Plant development, stress responses, and secondary metabolism under ethylene regulation

Ethylene plays many important roles under plant development, stress responses and secondary metabolism. Nevertheless, a proper review of the modulation and regulation of ethylene in plant development, stress responses, and secondary metabolism is limited. Therefore, this review is done to provide appropriate documentation on those related topics. This review was limited to the searching of keywords of the followings ("ethylene", "plant secondary metabolite", "plant development and growth", "ethylene modulates both growth and senescence", and "regulation and modulation of ethylene") and data from 2016 to 2021 only. Hence, this review might not conclude all relevant studies. The modulation of ethylene was divided into two which are plant development and plant protection whereby ethylene mostly protects the plants during growth and stress conditions. Meanwhile, the regulation of ethylene on the production of plant secondary metabolites like phenolic compounds, alkaloids, glucosinolates, and terpenoids showed that ethylene was able to promote or inhibit the contents of secondary metabolites in plants. In summary, ethylene was shown to play a significant function in modifying and controlling plant development and protection under stress conditions including thermal and water stress which are very important in plant response under climate change and drought situations. Despite the significance of ethylene in plants that were described, published studies on ethylene regulation in secondary metabolism were still limited hence further studies in this area can be intensified.