Final answer:
Jasmonic acid in plants is seen in response to pathogen attack, where it plays a crucial role in plant defense by mediating the synthesis of toxic compounds and volatile compounds to deter predators and attract aid.
Step-by-step explanation:
We can see jasmonic acid in plants in response to pathogen attack. As an integral component of plant immune response, jasmonic acid's levels increase significantly during instances of tissue damage caused by biotic stress factors such as herbivores and pathogens. The research comparing mutant plants deficient in jasmonic acid production (Ja-) with normal plants (Ja+) illustrates the crucial role jasmonic acid plays in plant defenses. For instance, when plants are attacked by pathogens like mold or insects such as moths, jasmonic acid mediates defense responses that include the synthesis of both toxic compounds to deter predators and volatile compounds to attract beneficial organisms that can aid in the plant's defense.
When looking at defense mechanisms, the closure of stomata can be cited as a plant's front-line defense against bacterial infection, mediated by the phytohormone abscisic acid (ABA). This reflex helps limit pathogen entry and water loss. Additionally, the systemic defense reactions triggered by jasmonic acid can lead to the activation of abscission in severely damaged tissue, thereby possibly averting further spread of pathogens or damage.