OsCEP8-mediated abiotic stress response is associated with auxin and sugar homeostasis in plants

Abstract

Plants are exposed to various abiotic stresses in natural environmental conditions such as drought, salinity, etc., which have a detrimental impact on crop yield. Therefore, understanding the signalling mechanism under abiotic stress will help us to engineer a crop tolerant to these abiotic stress conditions. Here, we studied the role of a signaling peptide, a C-terminally Encoded Peptide (CEP), in response to abiotic stress conditions. In this study, a stress-responsive member of the CEP gene family, OsCEP8, was characterized. The study revealed the pivotal involvement of a specific OsCEP8 gene in enhancing tolerance towards abiotic stress in transgenic rice and Arabidopsis plants. Furthermore, we have demonstrated that under nutrient and mineral deficient conditions such as nitrogen and sugar deficiency, the OsCEP8 overexpressing transgenic Arabidopsis plants show an increase in primary and lateral root length. Moreover, this OsCEP8-mediated abiotic stress response regulates the auxin concentration in plants. The T-DNA insertion mutant of Arabidopsis, cep8 exhibited low active auxin levels, and stress-responsive genes were downregulated in this mutant. Further, the expression of genes involved in the KIN10/SnRK1 pathway, such as bZIP2 and bZIP11, upregulated in OsCEP8 overexpressing Arabidopsis plants. Thus, we proposed that OsCEP8 mediated response directs redistribution of metabolic resources such as auxin to enhance resistance towards abiotic conditions.