Thanks to certain epigenetic mechanisms (changes in the expression of genes, triggered by the environment) some plants seem to “remember” certain experiences that affect their survival . For example, three years ago, scientists at the University of Nebraska-Lincoln (USA) found that Arabidopsis thaliana responded by consuming water more wisely when subjected to periods of drought. The stressful experience was stored and over-activated two genes involved in its less generous management of water resources .
However, this appears to be more the exception than the rule, according to a study led by Peter Crisp of the National University of Canberra (Australia). Although remembering misfortunes seems to be helpful in anticipating their recurrence, the costs often outweigh the benefits. As Steven Eichten , a member of the Crisp team, explained: “the organism spends too much energy transcribing genes that are then not needed at a specific time .”
In addition, they can also bequeath their traumatic memories to their offspring, as happens to the Polygonum hydropiper species, which in periods of scarcity and stress produces smaller seeds that are less well prepared to thrive under normal conditions. What the experts have discovered is that, in general, the mechanisms to record the negative experience – which, biologically, involves producing a protein to alter its DNA – is not usually activated by the disorders that this epigenetic change brings, both to the plant and their offspring. In other words, being forgetful pays off.
