MEATY snacks: they鈥檙e not just for Venus flytraps. Almost any plant can be a carnivore with the help of fungi that kill insects and carry the nutrients into the plant鈥檚 roots.
Most plants cannot take nitrogen directly out of the air or soil, so they rely on fungi and bacteria to capture it from, for instance, decaying organic matter in the soil. Among the most ubiquitous of these fungi are Metarhizium. The fungi release enzymes to eat through an insect鈥檚 shell, then slowly take over the host and kill it from the inside.
A team led by Michael Bidochka of Brock University in St Catharines, Ontario, Canada, wondered whether the insect-killing and plant-feeding were linked. They injected labelled nitrogen into wax moth larvae (Galleria mellonella) and infected them with fungi. The team then buried the larvae in the soil with either beans or switchgrass plants. A screen with pores too small for plant roots to penetrate but large enough for the fungi to traverse separated the insects and the roots.
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After 14 days, the researchers found their labelled nitrogen in the plants鈥� tissues (Science, ).
鈥淚t completes the circle,鈥� says Raymond St Leger, an entomologist at the University of Maryland in College Park. Insects eat plants, but plants get their revenge eventually.