PCR-Diagnostic of Septoria nodorum Berk. Aggresivenes in Wheat Tissue - Biotechnology of Fungal Genes - page 294

Figure 4. The results of PCR analysis size of CDA gene (1-9) and ITS fragment (10-16)
amplifi cation with use of DNA from fungi S. tritici (1, 10), B. bossinana (2, 11), U. tritici
(3, 12), B. sorokiniana (4, 13), F. culmorum (5, 14), T. caries (6, 15), S. nodorum (7, 16). PCR
amplifi cation of S. nodorum CDA gene from infected (8) and not infected (9) wheat leaves.
(10 hr after infection). M - marker of DNA molecular weights.
Thus, the PCR method with primers for the CDA gene, allows us to
diagnose the fungus S. nodorum in the infected tissues of wheat with high
accuracy. Since the glume blotch begins to appear visually by the 4th
day after inoculation and only on the leaves, then using the developed
DNA diagnosis, as we assume, we can identify the latent form of the
disease in wheat plants, for example, in the early phases of fungus
development in the caryopsis of wheat and in the absence of sporulation
in fi eld infection.
Unfortunately, by means of PCR, which are using DNA fragments
of the fungus it is diffi cult to talk about the degree of aggressiveness of
individual strains of fungus. At the same time, judging by CDA activity
which was higher in the aggressive strain than in less aggressive ( Figure 2
and 3), the enzyme activity is closely connected with the manifestation of
the aggressiveness of fungi in the future. Probably, in these conditions, the
modifi ed methods of RT-PCR with fi xation data in the real time (Oliver et al.
2008) or the end-point of amplifi cation, can be used for the purposes set out
in this work. Figure 5 shows the results of CDA gene expression activity, in
strains fungus S. nodorum —4VD, 6VD, 9MN and Bas1, normalized relative
to gene activity TUB . As it can be seen the transcriptional activity of a CDA
gene is higher in the aggressive strains of the fungus in comparison with
less aggressive.
CONCLUSION
Thus, the connection between the results of CDA gene expression and
the degree of disease development on wheat leaves, as well as with