Molecular insight into auxin signaling and associated network modulating stress responses in rice

Phytohormones are vital regulators of various signaling networks in plants. Among different phytohormones, auxin has been thoroughly studied for its role in regulating plants' growth, development, and stress response. One major function of auxin is modulating the developmental processes in response to environmental cues. Although extensive studies on Arabidopsis have advanced the knowledge of auxin biology, several studies on rice have uncovered key players regulated by auxin that play critical roles in coordinating auxin homeostasis and signaling involved in defense response. The emerging knowledge on auxin biology, auxin-regulated gene expression, and auxin-signaling in rice during various environmental stresses has provided insights into the possible mechanism of rice susceptibility or resistance to different abiotic and biotic stresses. The current review enumerates the possible mechanisms of stress-induced auxin homeostasis in rice. In addition, we provide an overview of the state of knowledge on auxin-mediated defense signaling in rice, highlighting its pivotal role in stress response. In particular, we discuss the auxin pathways and the dynamic regulation in response to biotic and abiotic stress. We highlight the novel findings in the diversity of auxin signaling in the model plant Arabidopsis with an aim to emphasize the need to translate these findings into agronomically and economically important cereals like rice. Addressing the complexity of auxin induction, signaling, and its associated molecular network, an in-depth investigation in rice is required to comprehend auxin-mediated spatial-temporal regulation of developmental processes during stress.