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May 2, 2008
Source:
CropBiotech Update
There has been a growing
expectation that the biotech industry will deliver ‘second
generation’ transgenic crops in the near future. Unlike first
generation GM crops which involves manipulation of monogenic
traits, such as herbicide tolerance and insect resistance,
second generation crops will involve modification of traits
under the control of multiple genes such as stress resistance
and yield stability. Scientists involved in efforts to produce
these crops will greatly benefit from recent discoveries in the
field of genomics, including the availability of complete plant
genome sequences. Transcription factors (TFs), proteins that
regulate gene expression, are expected to be excellent
candidates for modifying complex traits in crop plants. A new
article published by the journal Plant Physiology reviews the
prospects for modification of crops by regulating these
transcription regulators.
Modifying the activity of TFs involved in photosynthesis may
lead to crops with increased yield. The same approach might be
exploited to develop plants that are disease tolerant, stress
resistant and nitrogen-use efficient. For instance, the HARDY
gene has recently been shown to enhance drought tolerance and
photosynthetic efficiency in transgenic rice. TF technologies,
however, often require optimization, either to reduce unwanted
side effects such as growth retardation or to enhance the
desired trait to the level at which it is of commercial value.
Read the article at
http://www.plantphysiol.org/cgi/content/full/147/1/20
| Source:
Plant
Physiology
Regulating the
Regulators: The Future Prospects for
Transcription-Factor-Based Agricultural
Biotechnology Products
Karen Century, T. Lynne Reuber and Oliver J.
Ratcliffe
Mendel
Biotechnology, Inc., Hayward, California 94545
It is now more than a decade since the first
commercially successful genetically engineered
agricultural crops were launched (Castle et al.,
2006). These first products were based in large part
on simple monogenic traits, such as herbicide
tolerance or insect resistance, which did not
require manipulation of complex molecular pathways
in the transgenic plant. Since then, there has been
a growing expectation that the biotechnology
industry will deliver a second generation of
transgenic products for more challenging traits
relating to yield and yield stability, which are
under complex polygenic control (Gutterson and
Zhang, 2004; Salmeron and Herrera-Estrella, 2006).
Advances in plant genomics and systems biology,
including the availability of the complete genome
sequences of both Arabidopsis (Arabidopsis thaliana)
and rice (Oryza sativa), have offered an
unprecedented opportunity to identify regulatory
genes and networks that control these important
traits. Because transcription factors (TFs)
naturally act as master regulators of cellular
processes, they are expected to be excellent
candidates for modifying complex traits in crop
plants, and TF-based technologies are likely to be a
prominent part of the next generation of successful
biotechnology crops. In this article, we review the
prospects for modification of these target traits by
TF regulation, including some of the challenges
associated with such a strategy. |
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