Biocontrol Potential of Endophytic Plant-Growth-Promoting Bacteria against Phytopathogenic Viruses: Molecular Interaction with the Host Plant and Comparison with Chitosan

• Published in: International journal of molecular sciences Vol. 23; no. 13; p. 6990
• Main Authors: Shahzad, Gul-I-Rayna, Passera, Alessandro, Maldera, Giusva, Casati, Paola, Marcello, Iriti, Bianco, Piero Attilio
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 23-06-2022; MDPI
• Subjects: Agricultural production; Bacteria; Biological control; Chitosan; Chitosan - pharmacology; Controlled conditions; Cucumovirus - genetics; Cytomegalovirus Infections; defense-related genes; Endophytes; Flowers & plants; Genes; Genomes; Host plants; induced systemic resistance (ISR); Infections; Molecular interactions; Nicotiana - microbiology; Nicotiana benthamiana; Pathogenesis; Pathogens; Pest control; Pest resistance; Pesticides; Plant bacterial diseases; Plant diseases; Plant Diseases - microbiology; Potatoes; Potexvirus - genetics; Pseudomonas syringae; Ring spot; Viral infections; virus quantification; Viruses; induced systemic resistance (ISR); Nicotiana benthamiana; defense-related genes; virus quantification
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms23136990

Endophytic plant-growth-promoting bacteria (ePGPB) are interesting tools for pest management strategies. However, the molecular interactions underlying specific biocontrol effects, particularly against phytopathogenic viruses, remain unexplored. Herein, we investigated the antiviral effects and triggers of induced systemic resistance mediated by four ePGPB (
strain R8,
strain R16,
strain 255-7, and
strain 260-02) against four viruses (Cymbidium Ring Spot Virus-CymRSV; Cucumber Mosaic Virus-CMV; Potato Virus X-PVX; and Potato Virus Y-PVY) on
plants under controlled conditions and compared them with a chitosan-based resistance inducer product. Our studies indicated that ePGPB- and chitosan-treated plants presented well-defined biocontrol efficacy against CymRSV and CMV, unlike PVX and PVY. They exhibited significant reductions in symptom severity while promoting plant height compared to nontreated, virus-infected controls. However, these phenotypic traits showed no association with relative virus quantification. Moreover, the tested defense-related genes (
(
),
(
), and
(
)) implied the involvement of a salicylic-acid-related defense pathway triggered by
gene upregulation.