Biologist Finds Way for New Approaches to Fight Plant Disease

Washington State University (WSU) biologist Michael Knoblauch has found what he calls a very strong support for an 86 year-old hypothesis about how nutrients move through plants. According to Knoblauch, 90 percent of the food we consume at one time went through a plant's phloem, where they are produced by photosynthesis, to roots and fruits. But scientists know so little about how this works.

Knoblauch has spent more than 20 years devising ways to look inside a living plant without disrupting the processes he was trying to measure and describe. He measured flow velocities with fluorescent dyes and radioactive isotopes, and developed a "picogauge" that could measure extremely sensitive phloem pressures. Using several microscopes, he measured the circumferences of not only plant stems, but the ciabatta-like holes of sieve plates that separate elongated cells in the phloem tissue. The cell geometries were particularly critical, as an order-of-magnitude change in the diameter of a tube or hole creates a four-order change in the volume delivered to the roots or fruits.

Knoblauch hopes that his work will result in new ways to protect plants, aside from building the evidence for a long-help hypothesis.

For more details, read the news release about the research in WSU News.