Comprehensive Profiling of the Rice OsEPF/EPFL Gene Family Under Biotic and Abiotic Stresses Reveals the Involvement of OsEPF2 in Disease Resistance.

Members of the EPIDERMAL PATTERNING FACTOR (EPF) and EPF-Like (EPFL) families perform diverse regulatory functions in plant tissue morphogenesis, controlling the development of stomata, awns, shoot apical meristems (SAMs), and inflorescences. Nevertheless, the biological functions of OsEPF/EPFL family members in mediating responses to biotic/abiotic stresses are not yet widely characterized. Here, we demonstrated abundant cis-acting elements in the putative promoters of OsEPF/EPFL genes, including those associated with dehydration-, MeJA-, MYB binding site for drought, stress-, and ABA-responsive element. We performed a systematic analysis of the expression patterns of all OsEPF/EPFL family members under heat, cold, drought, and salt stress treatments. Among these genes, OsEPFL9 and OsEPFL10 exhibited rapid and sustained up-regulation across all four stress conditions. Furthermore, the majority of OsEPF/EPFL members were up-regulated specifically in response to salt stress. In terms of biotic stress responses, OsEPF2/5/7/10 were rapidly induced as early as 12 h post-infection (hpi) with the rice blast pathogen (Magnaporthe oryzae). Functional validation further revealed that its deficiency causes increased sensitivity to both M. oryzae and Xanthomonas oryzae pv. oryzae (Xoo). Collectively, our research will provide significant insights into the multifunctional roles of the OsEPF/EPFL gene family, particularly in stress responses. This work also establishes a theoretical basis and scientific reference for the application of plant small secreted peptides (SSPs) in crop disease resistance breeding and stress tolerance improvement.