Informace o publikaci
The change in virulence of nematode Heterorhabditis bacteriophora during storage
| Autoři | |
|---|---|
| Rok publikování | 2019 |
| Druh | Další prezentace na konferencích |
| Fakulta / Pracoviště MU | |
| Citace | |
| Popis | Entomopathogenic nematodes are parasites of insect. Their infective stage – infective juvenile (IJ) – lives freely in the soil and seeks for insect host. After penetration into the host via natural openings or via cuticle, the nematodes release their symbiotic bacteria which they carry in their gut. Together they are capable to kill the host within two days for which they are used in agriculture as pest biocontrol. As the virulence of this nematobacterial complex is important for its effectivity, this study is focused on the change of virulence during IJs storage.It is known that nematodes produce and secrete mix of proteins containing proteases and substances with different biological functions. These excreted/secreted products (ESP) help nematodes and their bacteria to overcome insect immune system and enable nematodes to reproduce and develop. However, there is lots of unknown as the mix of proteins changes according to various factors, e.g. nematodes species, host species, phase of infection or age of infective juveniles.In this work, nematode Heterorhabditis bacteriophora strain Az148 with its symbiotic bacteria Photorhabdus luminescens was studied. For virulence test we used larvae of greater wax moth Galleria mellonella infected with H. bacteriophora and recorded their mortality after 48 hours. We compared newly emerged IJs with those stored for 7, 14, 21, 28 and 35 days. We observed that the mortality of G. mellonella larvae was low when newly emerged IJs and IJs stored for 7 days were used and significantly increased when we used IJs stored for 14 and more days. Furthermore, we tested correlation of the proteolytic activity of isolated ESP with virulence development. This knowledge can help to effectively use Heterorhabditis bacteriophora in fight against the insect pest. Also, the work on ESPs can bring deeper understanding of the process of infection and overcoming insect immunity. |