Cell Wall Structural Features Underlying Maize Resistance to Fusarium graminearum
Penélope García-Angulo (Spain)1 2; Alba Manga-Robles (Spain)1; Diego Rebaque (Spain)1 2 3 4; Pilar Carrancio-Jato (Spain)1 2; Antonio Encina García (Spain)1 2; Rogelio Santiago (Spain)5; Francisco Javier Vilaplana Domingo (Sweden)6 3;
1 - 1Área de Fisiología Vegetal, Departamento de Ingeniería y Ciencias Agrarias, Universidad de León, León, Spain; 2 - 2Institute of Molecular Biology, Genomics and Proteomics (INBIOMIC), Universidad de León, Campus de Vegazana, 24071 León, Spain; 3 - 4KTH FOOD, KTH Royal Institute of Technology, Brinellvägen 8, SE-100 44 Stockholm, Sweden; 4 - 5Universidad Politécnica de Madrid, Madrid, Spain; 5 - 6Misión Biológica de Galicia, Sede de Pontevedra (CSIC). Pazo de Salcedo. Carballeira 8, 36143 Salcedo, Pontevedra, Spain; 6 - 3Division of Glycoscience, Department of Chemistry, KTH Royal Institute of Technology, AlbaNova University Centre, SE-106 91, Stockholm, Sweden;
Keywords: stalk rot disease; cell wall; Zea maize;
Abstract Topics: Theme 9: Cell Wall Function and Signaling in plant adaptation to Biotic and Abiotic Stresses
Type of Presentation: Poster

Abstract text: Fusarium graminearum is a fungal pathogen capable of degrading pith cell walls and colonizing other maize tissues, causing stalk rot disease and consequently reducing crop yield and quality. This study aimed to investigate genotypic differences between two maize inbred lines with contrasting resistance to Fusarium infection: B73 (susceptible) and EA2024 (resistant), comparing the cell wall composition and structure of pith tissues between inoculated and non-inoculated plants.

Cell wall analysis of non-inoculated plants revealed variations between the inbreds in p-coumaric acid content, the degree of acetylation of arabinoxylans, and mixed-linked β-glucan levels, although no quantitative differences were detected in the major cell wall components. Detailed structural characterization of native polysaccharides obtained early through subcritical water extraction showed that EA2024 contained a pectin-enriched polysaccharide population. In contrast, susceptible line B73 exhibited a higher proportion of highly disubstituted xyloses in arabinoxylans extracted at later stages.

Infection had little effect on the overall native composition of the cell wall in either genotype but did influence the degree of arabinoxylan substitution. These findings contribute to a better understanding of maize cell wall structural characteristics associated with resistance to stalk rot disease and help clarify the role of this architecture in the progression of Fusarium infection.