Heat Pre-Treatment Modified Host and Non-Host Interactions of Powdery Mildew with Barley Brassinosteroid Mutants and Wild Types

• Published in: Life (Basel, Switzerland) Vol. 14; no. 1; p. 160
• Main Authors: Rys, Magdalena, Saja-Garbarz, Diana, Fodor, József, Oliwa, Jakub, Gullner, Gábor, Juhász, Csilla, Kornaś, Andrzej, Skoczowski, Andrzej, Gruszka, Damian, Janeczko, Anna, Barna, Balázs
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 01.01.2024
• Subjects: Acids; Agricultural research; Airborne microorganisms; Antifungal agents; Barley; Biosynthesis; Blumeria graminis; Blumeria hordei; Brassinosteroids; Chlorophyll; chlorophyll a fluorescence; Climate change; Cultivars; Deficient mutant; Development and progression; Diseases and pests; Fluorescence; Genetic aspects; Genetically modified crops; Genotypes; Global temperature changes; Health aspects; Health services; Heat; Heat resistance; Heat shock; Heat treatment; Heat treatments; High resistance; High temperature; Hormones; Host plants; Hypersensitive response; leaf spectral reflectance; Leaves; Light microscopy; Medical research; Medicine, Experimental; Microscopy; Mutation; near-isogenic lines; Optical microscopy; Papillae; pathogen inoculation; Pathogens; Physiological aspects; Plant diseases; Plant resistance; Plant-pathogen relationships; Powdery mildew; Powdery mildew diseases; Pretreatment; Risk factors; Seeds; Signs and symptoms; Steroid hormones; Wheat; Poland; Blumeria graminis; chlorophyll a fluorescence; near-isogenic lines; leaf spectral reflectance; pathogen inoculation; Blumeria hordei
• ISSN: 2075-1729; 2075-1729
• DOI: 10.3390/life14010160

High temperatures associated with climate change may increase the severity of plant diseases. This study investigated the effect of heat shock treatment on host and non-host barley powdery mildew interactions using brassinosteroid (BR) mutants of barley. Brassinosteroids are plant steroid hormones, but so far little is known about their role in plant-fungal interactions. Wild type barley cultivar Bowman and its near-isogenic lines with disturbances in BR biosynthesis or signalling showed high compatibility to barley powdery mildew race A6, while cultivar Delisa and its BR-deficient mutants 522DK and 527DK were fully incompatible with this pathogen (host plant-pathogen interactions). On the other hand, Bowman and its mutants were highly resistant to wheat powdery mildew, representing non-host plant-pathogen interactions. Heat pre-treatment induced shifts in these plant-pathogen interactions towards higher susceptibility. In agreement with the more severe disease symptoms, light microscopy showed a decrease in papillae formation and hypersensitive response, characteristic of incompatible interactions, when heat pre-treatment was applied. Mutant 527DK, but not 522DK, maintained high resistance to barley powdery mildew race A6 despite heat pre-treatment. By 10 days after heat treatment and infection, a noticeable shift became apparent in the chlorophyll fluorescence and in various leaf reflectance parameters at all genotypes.