Cloning And Functional Analysis Of Gene BC1G₁2707.1 Related To Conidial Production In Botrytis Cinerea

A novel mutant BCt78 without ability of conidiation was found by screening the transformants of Botrytis cinerea and testified by PCR and Southern Bloting techniques. The flanking sequence of T-DNA insertion site was acquired by TAIL-PCR technology and then the T-DNA inserted gene speculated by BLAST between the flanking sequence and the known sequence in the B. cinerea gene bank. PCR and RT-PCR was used to confirm T-DNA insertion site and the mutant gene respectively. The function of the mutant gene was studied by assay of colony morphology, growth rate, cell wall degrading enzyme activity, the biological activity of the crude toxin and pathogenicity of the mutant strain on tomato leaves as well as expression of pathogenetic genes.The results are beneficial to further investigate molecular mechanism of conidiation as well as pathogenicity of Botrytis cinerea.1. T-DNA insertion site locates in the initiation codon of BC1G₁2707.1 gene. The mutant gene was identified as BC1G₁2707.1 by RT-PCR. The DNA full-length sequence of BC1G₁2707.1 was 135 bp, encoded a 44 amino acids hypothetical protein.2. The mutant strain colony was white, growed slowly,did not produce conidium and sclerotia on PDA medium,but showed the stronger pathogenicity to tomato leaves and increased cell wall degrading enzyme（ PG, PMG, Cx, PGTE and PMGE） activity and increased expression of pathogenetic genes such as cell wall degrading enzyme gene cutA, Bcp, genes （PKA1, PKA2, Bmp3, Bac） involved in signal pathway; gene（BcBOT2 ） encoding sesquiterpene synthase; gene（Lac1） encoding melanin and transmembrane protein gene Btp1 compared to the wild type strain.3. The BC1G₁2707.1 gene was involved in conidiation, sclerotia formation and pathogenicity in B. cinerea.