The toxic and tough parts of plants can sometimes get more toxic or tough when induced. (Remember- inducible defenses are a cost-saving strategy for plants to “turn on” defenses when an attacker is present.) This paper by Dr. Don Cipollini provides a thinking-outside-the-box style of experiment by considering: what else* might turn on secondary metabolism? Turn on the fans!
That’s right, plant defenses can be turned on by wind!
Even further, plants from the fan treatments (wind simulation) were better protected against mites and fungi growth, which means the plant’s stress response to being blown around doubles as a protection against bugs** and pathogens! The defenses that increased in this case is called lignin, which is known for making cell walls tough (think stringy stuff in celery). Two enzymes involved in lignin accumulation also increased in windy treatments: peroxidase and cinnamyl alcohol-dehydrogenase (pro tip: usually if a biology word ends in -ase, it is probably an enzyme, which is a kind of protein (you know, the stuff our DNA tells our cells how to make).
So why does the way a plant responds to bugs and fungi after it sat in front of a fan matter? Wind is ubiquitous (=everywhere)! If wind patterns affect the way crops interact with bugs during a particularly windy year or how trees interact with diseases depending on how close they are to the other trees, it is important to incorporate wind into understanding pest resistance.
*Other environmental stimuli affect the phenylpropanoid pathway that produces the enzymes and phenolics measured in this study, but the novel piece here is that wind stress led to pest resistance.
**Again, technically “bugs” belong to the phylogenetic order Hemiptera, but the term has a mainstream alias which effectively describes insect herbivores.