Stacking transgenes in forest trees.

Huge potential exists for improving plant raw materials and foodstuffs via metabolic engineering. To date, progress has mostly been limited to modulating the expression of single genes of well-studied pathways, such as the lignin biosynthetic pathway, in model species. However, a recent report illustrates a new level of sophistication in metabolic engineering by overexpressing one lignin enzyme while simultaneously suppressing the expression of another lignin gene in a tree, aspen. This novel approach to multi-gene manipulation has succeeded in concurrently improving several wood-quality traits.

[1]  Chung-Jui Tsai,et al.  Repression of lignin biosynthesis promotes cellulose accumulation and growth in transgenic trees , 1999, Nature Biotechnology.

[2]  A. Driessen,et al.  Precursor protein translocation by the Escherichia coli translocase is directed by the protonmotive force. , 1992, EMBO Journal.

[3]  W. Boerjan,et al.  Field and pulping performances of transgenic trees with altered lignification , 2002, Nature Biotechnology.

[4]  J. Gershenzon,et al.  Where will the wood come from? Plantation forests and the role of biotechnology. , 2002, Trends in biotechnology.

[5]  Scott A. Merkle,et al.  Development of transgenic yellow poplar for mercury phytoremediation , 1998, Nature Biotechnology.

[6]  G. Kishore,et al.  Metabolic engineering of Arabidopsis and Brassica for poly(3-hydroxybutyrate-co-3-hydroxyvalerate) copolymer production , 1999, Nature Biotechnology.

[7]  C. Halpin,et al.  Enabling technologies for manipulating multiple genes on complex pathways , 2001, Plant Molecular Biology.

[8]  S. Strauss,et al.  Forestry's fertile crescent: the application of biotechnology to forest trees. , 2003, Plant biotechnology journal.

[9]  C. Chapple,et al.  Modified lignin in tobacco and poplar plants over-expressing the Arabidopsis gene encoding ferulate 5-hydroxylase. , 2000, The Plant journal : for cell and molecular biology.

[10]  M. Fowler,et al.  Efficient Co-Transformation of Nicotiana Tabacum by two Independent T-DNAs, the Effect of T-DNA Size and Implications for Genetic Separation , 2001, Transgenic Research.

[11]  J. Ralph,et al.  Combinatorial modification of multiple lignin traits in trees through multigene cotransformation , 2003, Proceedings of the National Academy of Sciences of the United States of America.

[12]  M. Van Montagu,et al.  Agrobacterium tumefaciens transformation and cotransformation frequencies of Arabidopsis thaliana root explants and tobacco protoplasts. , 1998, Molecular plant-microbe interactions : MPMI.

[13]  T. Komari,et al.  Vectors carrying two separate T-DNAs for co-transformation of higher plants mediated by Agrobacterium tumefaciens and segregation of transformants free from selection markers. , 1996, The Plant journal : for cell and molecular biology.

[14]  Y. Poirier,et al.  Targeting of the polyhydroxybutyrate biosynthetic pathway to the plastids of Arabidopsis thaliana results in high levels of polymer accumulation. , 1994, Proceedings of the National Academy of Sciences of the United States of America.

[15]  B. Dobberstein,et al.  Common Principles of Protein Translocation Across Membranes , 1996, Science.

[16]  S. Strauss,et al.  The CP4 transgene provides high levels of tolerance to Roundup® herbicide in field-grown hybrid poplars , 2002 .

[17]  O. Olsson,et al.  Increased gibberellin biosynthesis in transgenic trees promotes growth, biomass production and xylem fiber length , 2000, Nature Biotechnology.

[18]  P. Beyer,et al.  Engineering the provitamin A (beta-carotene) biosynthetic pathway into (carotenoid-free) rice endosperm. , 2000, Science.

[19]  A. Séguin,et al.  Recent advances in the genetic transformation of trees. , 2001, Trends in biotechnology.

[20]  R. Jeffcoat,et al.  Production of a freeze–thaw-stable potato starch by antisense inhibition of three starch synthase genes , 2002, Nature Biotechnology.

[21]  N. Alder,et al.  Energetics of Protein Transport across Biological Membranes A Study of the Thylakoid ΔpH-Dependent/cpTat Pathway , 2003, Cell.

[22]  M. Van Montagu,et al.  T-DNA integration patterns in co-transformed plant cells suggest that T-DNA repeats originate from co-integration of separate T-DNAs. , 1997, The Plant journal : for cell and molecular biology.

[23]  J. Mol,et al.  Role of inverted DNA repeats in transcriptional and post-transcriptional gene silencing , 2000, Plant Molecular Biology.

[24]  Genomics, Genetic Engineering, and Domestication of Crops , 2003, Science.

[25]  Francisco M. Cánovas,et al.  Expression of a conifer glutamine synthetase gene in transgenic poplar , 1999, Planta.

[26]  T. Lehner,et al.  Generation and assembly of secretory antibodies in plants , 1995, Science.