Plants use a molecular alarm system to respond to insect pests . Plants use innate strategies to defend themselves from potential danger, such as predatory insects. In a new study from the Tokyo University of Science, experts have identified a molecular alarm system that alerts plants to the presence of insect pests.
Some plants can sense “herbivore-derived danger signals” (HDS), which are chemicals present in the oral secretions of insects. When this alarm is triggered, the plants launch a series of immune responses that ultimately help them develop resistance to the pests.
Researchers have been working for decades to understand the ability of plants to detect herbivore-derived danger signals on a molecular level.
In the current study, which was led by Professor Gen-ichiro Arimura, the experts set out to gain new insights into how plant HDS systems work.
“Scientists have been trying to understand the molecular mechanism of plant resistance for years, but the ‘sensors’ involved in plant recognition of insect pests are still not known. Thus, we wanted to get a detailed understanding of these mechanisms,” explained Professor Arimura.
The study was focused on membrane proteins called “receptor-like kinases” (RLKs), which are found in soybean leaves.
The research expanded upon previous studies in plants like Arabidopsis, tobacco, and cowpea. Among these plants, receptor-like kinases play a major role in HDS systems.
The researchers pinpointed genes for two RLKs – GmHAK1 and GmHAK2 – that showed a defense response specific to the oral secretions of insects. This is a major breakthrough because the role of these RLKs in soybean HDS systems had never been revealed before.
The experts also identified two similar mechanisms that are involved in danger response in Arabidopsis plants.
By uncovering an important cellular mechanism that triggers defense response in plants, the study represents a huge leap toward developing new strategies for pest control in crop plants. The manipulation of this innate system could ultimately lead to new agricultural products to help farmers prevent major crop losses.
“It has been challenging to find new pest control methods that are effective and do not harm the ecosystem in any way,” said Professor Arimura. “Our study offers a potential solution to this problem by uncovering the details of how certain plants develop resistance.”
The study is published in the journal Communications Biology.