Conventional detection and quantification real-time PCR of the pks-1 gene of Chaetomium globosum

Abstract

Chaetomium globosum is known as a potential biocontrol indicator against various soil and seedborne pathogens. Precise data are necessary for population monitoring of C. globosum for its effective use in agriculture. A sequence-characterized amplified region marker has been applied for the detection of this biocontrol agent, which will help to detect C. globosum at the site of its application. Out of 17 isolates of C. globosum, only 8 isolates of C. globosum amplified a monomorphic band of 1,900 bp. C. globosum is known for producing chaetoglobosin A. The pks-1 gene is unique in C. globosum in that it is involved in chaetoglobosin A production, melanin formation, and sporulation. Real-time PCR of pks-1 was used to compare the expressions of the pks-1 gene and chaetoglobosin A biosynthesis and sporulation. It was found that the sporulation of C. globosum was associated with the levels of pks-1 gene expression; Cg2 isolate showed high expression of the pks-1 gene, 41.21%, and also produced a great number of spores and perithecia. The association between the pks-1 gene expression and chaetoglobosin A production was estimated. The Pks-1 gene was expressed by all C. globosum isolates except one isolate, C1, which is another species of Chaetomium. In addition, all C. globosum isolates produced chaetoglobosin A with different concentrations and did not express the same levels of pks-1. This finding may be a result of the solvent type used in the extraction.

Keywords: Chaetomium globosum; SCAR marker; pks-1 gene.