City team probes plant defense mechanisms
Spanish botanist Rosa Lozano Duran, who is based in Shanghai, checks plant growth.
A Shanghai-based international research team has discovered how plants put up a fight against pathogens, offering new approaches to protect the natural world as well as new references to people’s anti-virus fight.
Plants live under different threats, including attacks by pathogens, which can sicken and even kill them, so they have evolved to develop a self-defense mechanism.
Plant proteins at the cell membrane can perceive the presence of potential attackers such as viruses, bacteria or fungus and trigger an alarm.
The alarm is then transmitted to the cell interior and reaches different cellular compartments, including chloroplasts which are unique in plants to drive the photosynthesis progress. When the nuclei receive the alarm, they will hit back by adjusting the expression of genes.
Although crucial for plant survival, how this information travels inside the cell was not fully understood. The recent research from the Center of Excellence for Molecular Plant Sciences (CEMPS) of the Chinese Academy of Sciences has given an answer.
The research, led by Spanish botanist Rosa Lozano Duran, has uncovered a pathway that connects the plasma membranes and chloroplasts.
Some plant proteins associated with the plasma membrane are messengers. When a pathogen is detected, they can move from the cell periphery to the inside of chloroplasts, therefore warning of danger.
Chloroplasts can then transfer this information to the nuclei in a process called retrograde signaling, which activates defense in order to combat the potential invader.
The research found that this route to transmit information inside the plant cell could be hijacked. Pathogen proteins can mimic the behavior of the messengers. They can move all the way to chloroplasts and impair communication with the nucleus, hence hampering activating the defense responses.
The study has been published in leading scientific journal Cell.
Unrelated effector proteins from viral and bacterial pathogens co-opt a plant pathway to dynamically translocate from plasma membrane to chloroplasts and suppress plant defense responses.
Pathogens cause dramatic losses in crop production, posing a threat to food security on a global scale.
According to Duran, the discovery of this novel pathway paves the way to the development of new strategies to engineer plant resistance to pathogen-caused diseases. It suggests it is possible to increase the strength of plant defense responses to attacking microbes without affecting productivity in the absence of pathogens, hence potentially improving plant health without compromising growth.
Han Bin, director of the center, said it also provides a reference to the fight against COVID-19.
Plants and animals have different cells, but the basic mechanisms against attacks are shared. That’s why the discovery was published in Cell, a magazine that focuses on a broad range of life sciences.
It can also help the center and Shanghai attract more overseas researchers, he added.
The center has 10 researchers from Canada, Japan, Greece and other countries. They enjoy great support in scientific research as well as assistance in housing and children’s education. In the research base on the Chenshan campus, CEMPS, “official languages” are Chinese and English.
“Basically, they can enjoy everything they had enjoyed in overseas countries,” Han said.
Duran, who has been working here since 2015, said: “It’s the best career move I’d ever made.”
She is a principal investigator at the center. Her research team, half Chinese and half foreigners, study how plant viruses cause diseases, with a special focus on the viral manipulation of cell functions.
After obtaining her PhD from the University of Malaga in Spain, she became a postdoctoral researcher at the Sainsbury Laboratory in Norwich in the UK before working in Shanghai.
