Cloning and functional analysis of pbs2 gene in Aspergillus fumigatus / 中华微生物学和免疫学杂志

ABSTRACT

Objective To construct a mutant strain of Aspergillus fumigatus with the mutant pbs2 gene, and to investigate the effect of the mutant gene on the morphology of A. fumigatus, the variation of os-motic pressure and the sensitivity of oxidative stress. Methods S. cerevisiae pbs2 gene homologs was identi-fied in A. fumigatus genome database. A PCR fragment, composed of the 5' flanking sequence(approximate-ly 1 kb) ofpbs20RF and its 3' flanking sequence (approximately 1 kb), was subcloned into a vector pDHt/SK with Xho Ⅰ/Xba Ⅰ enzyme to produce a recombinant plasmid PA. The selected marker pryG amplified from pLAX223 was cloned into PA with BamH Ⅰ/Pst Ⅰ enzyme to produce plasmid PB. PB was transformed into Agrobacterium tumefac/ens and named plasmid At pbs2. Then At pbs2 was transformed into A. fumigatus strain AF293.1 (pyrG) via ATMT to produce the transformants △pbs2. To observe the growth rate and the phenotype on the MM containing different oxidative stress and osmotic pressure between the △pbs2 and the wild type. Results There were no visible difference between △pbs2 and AF293 on the radial growth rate and morphology. △pbs2 mutant was not only more sensitive to osmotic pressure produced by sodium chloride and glycerol but also sensitive to oxidative stress produced by hydrogen peroxide than the wild type. Conclu-sion The pbs2 gene plays a role in osmotic pressure and oxidative stress signal tmnsductions in A. fumiga-tus but only involved in oxidative stress induced by hydrogen peroxide specifically. However, pbs2 gene has a minor effect on growth and morphology in A. fumigatus.