A groundbreaking study led by a team of researchers from the University of Toronto Scarborough has uncovered a surprising function of the waxy protective barrier surrounding plants. Published in the journal Proceedings of the National Academy of Science, the research suggests that this protective layer may play a crucial role in sending chemical signals to other plants and insects, opening new possibilities for the development of more resilient crops.
The study focused on cuticular waxes, a thin layer that plants deposit on their surface to protect against water loss. According to Eliana Gonzales-Vigil, an assistant professor in the department of biology and the study’s lead researcher, these waxes act as a physical defense, preventing plants from drying out rapidly. They are essential for shielding plants against various environmental stressors, including ultraviolet radiation, fungus, bacteria, and temperature extremes.
Contrary to previous beliefs that these waxes were stable and unreactive barriers, the research discovered that some waxes break down when exposed to air and light, releasing other compounds in the process. The analysis focused on a species of poplar tree (cottonwood), revealing that unsaturated waxes, known as alkenes, degrade to produce a well-known aldehyde signaling compound and insect pheromone called nonanal.
Although the biochemistry involved is complex, the key finding is that smaller, interesting compounds can be released from the larger waxes found in plants. Gonzales-Vigil emphasizes the potential application of this process to engineer desirable traits in plants, enhancing their resilience to drought or insect damage.
The role of aldehydes in both plants and animals is significant, serving as signaling molecules that influence growth, development, and reproduction. In plants, aldehydes are present in pheromones attracting insects and facilitating plant-to-plant communication, especially in response to stressors like drought.
Jeff Chen, a recent master’s graduate in cell and systems biology at U of T Scarborough, made a noteworthy contribution to the study. Chen discovered that waxes can break down into aldehydes over time, a surprising revelation given the expectation of stability throughout a plant’s lifetime.
The study’s findings extend beyond the specific species studied, with implications for improving the resilience of various crops, including food crops. The potential to use plant waxes to create slow-release pheromones for insect attraction or repulsion opens exciting opportunities in agriculture. Additionally, the discovery could pave the way for cost-effective and natural alternatives to synthetic processes currently employed for such purposes.