Chitinase Activities in Wheat and Its Relative Species

Defense components such as chitinases (EC 3.2.1.14) are crucial for plants to cope diseases. Despite of that the pattern and activities of these enzymes in agronomically important Triticale is unexplored. This work is aimed to study chitinase activities in the leaves of plants of early developmental stages in two diploids (Aegilops tauschii Coss., Triticum monococcum L.), four tetraploids (Ae. cylindrical Host, Ae. triuncialis L., T. araraticum Jakubyz, T. dicoccum Schrank) and two hexaploids (T. aestivum L., T. spelta L.). The leaves were subjected to quantitative and qualitative activity assays using synthetic 4-methylumbelliferyl-β-D-N,N´,N´´-triacetylchitotrioside and glycolchitin as substrates, respectively. Our results showed that the activities of chitinases with specificity towards short oligomers were variable and genotype dependent. The enzyme activities in the tetra- and hexaploid genotypes were significantly higher than in diplod counterparts. In the gel detection assays were revealed up to four fractions (~20, 30, 42 and 95 kDa) of proteins with the chitinase activity towards long chain polymers. The isoform of ~30 kDa was identified in all analyzed genotypes. Among the seven acidic and three basic chitinase fractions identified, three acidic (ChiA, ChiB, ChiC) and two (ChiH, ChiI) fractions were present in all genotypes. None of the isoforms can be assigned as specific with respect to ploidy.