Jasmonic acid regulates plant development and orchestrates stress response during tough times

Jasmonic acid (JA) or methyl jasmonate (MeJA) are master regulators of plant development and stress response against pathogens and environmental fluctuations. Thus, JA is an important stress-associated phytohormone that can promote various defense interactions, regulate stomatal openness, synthesis of antimicrobial substances, or plant cell reprogramming. Numerous studies also demonstrated that plants thriving under environmental fluctuations stresses are linked to the JA response, revealing that JA application can alleviate the damage of abiotic stress by improving plant tolerance. Therefore, jasmonic acid and amino acid conjugate (JA-Ile) represent stress hormones that improve crop resilience under environmental fluctuations. In addition, JA modulates the plant growth and developmental stages by regulating the crosstalk between JA and the main plant hormone groups, balancing plant development and defense mechanism against pathogen attacks. The effects on various processes and plant structures, such as seed germination, primary root/root hair growth, fruit development, pollen maturation, senescence, and regeneration, have been documented for jasmonates. Therefore, we reviewed the functional influence of jasmonates, involving sensing and regulating their signaling under harsh conditions, which is becoming a top priority for agriculture. In addition, the crosstalks with other phytohormones, such as auxin, salicylic acid, ethylene, and the plant-pathogen interactions, are discussed.