Development of a qPCR method for detection and quantification of Ustilago nuda and COX1 gene in Barley seeds

Abstract: Barley loose smut caused by the fungal pathogen Ustilago nuda is a global concern with detrimental effects on barley production. Early detection of this infection is vital for effective disease supervision. However, current seed health testing protocols suffer from limitations in terms of time and efficiency. The present research work aimed to produce a method using qPCR for simultaneous screening of barley and U. nuda. A set of primers, 1F and 1R, was employed for the detection of rRNA operon internal transcribed spacer 1 sequence from U. nuda and a part of the COX1 gene, present in barley seeds, was selected as an internal control for comparison with U. nuda. A specific 79 bp target amplicon from a part of the COX1 gene was successfully amplified using COX1 F and COX1 R primers, and cloned into a vector for standard curve generation. However, attempts to replicate the previously published qPCR method by bachelor researcher for U. nuda internal transcribed spacer 1 sequence detection using 1F and 1R primers were unsuccessful. Several efforts were made to reproduce the results, but amplification was not observed. Further optimization, including literature review, primers and probe optimization is required to improve this method. The successful amplification of a part of the COX1 gene in both normal and infected samples underscore its potential as a reliable internal control. However, further research is necessary to refine the detection of U. nuda. This study underscores the need for continuous advancements in disease screening methodologies to meet global market demands.