A case of Pyrola plantlets with picky palates leads to new insights on mycoheterotrophic seedlings and the fungi that feed them

Plants have evolved many strategies to ensure seed germination and seedling survival. One of the most intriguing strategies utilized by a subset of dust-seed producing plants is initial mycoheterotrophy. Rather than relying solely on a seed’s own reserves, initially mycoheterotrophic plants employ fungi to provide much or all of the carbohydrates necessary to feed a developing seedling (Leake, 1994). This strategy has allowed plants to circumvent the tradeoff of producing numerous small seeds capable of long distance dispersal that consequently possess limited carbon (C) reserves to feed a growing seedling. However, initial mycoheterotrophy has its own limitations. For example, often it involves very specific pairings among plants and particular lineages of fungi (Leake et al., 2004). Thus, a plant dependent on specific fungi for germination or seedling development must first come into physical contact with a compatible fungal partner. The paper in this issue of New Phytologist by Hashimoto et al. (pp. 620–630) is the first to reveal the identity of the fungi responsible for the mycoheterotrophic germination and seedling development of Pyrola asarifolia (tribe Pyroleae, family Ericaceae) a fairly widespread evergreen herb found in Japan, North America, and Europe, whose early fungal associates have remained a mystery until now.