New Delhi: A MIT research found that rice seeds may sense the sound of the rain. Scientists discovered that the vibrations created by the sound of a raindrop falling can trigger the growth of a seed causing it to wake up and grow faster.
The study, published in Scientific Reports, offered new insights into how plants interact with the natural world.
For the experiment, the researchers first placed a thousand seeds in shallow water. Some were exposed to the vibrations of falling water, while others were kept in silent conditions. The results showed that seeds exposed to rain sounds germinated 30 to 40 per cent faster than those without sound exposure.
Seeds closer to the surface reacted more strongly as the sound vibrations were easier for them to detect.
Scientists believe this response connects to tiny structures inside plant cells called statoliths. These small particles, filled with dense starch, help plants sense gravity.
Normally, statoliths settle at the bottom of cells and guide roots downward and shoots upward. However, the sound vibrations from rain appear to shake these particles, sending signals that encourage seeds to start growing.
“Our study has shown that these same mechanisms seem to be providing plant seeds a means of perceiving submergence depths in the soil or water that are beneficial to their survival by sensing the sound of rain. It gives new meaning to the fourth Japanese microseason, entitled ‘Falling rain awakens the soil,’” said Nicholas Makris, a professor of mechanical engineering at MIT.
The idea might sound unusual, but plants have been shown to react to their surroundings in the past as well.
Some plants react to touch, light, smells, and even the buzzing of insects. Earlier studies have also shown that certain plants can respond to music or vibrations.
Certain flowers release pollen when they hear the buzzing of bees, while others increase their chemical defences when they detect the sound of insects eating nearby leaves.
MIT researchers used natural rain sounds for this experiment. Throughout the process, researchers recreated different levels of rainfall, from light showers to heavy storms.
They found that heavier rain produced stronger sound vibrations and led to faster germination. Light rain, on the other hand, had little effect.
They also compared the sounds made in the laboratory with real rain sounds recorded in wetlands, puddles, and rice fields. These comparisons confirmed that the lab conditions closely matched real life.
Interestingly, the researchers observed that the underwater sound of rain was found to be much stronger than expected. The pressure waves created underwater can be as intense as standing near a jet engine, though most of the sound exists outside the range of human hearing.
However, the study has opened new avenues for experiments.
Plants do not possess ears, brains, or nervous systems like animals. Still, they clearly react to environmental changes in complex ways.
Scientists are now debating whether this ability should be described as a form of “hearing” or simply a biological response to vibrations. While plants may not hear in the same way humans do, the research suggests they are far more aware of their surroundings than previously believed.
(Edited by Insha Jalil Waziri)