Ph.D. Environmental and Forestry Biology
2000, State University of New York
Research Focus Areas
Biotechnology and Genomics
Economically Important Woody Plants
The main research focus of my laboratory is genomics and biotechnology with woody plant species with economically important values. Primary ongoing projects include:
1. Molecular dissection of the mechanisms underpinning the vegetative/reproductive transition in Metasequoia glyptostroboides (dawn redwood).
Funded by US Department of Agriculture CSREES, this project is aimed to identify genes that play key roles during vegetative/reproductive transition. The award will support four student internships and two principle investigators from Clemson University on a two-week trip to China in the summers of 2010-2012. Interested students can sign up for Gen 490 (Special Topics in Genetics)/GEN 806 (Special Problems in Genetics) (one credit) in Summer I.
2. Genetic engineering for Septoria disease resistance in hybrid poplar
Septoria musiva, one of the most damaging pathogens in Populus spp., causes leaf spot and canker diseases and is directly responsible for plantation failure. Chemical and cultural control has proven problematic and largely ineffective. To date, the planting of resistant clones appears to be the best means of controlling this pathogen. This project aims to generate and test transgenic hybrid poplar plants that carry candidate disease resistance genes and to identify key genes that are involved in the response to S. musiva infection. This project is funded by a USDA/AFRI Sustainable Bioenergy Research seed grant.
3. Developing yellow-poplar (Liriodendron tulipifera L.) as a new tree model research system for comparative genomics of secondary cell wall formation.
Also called tulip tree, tulip-poplar, yellow-poplar, white-poplar, and whitewood, L. tulipifera is one of the most attractive and tallest tree species of the eastern United States. L. tulipifera is rapid growing and a favored species among wood-using industries because of its vigorous response to intensive management, availability, high quality, and good working properties. In addition, this tree species is a member of the Magnoliaceae, a phylogenetically basal angiosperm group characterized by very slow rates of evolution since its divergence from monocots and eudicots, and is often chosen for molecular evolution studies as an out group to compare to more recently evolved taxa. This project aims to identify and functionally characterize genes involved in cell wall biosynthesis during wood formation (xylogenesis) in yellow-poplar and to conduct comparative genomic studies between Liriodendron and Populus. A genetic map is currently being constructed. Supported by an NSF Plant Genome Research program grant, we are in the process of construction the first genetic linkage map for L. tulipifera.
4. Modification of lignin by protein-crosslinking to facilitate production of biofues from poplar.
Lignin degradation is of critical importance in biomass utilization of woody plants, because the presence of lignin limits hydrolytic enzyme access to cellulose and hemicellulose. However, reducing lignin content without compromising tree fitness can be difficult. In this project, we hypothesize that by replacing even a small fraction of lignin-lignin linkages with peptide linkages, we will not compromise plant fitness but will facilitate the “cracking” of lignin such that the cellulosic components are more easily hydrolyzed. We try to alter the chemical nature of the lignin by introducing new peptide cross-links. Our research goal is to develop trees whose secondary cell walls exhibit little or no change in lignin quantity but whose wood will be more accessible to lignin extraction by pretreatment with proteases. This project was supported by US Department of Energy and Southeastern Sun Grant Center.
U.S. Department of Agriculture
An International Collaboration to Understand Molecular Mechanisms of Vegetative/Reproductive Transition in Gymnosperms
National Science Foundation
Comparative Genomics of Environmental Stress Responses in North American Hardwoods
U.S. Department of Agriculture
Genetic Engineering For Septoria Disease Resistance In Hybrid Poplar
Fundamental Genetics Laboratory
Special Topics in Genetics
Undergraduate Independent Research
Special Topics in Genetics
Xi (Victor) Xu, S.E. Schlarbaum, H Liang. Characterization of a cinnamyl alcohol dehydrogenase homolog in Liriodendron tulipifera. Submitted to Journal of Systematics and Evolution. 49 (5): 396–405.
H. Liang, S. Ayyampalayam, N. Wickett, A. Barakat, Y. Xu, L. Landherr, P. Ralph, T. Xu, S.E. Schlarbaum, J. H. Leebens-Mack, C.W. dePamphilis. Generation of a large-scale genomic resource for functional and comparative genomics in Liriodendron. Tree Genetics and Genome. DOI: 10.1007/s11295-011-0386-2. (In Press)
H. Liang, A. Barakat, S.E. Schlarbaum, J.E. Carlson (2011) Organization of the chromosome region harboring a FLORICAULA/LEAFY gene in Liriodendron. Tree Genetics and Genomes. 7: 373-384.
Y Jiao, N Wickett, S Ayyampalayam, A Chanderbali, L Landherr, PE Ralph, LP Tomsho, H Liang, PS Soltis, DE Soltis, S E Clifton, SE Schlarblum, SC Shuster, H Ma, J Leebens-Mack, CW dePamphilis. (2011) Phylogenomic detection of ancient polyploidy in seed plants and angiosperms. Nature 473:97–100
H. Liang, T. Zhebentyayeva, B. Olukolu, D. Wilde, G.L. Reighard, A. Abbott. (2010) Comparison of gene order in the chromosome region containing a Terminal Flowering1 homolog in apricot and peach reveals microsynteny across angiosperms. Plant Science 179: 390-398.
H. Liang, A. Barakat, S. E. Schlarbaum, D.F. Mandoli, J. Carlson (June, 2010) Comparison of gene order of GIGANTEA loci in yellow-poplar, monocots and eudicots. Genome 53:533-544.
H. Liang, P.A. Kumar, V. Nain, W.A. Powell, J.E. Carlson. (2010) Selection and Screening Strategies. In: C. Kole, C.H. Michler, A.G. Abbott and T.C. Hall (eds) Development and Deployment of Transgenic Plants. Springer-Verlag – Berlin, Heidelberg, New York, Tokyo, Vol. 1, pp. 85-143
Wall PK, Leebens-Mack J, Chanderbali A, Barakat A, Liang H, Landherr L., Tomsho LP, Hu Y, Carlson JE, Ma H, Schuster S, Soltis DE, Soltis PS, Altman N, and dePamphilis CW. (2009) Comparison of Next Generation sequencing technologies for de novo transcriptome characterization. BMC Genomics 10:347.
H Liang, CJ Frost, X Wei, NR Brown, JE Carlson, M Tien. (2008) Improved sugar release from lignocellulosic material by introducing a tyrosine-rich cell wall peptide gene in poplar. Clean-Soil, Air, Water 36 (8): 662-668
H Liang, JE Carlson, JH Leebens-Mack, PK Wall, LA Mueller, M Buzgo, LL Landherr, Y Hu, DS DiLoreto, DC Ilut, D Field, SD Tanksley, H Ma, CW dePamphilis. (2008) An EST Database for Liriodendron tulipifera L. floral buds: the first EST resource for functional and comparative genomics in Liriodendron. Tree Genet Genomes 4:419-433.
H Liang, E Feng, J Tomkins, K Arumuganathan, S Zhao, M Luo, D Kudrna, R Wing, J Banks, C dePamphilis, D Mandoli, S Schlarbaum, and JE Carlson. (2007) Development of a BAC library resource for yellow poplar (Liriodendron tulipifera) and the identification of genomic regions associated with flower development and lignin biosynthesis. Tree Genet Genomes 3: 215-225.
Newhouse AE, Schrodt F, Liang H, Maynard CA, Powell WA. (2007) Transgenic American elm shows reduced Dutch elm disease symptoms and normal mycorrhizal colonization. Plant Cell Rep 26: 977-87.