Israeli scientists make biosensor for crop blight - study

Potatoes and tomatoes are among the most popular foods in the world, but they are susceptible to serious plant diseases that cause major crop losses.

Late blight disease is responsible for an estimated $6.5 billion in annual global crop damage.

In a new study just published in The Plant Journal published by the nonprofit Society for Experimental Biology, researchers at the Faculty of Agriculture, Food and Environment of the Hebrew University of Jerusalem (HU) used a new molecular sensor system capable of entering plant cells and identifying potential diseases.

Detecting plant infections to help global food security

With potatoes playing a crucial role in global food security, the researchers worked on developing a method to enable early detection of these plant infections. The study was led by doctoral student Matanel Hipsch under the supervision of Dr. Shilo Rosenwasser, a senior lecturer and assistant professor in the faculty, which is located in Rehovot.

“The development of advanced biotechnological tools for the early detection of plant diseases can lead to a future research breakthrough in understanding the pathogenicity process, thereby improving food security by minimizing damages to global agriculture,” Rosenwasser explained.

The new technique makes possible the early detection of various harmful diseases in the plant’s leaves with the help of a simple and harmless external scan. Using genetic engineering methods, the researchers produced new varieties of potatoes that create special proteins sent to different regions of the plant cells. As part of the process, the protein acts as a unique biological sensor that can be sent, for example, to the chloroplasts in the plant cells where photosynthesis occurs.

“In its early stages, it’s difficult to identify the disease because no external signs can be seen on the leaf,” Hipsch explained. “In our previous study, we saw that using molecular sensors within the biological systems of potatoes is particularly effective in identifying stress conditions even before plant damage has been caused.”

Using sensitive cameras that can pick up the signals sent from the sensor, they were able to get spatial information at the level of the entire plant. According to the researchers, the images produced by the cameras helped monitor the plant’s physiological state throughout the development of late blight in the potato.

The research findings revealed that the use of protein as a biological sensor was able to detect the diseased areas of the leaves even during the first invisible stages. These findings also led the researchers to collaborate with Dr. David Helman from HU’s soil and water sciences department to develop an AI-based algorithm capable of analyzing the fluorescent images and distinguishing between healthy leaves and infected ones.

“We have seen that plants infected with late blight cause the protein to emerge from the chloroplast and accumulate outside of it,” Hipsch explained. “This output caused a change in the fluorescent properties of the protein, which helped to identify the points of penetration of the pathogen into the leaf.”

One of their most fascinating findings suggested that the areas infected with late blight are characterized by higher photosynthetic activity compared to the rest of the leaf. The researchers explained that these results indicate how the pathogen maintains and even improves leaf productivity in the early stages of the disease to ‘disguise’ its development in the plant.

According to the team, the new method can be used for in-depth study of the mechanisms of resistance to late blight, as well as for scanning and detecting potential substances that will improve the resistance of plants.