Synergistic effect of acetyl salicylic acid and DL-Beta-aminobutyric acid on biocontrol efficacy of Bacillus strains against tomato bacterial wilt

Abstract

This study was conducted to assess the biocontrol efficacy of Bacillus subtilis (strain 4812) and Bacillus methylotrophicus (strain H8) individually or in combination with two plant defense inducers including Acetyl salicylic acid (ASA) and DL-Beta-aminobutyric acid (BABA) against tomato wilt caused by Ralstonia solanacearum. The pathogen was significantly inhibited by all treatments in the greenhouse and in vitro tests. The treatments H8+ASA and 4812+H8 were found to be the most effective treatments in in vitro tests. Applied on tomato seeds and as soil drenching, the disease was most inhibited by H8 whereas 4812+H8+ASA was the least effective treatment. High activity of phenylalanine ammonia-lyase was observed in the plants treated with 4812+H8, H8+ASA and 4812+H8+ASA. The highest expression of peroxidase and polyphenoloxidase enzymes was found in the plants treated with H8, 4812+H8 and H8+ASA. The result of real time PCR showed that concentration of the pathogen in stem tissues was significantly reduced in all treated plants and H8+ASA was the most effective treatment. This study revealed that combined application of Bacillus strains can be considered as a more effective biocontrol agent against tomato bacterial wilt. Furthermore, the synergistic effect of plant defense inducers was variable to different Bacillus strains.

Efficacy assessment of various natural and organic antimicrobials against Escherichia coli O157:H7, Salmonella enteritidis and Listeria monocytogenes

“…El-Metwally et al (2015) emphasized that the treatment of seeds with (15 mM) of acetylsalicylic acid followed by H 2 O 2 (0.50 mM) can be used as a fungicide substitutes for controlling lupine root rot disease, improve growth and production. Additionally, Almoneafy et al declared the synergism of acetylsalicylic acid and DL-Beta-aminobutyric acid on biocontrol effectiveness against Bacillus strains causing tomato bacterial wilt (Almoneafy et al 2013). Our results contradict another study of benzoic acid against Escherichia coli, L. monocytogenes, and Salmonella enterica (Friedman et al 2003).…”

A consortium of rhizobacterial strains and biochemical growth elicitors improve cold and drought stress tolerance in rice (Oryza sativa L.)

“…solanacearum (Almoneafy et al . ). Although these findings support our current observations for the combination of SA and BABA, and their mixture with PGPR strains, strain H8 and D29 failed to have any impact on plant growth and stress tolerance in rice.…”

“…B. amyloliquefaciens strain D29 (JN411092) isolated, characterised and identified as potential plant growth‐promoting biocontrol agent, was used as positive control in these assays (Almoneafy et al . ).…”

Bacillus: A Biological Tool for Crop Improvement through Bio-Molecular Changes in Adverse Environments

“…In addition, pathogenic bacteria, including R. solanacearum and Xanthomonas oryzae , affect plant defense systems by decreasing phenylalanine ammonia-lyase (PAL; EC 4.3.1.24), POD, PPO, SOD, CAT, and lipoxygenase (LOX; EC 1.13.11) activities, but these defense enzyme activities are accelerated in diseased plants following the administration of Bacillus spp. (Chithrashree et al, 2011 ; Almoneafy et al, 2013 ; Kurabachew and Wydra, 2014 ; Table 2 ). PAL is involved in the biosynthesis of polyphenol compounds (lignin, flavonoids and phenylpropanoids) and triggering the plant resistance against environmental stimuli (Fritz et al, 1976 ; Tanaka et al, 1989 ).…”