Overexpression of a small heat‐shock‐protein gene enhances tolerance to abiotic stresses in rice

Abstract Rice ( Oryza sativa L.) is one of the most important crops in the world which survives from various abiotic stresses in natural environments with specific stress‐involved genes expressed. Plant sHSP s (small heat‐shock proteins) were reported to respond to abiotic stresses. To improve the understanding of sHSP s in rice, we characterized heat‐shock‐protein gene Os HSP 18.6 here. Os HSP 18.6 could be induced by diverse stresses, such as drought, salt and cold, especially under heat. The gene was found expressed in root, stem, leaf, internode and spikelet. Overexpression of Os HSP 18.6 results in increased thermotolerance and exhibits universal tolerance to stresses tested, including heat, drought, salt and cold. Lower levels of malondialdehyde ( MDA ) and greater activities of catalase ( CAT ) and superoxide dismutase ( SOD ) were observed in Os HSP 18.6 ‐overexpression rice under heat and drought. Os HSP 18.6 ‐overexpression lines indicated decreased sterile rates under hot weather without remarkable changes in most of other agronomic traits compared with wild‐type plants.