Shanghai-based researchers make discovery in plant defense against pathogens

A paper about a Shanghai research team's discovery of a pathway within plants was published on the website of the United States-based journal Cell on Monday.

According to the research, this pathway is used to transmit information of threats from pathogens, which would then elicit an immediate response from the plant.

Specifically, the pathway connects the plasma membrane and chloroplasts, which communicates with the nucleus to adjust the expression of genes in order to organize an appropriate defense response.

The team was made up of Chinese and foreign scientists at the Shanghai Center for Plant Stress Biology, Center for Excellence in Molecular Plant Sciences Affiliated with the Chinese Academy of Sciences.

The finding could pave a way for the development of new strategies to creating plant resistance to pathogen-caused diseases while maintain a high crop yield, scientists said.

In the paper, scientists stated that when the presence of a pathogen is detected, some plant proteins associated with the plasma membrane will move from the cell periphery to the inside of chloroplast to warn of the threat. Chloroplasts will then transfer the information to the nucleus and activate an appropriate defense to combat the potential invader.

Before their research, scientists understood that throughout evolution, plants have developed mechanisms to perceive the presence of a pathogen threat and mount defense responses to deter or eliminate the invading organism. But how the information travels into the cells remained unclear.

The scientists also found that this route used to transmit information inside the plant cell can be "hijacked" by pathogens.

Some proteins from plant viruses and pathogenic bacteria can mimic the behavior of the plant proteins, associating with the plasma membrane and moving to chloroplasts when the cell perceives an attack. Once in the chloroplasts, the pathogen proteins can impair the communication between the organelle and the nucleus, hence hampering the activation of defense responses, tilting the balance in favor of the invading microbe, said Rosa Lozano Duran, a leading researcher on the team.

"The finding that different kinds of pathogens have evolved similar strategies to take advantage of this plant pathway and utilize it to suppress plant defense in turn proves the core role that this pathway plays in transmitting the information of external threat from viruses, bacteria and fungi," said Duran from Spain, who has worked with the Shanghai-based center since 2015.

Duran said the team will look for collaborations to turn the research results into application.

"Pathogens cause dramatic losses in crop production worldwide, posing a threat to food security. Results obtained in this work suggested that 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 plant growth," she said.