32 research outputs found
Evolution and isoform specificity of plant 14-3-3 proteins
The 14-3-3 proteins, once thought of as obscure mammalian brain proteins, are fast becoming recognized as major regulators of plant primary metabolism and of other cellular processes. Their presence as large gene families in plants underscores their essential role in plant physiology. We have examined the Arabidopsis thaliana 14-3-3 gene family, which currently is the largest and most complete 14-3-3 family with at least 12 expressed members and 15 genes from the now completed Arabidopsis thaliana genome project. The phylogenetic branching of this family serves as the prototypical model for comparison with other large plant 14-3-3 families and as such may serve to rationalize clustering in a biological context. Equally important for ascribing common functions for the various 14-3-3 isoforms is determining an isoform-specific correlation with localization and target partnering. A summary of localization information available in the literature is presented. In an effort to identify specific 14-3-3 isoform location and participation in cellular processes, we have produced a panel of isoform-specific antibodies to Arabidopsis thaliana 14-3-3s and present initial immunolocalization studies that suggest biologically relevant, discriminative partnering of 14-3-3 isoforms
Biotechnological Means for Genetic Improvement in Castor Bean as a Crop of the Future
Not AvailableProfitable cultivation of castor bean is beset
with problems of vulnerability of cultivars and
hybrids to a multitude of insect pests and
diseases. The presence of the toxic proteins
ricin and hyperallergenic Ricinus communis
agglutinin (RCA) in the endosperm restricts
the use of deoiled seed cake as cattle feed.
Due to this crop’s low genetic diversity,
genetic engineering can be an efficient
approach to introduce resistance to biotic
and abiotic stresses as well as seed quality
traits. Recently, castor oil gained attention as a
sustainable second-generation feedstock for
biojet fuel that would reduce carbon dioxide
emissions. Because of a growing interest in
castor oil as a biofuel and the presence of the
powerful toxin ricin in its seed, metabolic
pathways and regulatory genes involved in
both oil and ricin production have been
analyzed and characterized. Genetic engineering
of castor bean offers new possibilities to
increase oil yield and oxidative stability,
confers stress tolerance, and improves other
agronomics traits, such as reduced plant
height to facilitate mechanical harvesting.
However, difficulties in tissue culture-based
regeneration and poor reproducibility of results are major bottlenecks for genetic
transformation of castor bean. Despite
advances in tissue culture research over the
past four decades, direct or callus-mediated
adventitious shoot regeneration systems that
are genotype-independent remain a much
sought-after goal in castor bean. Genetic
transformation attempts to develop insect resistant
and ricin-free transgenic castor bean
lines have been based on shoot proliferation
from meristematic tissues. This chapter
describes new transformation methods under
development and the progress achieved so far
in genetic engineering of castor bean for
agronomically desirable attributes.Not Availabl