Transcriptome analysis of mlo-mediated resistance in the epidermis of barley

• Published in: Molecular plant pathology Vol. 6; no. 2; pp. 139 - 151
• Main Authors: Zierold, U, Scholz, U, Schweizer, P
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01.03.2005; Blackwell
• Subjects: Agronomy. Soil science and plant productions; barley; Biological and medical sciences; Blumeria graminis; Blumeria graminis f. sp. hordei; complementary DNA; disease resistance; epidermis (plant); Erysiphe graminis f. sp. hordei; Fundamental and applied biological sciences. Psychology; gene expression regulation; Genetics and breeding of economic plants; Hordeum vulgare; messenger RNA; Pest resistance; Plant pathogens; powdery mildew; resistance mechanisms; transcriptome; Varietal selection. Specialized plant breeding, plant breeding aims; Monocotyledones; Plant pathogen; Hordeum vulgare; Epidermis; Cereal crop; Fungus resistance; Fungi; Messenger RNA; Gramineae; Angiospermae; Ascomycetes; Spermatophyta; Erysiphe graminis f. hordei; Thallophyta
• ISSN: 1464-6722; 1364-3703
• DOI: 10.1111/j.1364-3703.2005.00271.x

SUMMARY The shoot epidermis of plants is of prime importance for host and non‐host defence against a large number of fungal diseases, including powdery mildew of barley, caused by Blumeria graminis (DC.) E.O. Speer f.sp. hordei. In order to understand better the mechanisms within the epidermis leading to susceptibility as well as durable host resistance, we characterized the transcriptome of two Blumeria‐attacked, near‐isogenic barley lines of cv Ingrid differing in the presence or absence of the mlo5 resistance gene. A cDNA array was established containing 3128 unique sequences from pathogen‐attacked, resistant barley epidermis, which was hybridized with cDNA probes from pathogen‐challenged epidermis. Expression analysis resulted in the identification of 311 candidate genes that were differentially expressed in a reproducible manner between control and inoculated epidermis. Among the up‐regulated genes were 18 of fungal origin. The amplitude of differential host gene expression was generally higher in the presence of the mlo5 resistance gene as compared with a susceptible interaction. This suggests that mlo‐mediated resistance is based on multiple defence compounds and mechanisms once pathogen‐derived molecular patterns have been recognized, which yields a possible explanation for the durability of the phenomenon in the field.