Page 181 - Advances in Textile Biotechnology

162 Advances in textile biotechnology

regulation associated with fibre formation. In addition, a better understand-

ing of the genomes of fibre species also allows us to integrate knowledge
obtained from studies on model plants. Recent advances in whole genomic,
transcriptomic and proteomic approaches have enabled us to gain a much
better idea of the genes involved in a wide range of different biological
processes in both animals and plants (Harismendy et al., 2009; Lister et al.,

2009), and such strategies are now being adapted for fibre plants. For
example, recent transcriptomic and proteomic analyses have been used to
gain an overview of the genes and proteins potentially involved in fi bre
formation in cotton (Hovav et al., 2008; Shi et al., 2006), hemp (De Pauw
et al., 2007; van den Broeck et al., 2008) and flax (Roach and Deyholos, 2007;

2008). For genomic data (i.e. sequencing the genome of a plant), fi bre plants
are no exceptions and an international consortium exists to sequence the
cotton genome (Chen et al., 2007) and the sequencing of the fl ax genome
is currently underway (Deyholos, personal communication).
Having ‘catalogued’ the different genes present, the next challenge is to
find out the role of these genes in the formation and development of fi bres.

Such information can be obtained by comparing what is known about the
corresponding genes (orthologs) in other model plant species (Arabidopsis,
poplar, tobacco). In addition both forward- and reverse-genetics can be
used to determine the role of different genes. For example, high-throughput
screening of chemical mutant populations has proved to be an extremely
useful tool to identify plants showing modified phenotypes, thereby allow-

ing identification of the gene associated with the observed modifi cation
(Martin et al., 2009; Perry et al., 2009). Although some natural and induced

mutants in fibre plants are known (Bretagne-Sagnard et al., 1996; Roland,
1991; Sengupta and Palit, 2004), it is only recently that high-throughput

screening of large-scale populations of fibre plants such as flax has been
developed (Deyholos, personal communication; Hawkins, 2009). Interest-
ingly, as already done in the case of bioenergy research (saccharifi cation),
mutant populations could also be screened against various fi bre processing
enzymes in order to identify plants showing increased sensitivity/resistance.
Complete understanding of a given gene’s role in a particular biological

process (such as fibre wall formation and development) will also require

the development of a ‘systems biology’ approach in fibre species and involv-
ing the integration of transcriptomics, proteomics and metabolomics (Saito
et al., 2007; Yuan et al., 2008).
Finally, another extremely important aspect concerns the impact of
environmental conditions on cell wall structure (and hence fi bre quality).
For example, in maize, it has been shown that water stress provokes changes
in lignin synthesis, as well as in cell wall proteins associated with cell expan-
sion (Fan et al., 2006, Muller et al., 2007). Similarly, soil pollutants such as
the heavy metal cadmium have been shown to modify cell wall structure in

© Woodhead Publishing Limited, 2010