Revue internationale de recherche et développement en pharmacie et sciences de la vie

Abstrait

THE ROLE OF CHITINASE IN THE PATHOGENICITY OF LECANICILLIUM LECANII BASED ON GENETIC ENZYMATIC ANALYSIS AND BIOASSAY AGAINST NYMPH POD SUCKING BUG RIPTORTUS LINEARIS

Yayuk Mulyati, Toto Himawan, Estri Laras Arumingtyas and Abdul Latief Abadi

Objectives: The research aimed to evaluate the role of chitinase in the pathogenicity of Lecanicillium lecanii based on comprehensive analysis of mutation occurences in the partial sequence of Chit1 gene, comparison and correlation of chitinase production and pathogenicity between wild type and mutant.
Methods: Mutation was conducted using ultraviolet-C radiation (UV-C) with the period of exposure of 0, 2 (UV-C2), and 4 (UV-C4) hours. Genomic DNA was isolated using NucleoSpin Plant II kit, and then was PCR-sequenced, and the sequencing result of wild type and mutant was analysis for their alignment. Chitinase production were analyzed using Schales methods. Pathogenicity of wild type and mutant tested against nymphs pod sucking bug Riptortus linearis in laboratory conditions.
Results and Conclusions: The results showed that UV radiation caused mutations of partial sequence of Chit1 genes. The mutation occurences in the mutant UV-C2 is 2.47 times higher than mutant UV-C4. Wild type and mutant showed significantly different chitinase secretion. Chitinase production in mutant UV-C2 and mutant UVC4 were 1.003 and 1.012 fold higher than wild type, respectively. The higher ability of mutant to produce chitinase compared to wild type was not followed by their pathogenicity. The mortality of R. linearis nymph was higher when it was infected by wild type compared to mutant. The wild type and mutant showed no difference in their pathogenicity in the sixth and tenth days of observation. Evaluation of the overall findings of these study lead to the conclusion that chitinase is not the most important hydrolytic enzyme in the pathogenicity of L. lecanii.