In the early 1920s, farmers in New Jersey noticed their potatoes were shriveling, their leaves becoming deformed. The plants were sick with an illness that came to be known as potato spindle tuber disease. But it took almost five decades for someone to find the cause.

In 1971, Theodor O. Diener, a plant pathologist at the Department of Agriculture, discovered that the culprit is an inconceivably tiny pathogen — one-80th the size of a virus. Dr. Diener called it a viroid.

Since Dr. Diener’s initial discovery, scientists have identified nearly three dozen species of viroids that attack crops from tomatoes to coconuts, as well as flowers such as dahlias and chrysanthemums.

Continue reading “A Tiny Emissary From the Ancient Past” →

The whitebark pine grows in the high, cold reaches of the Rocky and Sierra Mountains, and some trees, wind-bent and tenacious, manage to thrive for more than a thousand years.

Despite its hardiness, the species may not survive much longer.

A lethal fungus is decimating the pines, as are voracious mountain pine beetles. Making matters worse, forest managers have suppressed the fires that are required to stimulate whitebark pine seedlings.

Continue reading “For Trees Under Threat, Flight May Be Best Response” →

“Microorganisms are the best chemists on the planet,” declared Michael A. Fischbach, a chemist himself at the University of California, San Francisco.

For evidence, Dr. Fischbach points to the many lifesaving drugs that microorganisms produce. In 1928, for example, Alexander Fleming discovered that mold wafting into his lab produced a bacteria-killing chemical that he dubbed penicillin.

Later generations of scientists found drugmaking microorganisms in more exotic locales.

Continue reading “Mining for Antibiotics, Right Under Our Noses” →