WashU Expert: Richard Vierstra on new molecular ‘blueprint’ for how plants perceive light (Nature paper)

Plants rely on their ability to sense light for survival. Photoreceptors called phytochromes allow plants to detect different wavelengths of light; they are found in cells throughout plants, allowing plants to regulate their lifecycles and adjust to environmental conditions. But even though they were identified 70 years ago, it has remained unclear how phytochromes work.

Now scientists at Washington University in St. Louis and the Van Andel Institute have determined the molecular structure of one of these vital photoreceptors — for an isoform known as phytochrome B or PhyB — revealing a wholly different structure than previously known.

The findings, published March 30 in Nature, have many implications for agricultural and “green” bioengineering practices.

“Plant phytochromes are amazing molecular machines that perceive light and temperature through very specific conformational changes,” said Richard Vierstra, the George and Charmaine Mallinckrodt Professor of Biology in Arts & Sciences at Washington University and co-corresponding author of the study.

“The PhyB structure that we uncovered in this study tells us something that we never expected,” Vierstra said. “We learned that plant phytochromes are topologically complex, asymmetric and look nothing like their microbial relatives. And that they likely work in a wholly unexpected way.”

With the actual molecular structure of PhyB now in hand, scientists have a critical blueprint for guiding future efforts to create crop varieties more efficient in capturing light and better suited to a warming world.

Vierstra is an expert plant biologist who is known for elucidating the molecular mechanisms underpinning photoperception.

Read more about the Nature paper from Washington University in St. Louis or the Van Andel Institute.