Hark! Are the plants chatting with each other?

NEW DELHI: Plants may be able to 'talk' to each other say researchers from the University of Western Australia after carrying out experiments in which two types of plants were completely separated from each other and yet one appeared to influence the other.

Basil, known and revered in India as 'tulsi', is well known to have a beneficial effect on neighboring plants. This is because it gives out some organic volatile substances that inhibit the growth of some weeds. Its roots retain moisture longer and so help the neighboring plants. Earlier research had established that like basil, many plants 'communicate' to other plants by chemicals, touch or shade giving.

But in this latest research by Monica Gagliano and Michael Renton, published online in the scientific journal BMC Ecology, it was shown that basil plants could influence chili plants in a positive way even after they were completely separated from each other by a vacuum barrier.

The researchers said that since chemical, touch or light communication was ruled out, the possibility of 'acoustic' signals, that is, sound was strongly suggested. They suggested that 'nanomechanical oscillations of various components in the cytoskeleton can produce a spectrum of vibrations' communicating to other plants necessary information.

In the experiments, chili seeds were planted surrounding a basil plant which was enclosed in a double walled box with vacuum between the two walls. The whole set of plants was further enclosed in a similar double walled vacuumed box to block any outside interference.

It was discovered that chili seeds planted next to the basil plant germinated faster than those which did not have the good neighbor. This happened irrespective of whether the basil plant was masked (kept in the box) or open (no box).

According to the researchers this shows that the other methods of communication (light, touch or chemicals) play an important role but are not the exclusive means with which plants communicate. That is why they theorise that tiny sound waves might be doing the same job.

Why do plants communicate? The researchers suggest that this is an adaptive mechanism by which plants prepare to respond to the competitive environment right from the point of seeds germinating. If they have competing species, they may be triggered to opt for faster growth, and so on.