biology Not just for gourmands , truffles play essential roles in the health of ecosystems By

I t’s a cool November day near Bologna, Italy. We are strolling through the woods with truffle hunter Mirko Illice and his little dog, Clinto. Clinto runs back and forth among the oak trees sniffing the ground, pausing, then running again. Suddenly, he stops and begins to dig furiously with both paws. “Ah, he’s found an Italian white truffle,” Mirko explains. “He uses both paws only when he finds one of those.” Mirko gently pulls the excited dog from the spot and pushes through the soil with his fingers. He extracts a yellowish brown lump the size of a golf ball and sniffs it. “Benissimo, Clinto,” Mirko intones. Though not the finest example of the species, Tuber magnatum—which grows only in northern Italy, Serbia and Croatia—Clinto’s find will fetch a nice price of about $50 at the Saturday market. Throughout history, truffles have appeared on the menu and in folklore. The Pharaoh Khufu served them at his royal table. Bedouins, Kalahari Bushmen and Australian Aborigines have hunted them for countless generations in deserts. The Romans savored them and thought they were produced by thunder. Modern epicures prize truffles for their earthy aroma and flavor and are willing to pay steep prices at the market—recently more than $3,000 per kilogram for the Italian white variety. Yet despite humanity’s abiding interest in the fungi, much about their biology has remained veiled in mystery. Over the past two decades, however, genetic analyses and field observations have clarified the origins and functions of these organisms, revealing that they play key roles in many ecosystems. These findings are informing strategies for conserving some endangered species that rely on these denizens of the underworld.