IBR   13079
INSTITUTO DE BIOLOGIA MOLECULAR Y CELULAR DE ROSARIO
Unidad Ejecutora - UE
capítulos de libros
Título:
Use of cyanobacterial proteins to engineer new crops
Autor/es:
MATIAS D. ZURBRIGGEN; NÉSTOR CARRILLO; MOHAMMAD R. HAJIREZAEI
Libro:
Recent Advances in Plant Biotechnology
Referencias:
Año: 2008;
Resumen:
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Cyanobacteria, the closest living relatives of the ancient endosymbiont
that gave origin to modern-day chloroplasts, offer a rich source of genes for
plant genetic engineering, due to both common and differential features with
the plant genetic systems. On the common side, cyanobacteria share many
metabolic pathways with plant cells and especially with chloroplasts, which may
be critical when the transgenic product needs to interact with endogenous
systems or substrates to exert its function. On the other hand, most mechanisms
involved in plant regulation of gene expression have arisen after
endosymbiosis, permitting a more rational manipulation of the introduced trait,
free from host regulatory networks. In addition, sequence divergence between
plant genes and their cyanobacterial orthologues prevents, in most cases, the
unwanted consequences of gene silencing and cosuppression. Finally, a few
cyanobacterial genes involved in tolerance to environmental and/or nutritional
stresses have disappeared from the plant genome during the evolutionary pathway
from cyanobacteria to vascular plants, raising the possibility of recovering
these adaptive advantages by introducing those lost genes into transgenic
plants. In spite of their obvious potential, the use of cyanobacterial genes to
engineer plants for increased productivity or stress tolerance has been
relatively rare. In this chapter, we review several examples in which this
approach has been applied to plant genetic engineering with considerable
success. They include modification of central metabolic pathways to improve
carbon assimilation and allocation by expressing unregulated cyanobacterial
enzymes, development of chilling tolerance by increasing desaturation of
membrane-bound fatty acids, pigment manipulation, shifts in light quality perception
and synthesis of ketocarotenoids not present in crops. Tolerance to adverse
environments could be achieved by introduction of cyanobacterial genes lost
from the plant genome during evolution, such as flavodoxin and cytochrome c6. The results obtained
illustrate the power of gene and data mining in cyanobacterial genomes as a
biotechnological tool for the design of transgenic plants with higher
productivity, enhanced tolerance to environmental stress and biofarming capabilities.