Work

Aggressiveness of Subspecies and Sequence Types of Xylella fastidiosa and Plant Response in Nicotiana benthamiana

Year: 2026

Type: article

Abstract: The aggressiveness of 17 Xylella fastidiosa strains, representing different subspecies and sequence types (STs), was studied in the surrogated host Nicotiana benthamiana by analysis of the population levels and symptom dynamics, dose–effect relationships, and transcriptomic response of the plant. Colonization of all strains was observed after 7 days postinoculation (dpi), and the first symptoms appeared after 14 dpi. Differences in patterns of population dynamics and symptom development were observed between strains, and there was neither a relationship between population growth and symptom severity nor between strains of the same subspecies and STs. Strains IVIA 5387, DeDonno, CN28, and GP18 showed a typical S-shaped dose–effect curve, and the minimum infective dose in N. benthamiana was established at 300 CFU/plant for all strains. The plant response to infection by subsp. pauca ST53 strains DeDonno, CN28, and GP18 was studied in relation to the expression of defense genes. A strain-dependent modulation depending on time was observed, in which CN28 infection showed the highest gene overexpression (12 of 19 genes) and DeDonno the lowest (8 of 19 genes). At 4 dpi, all strains upregulated the genes PR1, PR1a, and ERF1 and downregulated the PDF1.2 gene, whereas at 30 dpi, most of the genes were downregulated, especially the pathogenesis-related genes, suggesting an immune evasion by the pathogen. Our findings are expected to provide valuable insights into the interaction between X. fastidiosa and its hosts, highlighting the importance of considering differences in aggressiveness among strains and in plant response. [Formula: see text] Copyright © 2026 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

Source: Phytopathology

DOI: 10.1094/phyto-11-25-0366-r

Authors: Aniol Buisac, Beatriz Gascón, Emilio Montesinos, Laura Montesinos

Institution: Universitat de Girona

Language: English

Topic: Phytoplasmas and Hemiptera pathogens

Subfield: Plant Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

SDG: Zero hunger

Open Access status: green

Funders: Ministerio de Ciencia, Innovación y Universidades, European Commission, HORIZON EUROPE Framework Programme