Use of two bacteria for biological control of bayoud disease caused by Fusarium oxysporum in date palm (Phoenix dactylifera L) seedlings

• Published in: Plant physiology and biochemistry 2012-06, Vol.55, p.7-15
• Main Authors: Dihazi, Abdelhi, Jaiti, Fatima, WafaTaktak, kilani-Feki, Olfa, Jaoua, Samir, Driouich, Azeddine, Baaziz, Mohamed, Daayf, Fouad, Serghini, Mohammed Amine
• Format: Article
• Language: English
• Subjects: Algeria; Antibiosis - physiology; Arecaceae - metabolism; Arecaceae - microbiology; Bacillus - physiology; Bacillus amyloliquefaciens; Bayoud; Bayoud disease; Biochemistry; Biochemistry, Molecular Biology; Biocontrol; Biological and medical sciences; Biological control; Biotechnology; Burkholderia cepacia; Burkholderia cepacia - physiology; Cell Behavior; Cellular Biology; Chemical Sciences; Chromatography, High Pressure Liquid; Coumaric Acids - metabolism; Date palm; Development Biology; Disease Resistance - physiology; Electrophoresis, Polyacrylamide Gel; Fundamental and applied biological sciences. Psychology; Fungal plant pathogens; Fusarium - physiology; Fusarium oxysporum; Fusarium oxysporum f. sp albedinis; Gametogenesis; Genomics; Host-Pathogen Interactions; Inoculation; Isomers; Life Sciences; Molecular biology; Molecular Networks; Morocco; Mycelia; Necrosis; Pathogens; Peroxidase; Peroxidase - metabolism; Peroxidases; phenolic compounds; Phenolics; Phoenix dactylifera; Phytopathology and phytopharmacy; Phytopathology. Animal pests. Plant and forest protection; Plant breeding; Plant Diseases - microbiology; Plant physiology and development; Plant Proteins - metabolism; Plantlets; Polymers; Seedlings; Seedlings - metabolism; Seedlings - microbiology; Shikimic Acid - metabolism; Spores, Fungal - physiology; Sporulation; Spreading; Subcellular Processes; Vegetal Biology
• ISSN: 0981-9428; 1873-2690
• DOI: 10.1016/j.plaphy.2012.03.003

The Bayoud, caused by Fusarium oxysporum f. sp. albedinis (Foa), is the most destructive disease of date palm (Phoenix dactylifera L) in Morocco and Algeria, with no effective control strategy yet available. In this work, two bacteria, Bacillus amyloliquefaciens strain Ag1 (Ag) and Burkholderia cepacia strain Cs5 (Cs), were examined for their potential to control this disease. Both bacterial strains inhibited both growth and sporulation of Foa. They released compounds into the culture medium, which resulted into cytological changes in Foa's mycelial structure. When Jihel-date palm plantlets, a susceptible cultivar, were induced with these bacteria, the size of the necrosis zone, which reflected the spreading of the pathogen, was reduced by more than 70%, as compared with uninduced controls. To further investigate the mechanisms of such disease reduction, phenolic compounds and peroxidase activity were assessed. One month after inoculation, date palm defense reactions against Foa were different depending on the bacterium used, B. cepacia led to higher accumulation of constitutive caffeoylshikimic acid isomers while B. amyloliquefaciens triggered the induction of new phenolic compounds identified as hydroxycinnamic acid derivatives. Peroxidase activity has also been stimulated significantly and varied with the bacterial strain used and with Foa inoculation. These results add to the promising field of investigation in controlling Bayoud disease. ► Bacillus amylolequefaciens and Burkholderia cepacia as biocontrol agent of date palm disease. ► Both bacterial strains inhibited both growth and sporulation of the pathogen. ► The two bacteria triggered differently the phenylpropanoid pathways in infected root. ► They enhanced peroxidase activity and induced new isozymes in infected root. ► These changes were associated with a decrease of disease severity.