Comparative Transcriptome Profiling of var. in Wheat Roots in the Absence and Presence of Biocontrol CC09.

This study aimed to explore potential biocontrol mechanisms involved in the interference of antagonistic bacteria with fungal pathogenicity . To do this, we conducted a comparative transcriptomic analysis of the "take-all" pathogenic fungus var. () by examining -infected wheat roots in the presence or absence of the biocontrol agent CC09 () compared with grown on potato dextrose agar (PDA) plates. A total of 4,134 differentially expressed genes (DEGs) were identified in -infected wheat roots, while 2,011 DEGs were detected in +-infected roots, relative to the grown on PDA plates. Moreover, 31 DEGs were identified between wheat roots, respectively infected with and +, consisting of 29 downregulated genes coding for potential pathogenicity factors - e.g., para-nitrobenzyl esterase, cutinase 1 and catalase-3, and two upregulated genes coding for tyrosinase and a hypothetical protein in the +-infected roots when compared with the -infected roots. In particular, the expression of one gene, encoding the ABA3 involved in the production of 's hormone abscisic acid, was 4.11-fold lower in -infected roots with than without . This is the first experimental study to analyze the activity of transcriptomes in wheat roots exposed or not to a biocontrol bacterium. Our results therefore suggest the presence of directly and/or indirectly impairs the pathogenicity of in wheat roots through complex regulatory mechanisms, such as hyphopodia formation, cell wall hydrolase, and expression of a papain inhibitor, among others, all which merit further investigation.