Endophytic bacterium,Bacillus amyloliquefaciens, enhances ornamental hosta resistance to diseases and insect pests

Abstract

A total of 84 bacterial endophytes were isolated from seeds of 6 cultivars of ornamental hostas, and they were identified to 5 species based on morphological characteristics and 16S rDNA sequence analysis. Among them, the strain 'Blu-v2', which was isolated from the seeds of cultivar 'Blue Umbrella' and identified to be Bacillus amyloliquefaciens, showed highest antifungal activity and capacity to deter feeding by Fall armyworms (Spodoptera fruigiperda). Lipopeptides in cultures of Blu-v2 were determined using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) and its antifungal activities were verified. However, the lipopeptide preparation did not show toxicity to larvae of Fall armyworms. In a greenhouse experiment, Blu-v2 was inoculated into small plantlets of hosta (cultivar 'Rainforest Sunrise'). The leaves of plants with bacteria (endophyte-infected = E+) and without bacteria (endophyte-free = E−) were used in seven-day feeding experiments employing fourth-instar larvae of Fall armyworms. We found that there was a significant decrease in the weights of larvae fed with E+ compared to E− plants; and the mortality rate of larvae fed with E− leaves was lower (3.33%) compared to that of larvae fed with E+ leaves (30%). Based on our studies, we suggest that endophytic B. amyloliquefaciens strain Blu-v2 has potential value as a biocontrol agent to reduce damage from fungal diseases and insect pests of hosta cultivars.

Endophytic Strain Bacillus subtilis 26DCryChS Producing Cry1Ia Toxin from Bacillus thuringiensis Promotes Multifaceted Potato Defense against Phytophthora infestans (Mont.) de Bary and Pest Leptinotarsa decemlineata Say

“…Sensitivity of the majority of biopesticides based on commercial strains to temperature regime, atmospheric precipitations, and other conditions put bounds on their extensive use. Involvement of endophytic strains in farming techniques can solve the problem [ 7 , 18 ].…”

“…Thus, this suggests the necessity for the development of environmentally safe biocontrol agents that reveal combined biocidal impact on abundant pathogens and pests, and which will be capable to give rise to systemic resistance in host plants. Consequently, a beneficial and heterogeneous group of plant growth-promoting bacteria (PGPB), inhabiting the rhyzosphere, phyllosphere, and internal tissues of plants, is of great interest [ 7 , 8 , 9 ].…”

Synthesis and characterization of silver nanoparticles using Bacillus amyloliquefaciens and Bacillus subtilis to control filarial vector Culex pipiens pallens and its antimicrobial activity

“…Bacillus amyloliquefaciens is one of the most common bacterial endophytes, which infected many plants and it has gained considerable attention due to its beneficial effect of improving plant disease resistance, where, crude lipopeptides from cultures of B. amyloliquefaciens showed antagonistic activity against three kinds of pathogen. However, the feeding larvae test of fall armyworms (Spodoptera fruigiperda) did not show a significant difference in weight gains between larvae fed with leaves dipped in crude lipopeptides and with control leaves (Chen et al 2013;Li et al 2015). Biocontrol-active isolates of B. amyloliquefaciens and B. subtilis produce various antimicrobial CLP, including surfactin, iturin A, and fengycin.…”

The Hsp90 Inhibitor, Monorden, Is a Promising Lead Compound for the Development of Novel Fungicides

“…Endophytic bacteria and fungi are symbiotic microorganisms living inside healthy plant tissues without causing any disease symptoms. Some beneficial endophytes stimulate plant growth by producing plant hormones such as indole-3-acetic acid (Santoyo et al, 2016;Hassan, 2017), improve the tolerance to abiotic stresses (Pandey et al, 2018), or promote the plant immunity against microbial pathogens, insects, and herbivores (Azevedo et al, 2000;Ryan et al, 2008;Li et al, 2015;Bamisile et al, 2018).…”