OsERF71 confers drought tolerance via modulating ABA signaling and proline biosynthesis.

Plants have evolved multiple protective strategies to adapt to adverse environmental conditions. Upland rice (UR) has evolved as a "drought-resistant type". However, little is known about genes or mechanisms in UR that underlying drought tolerance at the molecular level. Here we report isolation and functional characterization of the ERF gene, OsERF71, from the UR variety, IRAT109. The expression of OsERF71 was induced by abscisic acid (ABA) and various abiotic stresses preferentially in IRAT109 under ABA, dehydration, and polyethyleneglycol (PEG) treatments. OsERF71 was verified as a nuclear-localized protein and had transcriptional activity in yeast cells. Overexpression of the OsERF71 in Nipponbare demonstrated a significant increase in tolerance to drought stress and a reduced rate of water loss. In contrast, OsERF71 interference lines were sensitive to drought stress and exhibited a higher rate of water loss. OsERF71-overexpressing lines also showed enhanced tolerance to high salinity. Moreover, OsERF71 regulated the expression of several ABA- responsive and proline biosynthesis genes under drought stress, resulting in enhanced sensitivity to exogenous ABA treatment and proline accumulation. Accordingly, we suggest that OsERF71 plays a positive role in drought stress tolerance by increasing the expression of genes associated with ABA signaling and proline biosynthesis under stress.