Endophytic Insect-Parasitic Fungi Translocate Nitrogen Directly from Insects to Plants

Abstract

Plants That Eat Animals Apart from some spectacular exceptions, such as pitcher plants and Venus fly traps, most plants are thought to acquire nitrogen passively from microbial decomposition and the activities of nitrogen-fixing bacteria. Metarhizium species are common endophytes—fungi that live within plant tissues without causing disease. This genus is also found ubiquitously in soil, where they parasitize insects. In a series of microcosm experiments, Behie et al. (p. 1576 ) investigated whether these fungi could couple their endophytic life-styles with their parasitic modes and be a conduit by which plants could obtain nitrogen from animals. Radio-labeled moth larvae were added to the microcosms in which bean and grass plants were grown, and when the larvae were inoculated with fungi, it was only a matter of days before the nitrogen label was detected in the plants.