Powdery Mildew-Induced Hormonal and Photosynthetic Changes in Barley Near Isogenic Lines Carrying Various Resistant Genes

• Published in: International journal of molecular sciences 2020-06, Vol.21 (12), p.4536
• Main Authors: Saja, Diana, Janeczko, Anna, Barna, Balázs, Skoczowski, Andrzej, Dziurka, Michał, Kornaś, Andrzej, Gullner, Gábor
• Format: Article
• Language: English
• Subjects: Apoptosis; Ascomycota - drug effects; Ascomycota - pathogenicity; Auxins; Barley; Carotenoids; Cereals; Chlorophyll; Chlorophyll A - metabolism; Cultivars; Cytokinins; Disease; Disease Resistance - genetics; Fluorescence; Fungi; Fungicides; Gene Expression Regulation, Plant - genetics; Genes; Genotypes; Gibberellins; Homeostasis; Hordeum - genetics; Hordeum - metabolism; Inoculation; Leaves; Moisture content; Pathogens; Photosynthesis; Photosynthesis - physiology; Photosystem II; Physiology; Plant Diseases - genetics; Plant Leaves - metabolism; Plant Proteins - metabolism; Powdery mildew; Reflectance; Signs and symptoms; Water content
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms21124536

The present work focused on the characterization of some physiological mechanisms activated upon powdery mildew inoculation of the susceptible barley cultivar Ingrid and its near-isogenic lines (NILs) carrying various resistant genes ( , and ). After inoculation with f. sp. ( ), measurements of leaf reflectance and chlorophyll fluorescence were performed 3 and 7 day post-inoculation (dpi), while hormone assays were made 7 dpi. -inoculated resistant genotypes were characterized by lowered leaf reflectance parameters that correlated with carotenoids (CRI) and water content (WBI) in comparison to inoculated Ingrid. The PSII activity (i.e., Fv/Fm, ETo/CSm and P.I. ) strongly decreased in susceptible Ingrid leaves when the disease symptoms became visible 7 dpi. In Mla plants with visible hypersensitive spots the PSII activity decreased to a lesser extent. Inoculation resulted in a very slight decrease of photosynthesis at later stage of infection in Mlg plants, whereas in resistant mlo plants the PSII activity did not change. Chlorophyll fluorescence measurements allowed presymptomatic detection of infection in Ingrid and Mla. Changes in the homeostasis of 22 phytohormones (cytokinins, auxins, gibberellins and the stress hormones JA, SA and ABA) in powdery mildew inoculated barley are discussed in relation to resistance against this biotrophic pathogen.