How volatile organic compounds strengthen plant defenses and provide sustainable pest control solutions

Volatile organic compounds (VOCs) are important airborne signals or odors that allow plants to communicate with other organisms and plants over short and long distances. An important aspect of this communication occurs when plants are damaged by herbivorous pests, causing the release of VOCs.

These compounds can be detected by neighboring plants and prompt them to mount stronger defenses against potential threats. This complex biochemical strategy allows plants to effectively protect themselves from various stresses.

This field of research has recently attracted great interest due to its potential applications in agriculture. In this vein, Professor Genichiro Arimura and his colleague Takuya Uemura from Tokyo University of Science in Japan set out to explore the molecular pathways behind this communication and its potential applications in sustainable agriculture.

Their review, published online October 11, 2024 in Trends in Plant Science, sheds light on these complex processes and their impact on agricultural advances. This study investigated how understanding plant-to-plant communication could lead to innovative strategies for crop protection and yield improvement, potentially revolutionizing sustainable agriculture.

“Although plants do not have sophisticated olfactory systems like animals, they are sensitive to structural similarities to compounds that plants and their ancestors encountered during beneficial or harmful interactions with various organisms.” Based on this, we can detect and react to a wide range of VOCs,” explains the professor. Mr. Arimura.

When attacked, plants emit different types of VOCs, including isoprene, terpenoids, and green leaf volatiles. These compounds have long been recognized for their role in cross-species signaling, attracting beneficial insects, or repelling herbivores.

In particular, monoterpenoids, which are abundant in mint plants, have been commercialized for their pest repellent, antibacterial, and ovicidal properties. This research has revealed that such plant-to-plant interactions can occur not only between closely related plants, but also between unrelated plants.

Once VOCs are released, they are absorbed through the stomata and diffused throughout the mesophyll cells of adjacent plants. Plant responses involve complex intracellular and intercellular signaling mechanisms. For example, calcium flux plays an important role in signal transduction cascades.

In plants that receive VOCs, hydrocarbons like β-caryophyllene can control gene expression by interacting with chromatin, the structure that controls access to DNA. This process, known as chromatin remodeling, triggers the activation of gene transcription, thereby preparing the plant for enhanced defense responses.

Currently, chemical pesticides are widely used to protect crops, but their harmful effects on the environment and the growing demand for higher food productivity have highlighted the need for safer alternatives. . The use of VOCs provides a sustainable solution that promotes both crop defense and productivity while reducing dependence on pesticides and other harmful chemicals.

Additionally, this new approach will reduce production costs and increase the value of agricultural products, as the majority of consumers prefer “pesticide-free crops” for their overall well-being.

“One promising approach is to incorporate companion plants that continuously emit beneficial VOCs, such as potted mint, candy mint, and peppermint.” “By developing stimulants, we may be able to further strengthen interactions between plants,” he argues. Mr. Arimura. They added that commercial products based on their new discoveries will soon be available in agriculture.

However, the practical application of VOC-based technologies in agriculture is limited by dose-dependent responses, inadequate distances between plants, and high concentrations of VOCs (allelochemicals) that can potentially inhibit the growth of neighboring plants. ) are facing several challenges.

This review paves the way for further research on VOCs in agriculture and encourages the scientific community to work with farmers and policy makers to harness the communication power of plants. By harnessing plants’ natural signaling mechanisms, we can develop sustainable agricultural practices that not only improve crop productivity but also promote environmental health.