Answer

       Chemical Ecology in Plant

1. How have humans taken advantage of the chemicals that plants produce for their own defenses?

            Due to the lack of immune system comparable to that in animals, plants develop a chemical mechanism to detect and defend themselves from other organisms. However, humans are taking advantage of these toxic chemicals. For protection, plants produce Terpenoids which is a bioactive natural compound with the ability to form essential oils that have a toxic and repellant effect on insects (Sánchez & Contreras, 2017). An example of such oils is the limonene in the citrus plant.  Humans are using these essential oils made from terpenoids to make fragrances, perfumes and food additives due to their variety of aromas. The chemical is also used for traditional medication such as aromatherapy.

            Plants also produce Salicylic acid for their defense. This chemical is an essential monitoring molecule conveys pathogen-triggered signals observed by various immune receptors to initiate downstream defense responses in a plant (Sánchez & Contreras, 2017). Salicylic acid accumulation enables plants to induce defense responses. Humans are using Salicylic acid as a medicine to treat dandruff, psoriasis, warts, calluses, ringworm, acne and ichthyosis because of its ability to remove the outer layer of the skin.  

2. What would happen if these toxic compounds were selected against in breeding plants?

            If the toxic defense compounds are selected against in breeding plants the process may not bear the desired result because the plants will lack the ability to detect and protect themselves from the surrounding stress necessary to cause extensive damages.    

3. Which defense do you find to be the most interesting and why?

            I find the chemical defense to be the most interesting. The chemical defense mechanism is interesting because plants produce toxic defensive metabolites to protect them from the surrounding stress but these chemicals do not deter the normal vegetative plant development and growth (Sánchez & Contreras, 2017). The compounds can also be stored in inactive forms and only be induced when an attack is observed.