Multitrofične interakcije med rastlinami, talnimi škodljivimi žuželkami ter entomopatogenimi ogorčicami / Multitrophic interaction between plants, underground pests and entomopathogenic nematodes

Abstract

IZVLEČEK

V kmetijskih ekosistemih lahko talni škodljivci povzročijo veliko gospodarsko škodo. Za njihovo zatiranje se največkrat uporabi kemična fitofarmacevtska sredstva, ki pa imajo lahko tudi negativne vplive na okolje. Raziskovalci zato preučujejo druge možnosti zatiranja tako nadzemskih kot tudi talnih škodljivih organizmov v kmetijstvu. Gibanje organizmov je povezano z zaznavanjem kemičnih dražljajev iz okolja. Študije so v zadnjih letih pokazale, da se proti kemičnim dražljajem lahko gibajo tudi naravni sovražniki škodljivcev (entomopatogene ogorčice). Govorimo o t.i. neposredni obrambi rastlin pred škodljivimi organizmi. Rastlina, ki jo je napadel herbivor, začne v okolico sproščati kemične signale, ki na naravne sovražnike povzročitelja delujejo privabilno. Doslej je bilo identificiranih le nekaj ključnih spojin, ki so odgovorne za posredovanje v tako imenovanih multitrofičnih interakcijah in le nekaj genov ter biokemičnih poti, ki so odgovorne za proizvodnjo hlapljivih organskih snovi (HOS). Mnoge spojine ostajajo še vedno neznane, toda identifikacija le-teh ima velik potencial za uporabo pri varstvu rastlin. Napredki v razumevanju rastlinskih emisij in njihove vloge pri signaliziranju predstavljajo enega izmed novih načinov manipulacije rastlinskih eksudatov, s katerimi bi izboljšali naravne obrambne lastnosti rastlin.

Ključne besede: entomopatogene ogorčice, talni škodljivci, HOS, neposredna rastlinska obramba

ABSTRACT

In agricultural ecosystems, soil pests can cause great economic damage. Pesticides are often used for their control, but they may also have negative effects on the environment. Researchers are therefore exploring other options for suppressing both above-ground and soil-dwelling organisms in agriculture. The movement of organisms is associated with the detection of chemical stimuli from the environment. Studies have shown in recent years that natural enemies (entomopathogenic nematodes) of pests can also move against chemical stimuli. The term is known as an indirect plant defense. The plant that has been attacked by the herbivor starts to release chemical signals to the environment, which act on the natural enemies of the pests. To date, only a few key compounds have been identified that are responsible for mediation in so-called multitrophic interactions and only a few genes and biochemical pathways that are responsible for the production of volatile organic compounds (VOCs). Many compounds remain unknown, but their identification has great potential for use in plant protection. Progress in understanding plant emissions and their role in signaling is one of the new ways to manipulate plant exudates to improve the natural defenses of plants.

Key words: entomopathogenic nematodes, soil-dwelling pests, VOCs, indirect plant defense