Expression and promoter characterization of BbPacC, a pH response transcription factor gene of the entomopathogenic fungus Beauveria bassiana.

To survive, the entomopathogenic fungus Beauveria bassiana, which shows promise as a biocontrol agent for a variety of pests, including agricultural and forestry pests and vectors of human pathogens, must tailor gene expression to the particular pH of its environment. The pH response transcription factor gene BbPacC and its flanking sequence were cloned from this fungus. Quantitative reverse transcription (RT)-PCR revealed that it is highly induced by alkaline pH and salt stress, and the expression level achieved twice that of the housekeeping gene γ-actin.

Selection of optimal reference genes for expression analysis in the entomopathogenic fungus Beauveria bassiana during development, under changing nutrient conditions, and after exposure to abiotic stresses.

The selection of suitable reference genes is crucial for accurate quantification of gene expression. To identify suitable reference genes in Beauveria bassiana, the expression of 14 candidates (18S, 28S, β-Tub, GAPD, γ-Act, TEF, HGPT, His3, His2A, TBP, CypA, CypB, PP1, and CrzA) was measured by quantitative polymerase chain reaction at different development stages and under various nutritional and stress conditions. Expression stability, as evaluated by the geNorm and NormFinder programs, revealed that His2A/γ-Act/CrzA was the most stably expressed set of genes throughout development, while 28S/PP1/CypA and His2A/γ-Act/CypA were the most stably expressed gene sets under a variety of nutritional and stress conditions, respectively.