Studying what makes plants sick gives insight into animal and human health

Sheng-Yang He is a Howard Hughes Medical Institute Investigator and an MSU University Distinguished Professor

MSU University Distinguished Professor Sheng-Yang He.

Sheng-Yang He’s recent work takes plant research from the lab to mimic field conditions in order to understand how disease susceptibility works in the real world. His research will help improve crop productivity and resilience and also shine a light on the mechanics of infectious diseases in animals and humans.

A Howard Hughes Medical Institute Investigator and an MSU University Distinguished Professor in Plant BiologyPlant, Soil & Microbial Sciences and Microbiology & Molecular Genetics, He started his lab more than two decades ago with a focus on how plant disease occurs at the molecular level. His ultimate goal has been to find weak links in plants, modify those to make the plant more resistant and then transfer the new traits to crops.

In the last few years, He has shifted emphasis to studying how environmental conditions, like humidity, influence disease outbreak. More recently, his work examines how global warming affects plant disease.

Additionally, He is breaking new ground in understanding the importance of a balanced plant microbiome – microorganisms that are tightly associated with a certain plant species or genotype – and the role it plays in regulating plant health.

“Without a balanced microbiome, the plant becomes sick in a way that is very reminiscent of diseases such as inflammatory bowel disease (IBD) in humans,” He said. “IBD is caused by mutations in immune response genes in the human body coupled with something physiological and environmental conditions, like food. In plants, if you affect the immunity response, plus some other environmental factors, such as high humidity, plants will have spontaneous tissue damage, even without pathogen infection, resembling [an imbalance of the gut microbiome] in humans. 

“This discovery suggests a very interesting parallel between human health and plant health that even without pathogen infection, a balanced microbiome is really important for health.”

The processes He studies in plants may be, one day, translated to the development of therapeutics that could treat imbalances in plants and, perhaps, also IBD and associated diseases in humans, he said.

“Conceptually, the basic fundamentals for the way a bacterial pathogen affects plants is very similar to the way a human pathogen, like salmonella, attacks us. These pathogens produce a lot of toxic proteins and they inject these proteins into either a plant cell or a human cell,” He said. “Even though the specific toxic proteins that are injected into plant cells or human cells are different, but they ultimately do the same thing. Many of these toxic proteins shut down the immune response in either the plant cell or the human cell.”

The discovery of how bacteria interact with plants has broad implications in understanding not only plant diseases, but also animal and human disease mechanisms. That has been one of He’s most satisfying feelings as a plant scientist. The National Institutes of Health and Howard Hughes Medical Institute, among others, have funded He’s plant research presumably in part due to the benefits of better understanding human disease responses. 

“Plant research is relatively easy to do and plants are very affordable model organisms to understand the basic principles of the microbiome, the pathogen, the host and how they interact with each other to maintain the host’s health,” he said. “I hope that our study contributes to the emerging realization that there are many fundamental processes in plant, animal and human health that are commonly affected by microbes.”

This article was published in Futures, a magazine produced twice per year by Michigan State University AgBioResearch. To view past issues of Futures, visit www.futuresmagazine.msu.edu. For more information, email Holly Whetstone, editor, at whetst11@msu.edu or call 517-355-0123.

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