pH effect on strain-specific transcriptomes of the take-all fungus

Area of Science:

• Plant Pathology
• Mycology
• Molecular Biology

Background:

• The soilborne fungus Gaeumannomyces tritici (G. tritici) causes the destructive take-all disease in wheat.
• Soil pH is a critical environmental factor influencing G. tritici's survival, growth, and pathogenicity.
• Intra-specific variations exist, with G. tritici strains showing preferential growth at acidic or neutral/alkaline pH.

Purpose of the Study:

• To investigate the genetic mechanisms underlying G. tritici's adaptation to different soil pH conditions.
• To compare the transcriptome of two G. tritici strains with distinct pH growth preferences under varying pH environments.
• To elucidate the role of differential gene expression in pH adaptation and pathogenesis.

Main Methods:

• Transcriptome sequencing of two G. tritici strains (PG6 and PG38) grown at acidic (pH 5.5) and neutral (pH 7.0) conditions.
• Differential gene expression analysis to identify genes regulated by pH and strain-specific responses.
• Comparative analysis of gene expression patterns related to metabolic pathways, cell proliferation, and stress resistance.

Main Results:

• Strain PG6, optimal at acidic pH, overexpressed cell proliferation genes under acidic conditions.
• Strain PG38, optimal at neutral pH, overexpressed genes involved in fatty acid and amino acid metabolism, and potential pathogenesis genes under neutral conditions.
• Strain PG38 also exhibited stress resistance gene expression across both pH conditions, indicating broader adaptability.

Conclusions:

• Differential expression of metabolic and virulence-associated genes contributes to G. tritici's adaptation to diverse soil pH environments.
• These adaptive strategies, including stress resistance, likely enhance the pathogen's success and survival in variable agricultural fields.
• Understanding these pH-dependent mechanisms offers insights into managing take-all disease in wheat.