The effect of extra copies of sho 1 or pbs 2 gene on the adaptive ability of Aspergillus fumigatus to several stresses

Abstract

Abstract: Objective To explore the role of extra copies of sho 1 or pbs 2 in resistance to hyperosmotic stress,oxidative stress, cell wall stress and alkaline pH stress in A. fumigatus.Methods The reconstructed plasmid harboring a sho 1 gene or a pbs 2 gene were transformed into A. fumigatus by using protoplast transformation method and the resulting strains were designated MCsho1 or MCpbs2. RT-PCR was used to detect the expression levels of sho 1 in MCsho1 and pbs 2 in MCpbs2 strains. Then strains harboring extra copies as well as sho 1 and pbs 2 deleted mutants were treated with NaCl, H₂O₂, Congo red and alkaline pH stresses and the resistance phenotypes were observed.Results Mutants harboring extra copies of sho 1 or pbs 2 showed higher expression levels of sho 1 or pbs 2 respectively. Extra copies of sho 1 or pbs 2 conferred resistance to NaCl (1 mol/L), H₂O₂ (5 mmol/L), Congo red (400 mg/L)or alkaline pH (10.0)stress.sho 1 and pbs 2 deleted mutants showed higher sensitivity to NaCl (1 mol/L),H₂O₂ (5 mmol/L)and alkaline pH (10.0)stress than the wild strain. △pbs 2 deleted mutant showed similar sensitivity to Congo red (400mg/L) compared to the wild strain.Conclusion Extra copies of sho 1 or pbs 2 conferred resistance to hyperosmotic stress, oxidative stress, cell wall stress and alkaline pH stress in A. fumigatus.

Key words: Aspergillus fumigatus, sho 1, pbs 2, Hyperosmotic stress, Oxidative stress, Congo red, Alkaline pH

CLC Number:

R379.6

MA Dong-mei, JI Ya-juan, YANG Fang, LIU Wei, WAN Zhe, LI Ruo-yu. The effect of extra copies of sho 1 or pbs 2 gene on the adaptive ability of Aspergillus fumigatus to several stresses[J]. Chinese Journal of Mycology, 2012, (4): 193-198.

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