Emission of floral volatiles can be regulated by phytohormone and defense signaling molecules. The production of jasmonic acid, a phytohormone, is a result of the pathway. One chemical mechanism related to DHN production is the presence of the phytohormone ABA. Lateral root cells then absorb the phytohormone through AUX1 permease. Witch's broom can be caused by cytokinin, a phytohormone, interfering with an auxin-regulated bud. The substance was characterized, was given the name "kinetin", and classified as a phytohormone. The function of "WUS" in the shoot apical meristem is linked to the phytohormone cytokinin. Another example of small molecule control of protein degradation is phytohormone auxin in plants.