Plant Pathology Science

 Preventing plant disease damage requires the use of new, powerful, simple and portable tools to quickly diagnose pathogens. Today, biosensor technology  known as a powerful tool for evaluating conventional methods in agricultural sciences. Sensitivity, selectivity and portability of biosensors made it possible to develop them as special tools for rapid analysis of compounds in samples with low concentration. Biosensors have three main components, biological element, transducer and readout system. The most important application of biosensors in plant pathology is rapid detection of plant pathogens, in order to reduce the use of expensive and environmentally-damaging chemicals. This article introduces different types of biosensors and their applications in plant pathology.

Yellow mosaic, caused by the Barley Yellow Mosaic Virus (BaYMV), which is transmitted by the fungal-like organism Polymyxa graminis, is one of the most significant viral diseases affecting barley worldwide. To conduct serological and molecular surveillance of this virus in barley fields across Khorasan Razavi Province, northeastern Iran, a total of 86 leaf samples were collected in late winter of 2022. These samples were either randomly selected or exhibited symptoms such as mosaic patterns, chlorosis, and vein clearing. Upon transfer to the laboratory, the samples were analyzed using serological ELISA tests and molecular reverse transcription polymerase chain reaction (RT-PCR) assays. Using BaYMV-specific primers, an 800 base pair fragment corresponding to the viral coat protein was successfully amplified. Among the RT-PCR-positive isolates, the amplified DNA fragment from the Bajestan isolate was extracted from the gel and sequenced. The obtained sequence was verified using the BLAST program and subjected to phylogenetic analysis alongside other BaYMV coat protein sequences available in the NCBI GenBank database, using DNAMAN-7 and Vector NTI software. The sequenced fragment of the Bajestan isolate shared the highest nucleotide (94.79%) and amino acid (90.59%) similarity with a corresponding fragment from a European isolate. This study represents the first report of BaYMV occurrence in Bajestan County, Khorasan Razavi Province, Iran.