Each creature on this Earth communicates with each other through some sounds or signals. Their frequency can be too high or too low for us to detect or determine them, but they do produce sounds. Similarly, even trees and plants fizz with the sound of tiny air bubbles bursting in their plumbing. The researchers have found evidences of communication between plants and insects or birds. The insects and plants can hear each other's sounds and signals. For example, the bees buzz at just the correct frequency to release pollen from tomatoes and other flowering plants and bark beetles may pick up the air bubble pops inside a plant which is a hint of trees experiencing the drought stress.

The sound and signals are so much fundamental to our life that some of the scientists now think there's a kernel of truth to folklore that holds humans can commune with plants. And the plants may use sound to communicate with one another just like bacteria who signal each other with vibration.

Early in 1960s, the scientists first recognized that listening to leaves revealed the health of plants. We all are aware about the process of transpiration, where leaves open their pores to capture carbon dioxide, and lose huge amounts of water. To replace this moisture, roots suck water from the ground, sending it skyward through a series of tubes called the xylem. Pit membranes, essentially two-way valves, connect each of the thousands of tiny tubes. The drier the soil, the more tension builds up in the xylem, until the pop, an air bubble is pulled in through the membrane. In some cases, these embolisms of plants are deadly, as with human blood vessels because the gas bubbles block the flow of water. The more air in the tubes, the harder it is for the plants to pull in water. But researchers who pondering upon the plant hydraulics are discovering that certain species, like pine trees and Douglas firs, etc, can repair the damage on a daily or even an hourly basis. These cycles of embolism formation and refilling are happening every day. This is just like a revolution in the field of plant biology. The movement of water in the plant is a passive process driven by the procedure of evaporation from the leaves. Now, this is considered to be a dynamic process.

The technology of hearing plant bubbles explode is quite simple and easy. Acoustic sensors (AS) which are designed to detect cracks in the bridges and buildings, catches the ultrasonic waves. A piezoelectric (PE) device which is similar to the electric guitar goes through an amplifier to an oscilloscope that measures the waveform of each wave. The device acoustic sensor is quite expensive, so the researchers are trying to build a low-cost version of this device. The National Science Foundation and the U.S. Department of Agriculture are providing funds for this piece of work.

The phenomenon of plant hydraulics can solve the puzzle and estimate the lifetime of plant species according to the change in climate. This will tell us about how our future forests will look like in 50 years. This will definitely aid many geologists and weather forecasters in their field of research. The two geologists from Arizona are also trying to build a low-cost acoustic detector.

This fascinating piece of work can actually solve many environmental problems, like drying, heat stress, cold stress, etc. Now, it has become easier to listen to the plants and understand their problem. This will help in distinguishing one problem from the other. The signals produced by the plants and trees can differentiate the two different conditions as each frequency of sound notifies different situations. As for example, we can find difference in the signals produced by the plant for the condition of cold stress and dehydration. The scientists are trying their best to differentiate these two different signals. This new invention can bring a huge change in the area of plant biotechnology and make the research on stress conditions easier.

About Author / Additional Info:
Geetanjali Murari
Email Id: geetanjali1232@gmail.com