Brassinosteroid Enhances Resistance to Fusarium Diseases of Barley

• Published in: Phytopathology 2013-12, Vol.103 (12), p.1260-1267
• Main Authors: ALI, Shahin S, SUNIL KUMAR, G. B, KHAN, Mojibur, DOOHAN, Fiona M
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Biomass; Brassinosteroids - pharmacology; Disease Resistance; Fundamental and applied biological sciences. Psychology; Fusarium - physiology; Fusarium culmorum; Fusarium pathogens; Gene Expression Profiling; Gene Expression Regulation, Plant; Hordeum - drug effects; Hordeum - genetics; Hordeum - immunology; Hordeum - physiology; Hordeum vulgare; Host-Pathogen Interactions; Inflorescence - drug effects; Inflorescence - genetics; Inflorescence - immunology; Inflorescence - physiology; Oligonucleotide Array Sequence Analysis; Phytopathology. Animal pests. Plant and forest protection; Plant Diseases - immunology; Plant Diseases - microbiology; Plant Diseases - prevention & control; Plant Proteins - genetics; Plant Stems - drug effects; Plant Stems - genetics; Plant Stems - immunology; Plant Stems - physiology; Seedlings - drug effects; Seedlings - genetics; Seedlings - immunology; Seedlings - physiology; Seeds - drug effects; Seeds - genetics; Seeds - immunology; Seeds - physiology; Soil - chemistry; Time Factors; Triticum aestivum
• ISSN: 0031-949X; 1943-7684
• DOI: 10.1094/PHYTO-05-13-0111-R

Fusarium pathogens are among the most damaging pathogens of cereals. These pathogens have the ability to attack the roots, seedlings, and flowering heads of barley and wheat plants with disease, resulting in yield loss and head blight disease and also resulting in the contamination of grain with mycotoxins harmful to human and animal health. There is increasing evidence that brassinosteroid (BR) hormones play an important role in plant defense against both biotic and abiotic stress agents and this study set out to determine if and how BR might affect Fusarium diseases of barley. Application of the epibrassinolide (epiBL) to heads of 'Lux' barley reduced the severity of Fusarium head blight (FHB) caused by Fusarium culmorum by 86% and reduced the FHB-associated loss in grain weight by 33%. Growth of plants in soil amended with epiBL resulted in a 28 and 35% reduction in Fusarium seedling blight (FSB) symptoms on the Lux and 'Akashinriki' barley, respectively. Microarray analysis was used to determine whether growth in epiBL-amended soil changed the transcriptional profile in stem base tissue during the early stages of FSB development. At 24 and 48 h post F. culmorum inoculation, there were 146 epiBL-responsive transcripts, the majority being from the 48-h time point (n = 118). Real-time reverse-transcription polymerase chain reaction analysis validated the results for eight transcripts, including five defense genes. The results of gene expression studies show that chromatin remodeling, hormonal signaling, photosynthesis, and pathogenesis-related genes are activated in plants as a result of growth in epiBL.