Bacillus cereus strain S2 shows high nematicidal activity against Meloidogyne incognita by producing sphingosine

Abstract

Plant-parasitic nematodes cause serious crop losses worldwidely. This study intended to discover the antagonistic mechanism of Bacillus cereus strain S2 against Meloidogyne incognita. Treatment with B. cereus strain S2 resulted in a mortality of 77.89% to Caenorhabditis elegans (a model organism) and 90.96% to M. incognita. In pot experiment, control efficiency of B. cereus S2 culture or supernatants were 81.36% and 67.42% towards M. incognita, respectively. In field experiment, control efficiency was 58.97% towards M. incognita. Nematicidal substances were isolated from culture supernatant of B. cereus S2 by polarity gradient extraction, silica gel column chromatography and HPLC. Two nematicidal compounds were identified as C16 sphingosine and phytosphingosine by LC-MS. The median lethal concentration of sphingosine was determined as 0.64 μg/ml. Sphingosine could obviously inhibit reproduction of C. elegans, with an inhibition rate of 42.72% for 24 h. After treatment with sphingosine, ROS was induced in intestinal tract, and genital area disappeared in nematode. Furthermore, B. cereus S2 could induce systemic resistance in tomato, and enhance activity of defense-related enzymes for biocontrol of M. incognita. This study demonstrates the nematicidal activity of B. cereus and its product sphingosine, as well provides a possibility for biocontrol of M. incognita.

The Impact of Plant-Parasitic Nematodes on Agriculture and Methods of Control

“…have shown great promise in nematode management. B. cereus strain S2 treatment resulted in a mortality of 90.96% to M. incognita [147]. B. irmus YBf-10 exhibited nematicidal activity against M. incognita, which was clearly demonstrated by an inhibition of egg hatch and motility [148].…”

Biocontrol potential ofMicrobacterium maritypicumSneb159 againstHeterodera glycines

“…15 Currently, the utilization of biocontrol agents is considered a promising pest-control strategy. Numerous strains of microbial antagonists have been reported for their antagonism against PPN, [16][17][18] therefore, there is a justification for the continued discovery of biocontrol agents. One such biocontrol agent might be Microbacterium maritypicum, which was first isolated from sea water and marine mud.…”

High‐performance liquid chromatography/electrospray ionisation mass spectrometric characterisation of metabolites produced by Pseudovibrio sp. W64, a marine sponge derived bacterium isolated from Irish waters

“…Bacteria that are known to produce sphingolipids include Sphingomonas spp. and Myxobacterium spp., Bacteroides fragilis , Porphyromonas gingivalis , Burkholderia pseudomallei and Bacillus cereus strain S2 . Sphingoid bases have been reported to possess an array of biological activities including antiseptic, anti‐inflammatory and antimicrobial activity against Gram‐positive and –Gram‐negative bacteria …”

“…and Myxobacterium spp., Bacteroides fragilis, Porphyromonas gingivalis, Burkholderia pseudomallei and Bacillus cereus strain S2. 43,44 Sphingoid bases have been reported to possess an array of biological activities including antiseptic, anti-inflammatory 45 fragmentation pattern to aminodiols as discussed above and were tentatively identified as sphinganine (10), 48 C 20 -sphinganine (12) 49 and hydroxy C 22 -sphinganine (13), 50 as presented in Figure 2.…”