The confluence of TOR signalling and plant growth regulators in development and stress responses

Target of Rapamycin (TOR) is an evolutionarily conserved protein kinase that serves as a crucial signalling hub, seamlessly integrating a wide range of internal and external signals to meticulously regulate cellular and organismal physiology. TOR is crucial in regulating the different phases of the lifecycle in plants including embryogenesis, seed germination, meristem activation, root and leaf development, flowering, and senescence. Beyond its central role in growth and development, emerging research has revealed its significant involvement in the response to environmental stresses. Even though plant growth regulators such as auxin, cytokinin (CK), brassinosteroids (BR), gibberellin (GA), abscisic acid (ABA), ethylene (ET), salicylic acid (SA), jasmonic acid (JA), and nitric oxide (NO) function as pivotal signalling molecules in modulating plant development and stress responses, how they coordinate with the energy status still remains obscure. Here we summarize the current findings on the dynamic interconnection between TOR and these discrete phytoregulators, and their potential role in executing diverse biological processes in plants.