Cloning of a novel chitinase gene TIChi46 from Trichoderma longibrachiatum parasitizing on Meloidogyne incognita eggs
A fungus named HBF1 was isolated from female of M.incognita on tobacco in Hubei province, China and was identified as Trichoderma longibrachiatum based on morphological characteristics and molecular analysis of rDNA-1TS coupled with translation elongation factor 1-alpha.To identify virulent factors and elucidate the parasitic mechanism on M.incognita eggs, the egg parasitism of M.incognita eggs by T.longibrachiatum HBF1 was investigated in vitro.The percentage of parasitized eggs was 80.45％ at the 10 th day after inoculation.From this isolate, the novel genomic and cDNA clones encoding chitinase have been cloned using the degenerate PCR primers and RACE techniques.The analysis of the gene and the deduced amino acid sequence along with its phylogeny analysis was by biology software.Results showed that HBF1 was able to penetrate nematode egg and produce chitinase, maximum activity of chitinase was 24.88 μmol/h/mL recorded at the tenth day after inoculation.We have cloned a novel chitinase gene TlChi46 from T.longibrachiatum HBF1 for the first time.The gene is 1 793 bp in length and contains three putative introns.The ORF of TlChi46 is 1 272 bp in size with encoding protein of 423 aa , molecular mass of 45.9 kDa and pI of 5.23.Phylogeny analysis reveals that this chitinase and other reported Trichoderma spp.chitinases are clustered together and are phylogenetically distant from other entomopathogenic fungi.These results demonstrated that the amino acid sequence coded by chitinase gene TlChi46 from T.longibrachiatum HBF1 possesses promising functional domains for the further research, T.longibrachiatum HBF1 with the the strong chitinolytic and egg-parasitic activity has a great biocontrol potential against M.incognita.
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万方数据
维普
