by Monica Gagliano and Michael Marder
NOVEMBER 14, 2014
In 1999, the eminent journal Science published a special issue on plant biotechnology, which, according to Article 2 of the UN Convention on Biological Diversity, concerns the use of living organisms for the making of products with specific uses. Titled “The Plant Revolution” by Abelson and Hines, the Introduction to this special issue recites the glory of plant biotechnology, the many achievements and benefits of plant engineering for its capacity to deliver (questionably) healthier foods, and, most crucially, its contribution to global food security.
It is puzzling that as scientists and philosophers, we would glorify an approach that preaches sameness and uniformity, while we demand our undergraduate students to appreciate that Nature or Being thrives on variation and diversity. In the realm of biology, the existence of such variation amongst specimens and the selective mortality of individuals based on this variation are the fundamental principles of the Darwinian theory of natural selection. Shouldn’t we assume that the ecosystems themselves are capable of thriving successfully? We know very well that greater species diversity ensures ecosystem stability and, in turn, healthier ecosystems are more resilient to stress and can better withstand and recover from adverse conditions. We know equally well that modern industrialized agricultural practices focused on the monoculture of uniform crops lead to unstable agro-ecosystems, which become increasingly and rapidly susceptible to pathogen and weed infestations.
The plant biotechnology story, with its less than glorious revolution, seems to point to a dead-end. The good news is that this is not the only available narrative that science can offer. The other, parallel, story (and the other plant revolution) emerging from recent scientific research is, in fact, quite different in that it reminds us of how the plants themselves act by detecting shapes, colors, smells, sounds, and making accurate behavioral choices.
Here are only a very few examples. Plants tell stories of light, darkness and all shades in between, because it is through light that they get a sense of their neighborhood and it is by monitoring the light as well as the shadow cast by another plants that they are able to determine who is growing next to them and direct their own growth. In fact, plants are very sensitive to light as well as darkness and by using specialized pigments called phytochromes, they are able to detect specific light ratios reflected from or transmitted by their neighbors.
Plants also share stories of volatile affairs, of attractions and reactions based on an intricate chemical vocabulary that speaks to our very own noses and it is irresistible poetry for the olfactory receptors of many other animals. Sometimes, these are stories of fatal attractions when the smelly sweetness of honey-like substances on the leaf of plants like sundews becomes an inescapable and deadly ploy for an unaware insect. In turn, plants become the prey of herbivorous insects, for example, and at those times they can call for assistance by releasing volatile chemicals that attract the attention of predatory insects that will attack the attacking herbivores. By using a variety of herbivore-induced volatile organic compounds plants also warn their neighbors of the potentially imminent attack. They are able to respond to these cues produced by injured neighbors when they are not yet attacked or damaged themselves, hence allowing for pre-emptive defensive responses. We have now also learned that close relatives will be better able to detect and understand the cue than non-relatives.
And plants tell further stories of touchy feelings, like those expressed by the sensitive plant, Mimosa pudica that responds to mechanical disturbances like touch by folding its leaves and even ‘playing dead’ by drooping when disturbed as part of a defensive behavioural repertoire aimed at discouraging potential predators. For others like Dionaea muscipula (aka the Venus Fly trap), touch is not about avoiding predators but secures a nutritious meal with patience and perfect timing. This plants snaps together its modified leaves in fractions of a second, when two of the tiny hairs covering the inner surfaces of the leaves are stimulated within twenty seconds from each other by an unaware crawling insect. If the timing is not right, the trap is not triggered so that no energy is wasted for catching the unrewarding.
For numerous others, touch is about detecting mechanical stimulations and vibrations at a distance, as in the case of sounds. This is a story plants have quietly whispered in our ears for millennia but we have only recently attuned our technological ears to hear it. They generate structured acoustic emissions, which do travel in the soil and carry information to the rest of the community, even if we are still to learn what is being said. They are certainly listening to the soundscape around them, paying attention to sounds, which may be useful for reproductions or as warning signals for defense. And, no matter the senses involved, plants remember what they have learned through their experiences and, like all animals, they use the learning process to adapt and flourish into the future.
Together with other numerous stories that plants tell us about themselves, these are certainly not the signs of insensitive object-like organisms. Appropriately, a theory is supported when its predictions are confirmed by our observations of reality and it is challenged, rectified and even rejected when its predictions prove to be false.
So the question that emerges is this: How can we ethically justify, promote, and financially subsidize the use of plants in the context of plant biotechnology and bioengineering, when the premises of this scientific endeavor are rooted in the erroneous view of plants as insensitive objectified organisms? The development of plant bioengineering, particularly genetically modified (GM) plant research, is an emotionally charged issue in our societies. Yet, the growing scientific evidence demonstrating that plants are highly sensitive organisms, rather than mere objects, can offer a detached and unequivocally clear resolution to a much-heated issue. It is based on the state of this current knowledge that the scientific method prompts us to rectify our approach by de-objectifying plants and hence, no longer granting scientific legitimacy to GM research on plants.
At a time when our societies rely on scientific prowess to provide answers to the current socio-environmental crisis, applying the scientific method with the uttermost integrity is a must. In de-objectifying plants, we not only provide a thicker philosophical account of what (or who) they are, but, most importantly, we take responsibility for how we relate to them as living beings in their own right. Failing to integrate new evidence and correct, or, when appropriate, reject old theories is what defines pseudoscience and sloppy philosophizing. To live up to the tasks of philosophy and science, we need urgently to reconsider the way we view and treat plants.