceptor and vernalization genes in barley. Theoretical and Applied Genetics 112: 1277–1285.

Chen, T.H.H, M. Uemura, and S. Fujikawa. 2006. Cold Hardiness in Plants: Molecular genetics, cell biology, and physiology. CABI Publishing, Oxfordshire,UK.

Skinner, J.S., J. von Zitzewitz, L. Marquez-Cedillo, T. Filichkin, P. Szucs, K. Amundsen, E. Stockinger, M.F. Thomashow, T.H.H. Chen, and P.M. Hayes. 2006. Barley contains a large CBF gene family associated with quantitative cold tolerance traits. In: T.H.H. Chen, M. Uemura, and S. Fujikawa (Eds.), Cold Hardiness in Plants: Molecular genetics, cell biology, and physiology. CABI Publishing, Oxfordshire,UK. Page 30 - 52.

Pino, M.T., J. S. Skinner, Z. Jekni?, E.J. Park, P.M. Hayes, and T.H.H. Chen. 2006 Ectopic Over-expression of AtCBF1 in Potato Enhances Freezing Tolerance. In: T.H.H. Chen, M. Uemura, and S. Fujikawa (Eds.), Cold Hardiness in Plants: Molecular genetics, cell biology, and physiology. CABI Publishing, Oxfordshire, UK.Page 103- 123.

Cooper, L.L.D., J. von Zitzewitz, J. S. Skinner, P. Sz?cs, I. Karsai, Enrico Francia, A. M. Stanca, N. Pecchioni, D. A Laurie, T.H.H. Chen, and P. M. Hayes. 2006. The genetic basis of vernalization response in barley. In: T.H.H. Chen, M. Uemura, and S. Fujikawa (Eds.), Cold Hardiness in Plants: Molecular genetics, cell biology, and physiology. CABI Publishing, Oxfordshire, UK Page 64 - 75.

Benedict,C., J.S. Skinner, R. Meng, Y. Chang, R Bhalerao, C. Finn, T.H.H. Chen, V. Hurry. 2006. The Role of the CBF-Dependent Signalling Pathway in Woody Perennials. In: T.H.H. Chen, M. Uemura, and S. Fujikawa (Eds.), Cold Hardiness in Plants: Molecular genetics, cell biology, and physiology. CABI Publishing, Oxfordshire, UK. Page 167 - 180.

Park E.J. and T.H.H.Chen. 2006. Improvement of cold tolerance in horticultural crops by genetic engineering. Journal of Crop Improvement 17: 69-120.