Biomedical Engineering Reference
In-Depth Information
202 pathogenicity genes into three main categories: (i) those that affect the
vegetative growth phase, (ii) those that govern asexual reproduction and
(iii) those that are involved in the infection phase. Within the vegetative
phase, there are genes that distinctively affect growth rate, pigmentation and
conidial germination. Among the genes that govern asexual reproduction,
there are genes that specifi cally affect conidiation and conidial morphology.
Finally, in the infection stage, there are genes that control appressorium
formation, penetration and invasive growth of the fungus. This is the
largest individual study conducted thus far and therefore constitutes a
large number of fungal pathogenicity genes including new/novel genes
published so far. Subsequently, targeted disruption of 15 pathogenicity-
defective mutants ORF confi rmed the association between the T-DNA
insertion and the observed phenotypes.
CONCLUSION
ATMT method has been developed in a large number of fungal species
including many phytopathogens as a basic transformation tool for genetic
manipulation. Employment of ATMT in
M. oryzae
for large-scale insertional
and targeted mutagenesis has identifi ed several important pathogenicity
genes and established it as a model system for fi lamentous fungi. Thus,
the utilization of this technique in other fungal systems including
V.
dahliae
for decoding myriad genes and their function is gaining popularity.
Most importantly, using large-scale insertional mutagenesis in
M. oryzae
,
several genes required for pigmentation, conidiation, conidia germination,
appressorium formation, penetration and invasive growth have been
characterized. In
V. dahliae
, a few genes-associated with pigmentation,
conidia production, microsclerotia development and pathogenicity have
been characterized. The availability of genomes for these two fungi will
undoubtedly facilitate the identifi cation of T-DNA insertional site, gene
information and their function. Similar to
M. oryzae
, the industrial-scale
approach is needed for several other fungi especially for economically
important pathogens for which genome sequence information is currently
available to better understand the pathogen biology. Furthermore,
ATMT is also being used for monitoring GFP expression, the temporal
and spatial expression patterns in tagged interested genes. The ATMT
method will continue to play a major role in the next stage of fungal
genomics to elucidate gene functions that undoubtedly will advance our
understanding of plant-microbe interactions.
