Physiology and Molecular Biology of Stress ... - KHAM PHA MOI

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A.K. Tyagi, S. Vij and N. Saini
yeast, a proteome chip has been constructed using 5800 proteins and screened for
their ability to interact with proteins and phospholipids (Zhu et al., 2001).
Yeast two hybrid system can also be used for determining protein-protein
interactions (Field and Song, 1989). Yeast clones containing ORFs are fused to DNA
binding or activation domains, whereby proteins encoded by ORFs interact in the cell
nucleus. ORF clones are then identified by sequencing. Large-scale analysis with array
is also carried out. Such arrays are probed with single ORF DNA binding domain
fusions. The surviving colonies on the basis of nutritional selection identifies the
interacting proteins which can be sequenced directly. The hybrid system can be automated
and provides a high throughput technique for studying protein interactions
(Walhout and Vidal, 2001).
Proteomics-based research is proving helpful in characterization of stressrelated
proteins and identification of corresponding novel stress-responsive genes for
production of stress tolerant plants.
6. RESOURCE FOR FUNCTIONAL GENOMICS
The efforts to understand gene function by individual groups can never gain the required
momentum for large-scale functional genomics till there is a true sharing of
resources amongst the scientific community. This would be made possible by putting
the resources into easy-to-use, well-catalogued and freely accessible databases to the
research community. A large number of databases are now available for public use
containing details of mutant collections and EST/cDNA sequences to facilitate the task
of functional analysis (Tables 3 and 4).
The Arabidopsis Information Resource (TAIR) is the most well integrated
platform for Arabidopsis researcher’s world wide including data contributed by over
11,000 researchers and 4,000 organizations available at http://arabidopsis.org (Rhee,
2000; Rhee et al., 2003). This site not only provides the details of Arabidopsis genome
sequence but also information regarding annotation, gene families, maps, markers, polymorphisms,
protein information, metabolic pathways and gene expression data as well
as seed and DNA stocks. The data available at TAIR includes around 400,000 nucleotide
sequences, 200,000 mutant lines, 400 genetic markers, 90,000 polymorphisms and
data from more than 600 microarray experiments (Garcia-Hernandez et al., 2002). Keeping
pace with the completion of the rice genome sequence, several databases are available
for rice functional genomics too. These include the Rice Genome Program (RGP,
Japan; http://rgp.dna.affrc.go.jp/); Arizona Genomics Institute (AGI; http://
www.genome.arizona.edu/); The Institute of Genomic Research Rice Database (TIGR;
www.tigr.org/tdb/rice), International Rice Information System (IRIS; www.iris.irri.org)
and Oryzabase (http://www.shigen.nig.ac.jp/rice/ oryzabase/top.jsp). The Rice Genome
Research Center (RGRC), established by the National Institute of Agrobiological Sciences,
Japan in 2003 is accessible through RGP’s site. This site provides access to
~50,000 Tos17 insertion lines of rice and flanking sequences of 5,000 lines. It also