Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China.
J Integr Plant Biol. 2011 Dec;53(12):951-60. doi: 10.1111/j.1744-7909.2011.01087.x.
Dehydration-responsive element binding (DREB) proteins are a subfamily of AP2/ERF transcription factors that have been shown to improve tolerance to osmotic stresses in plants. To improve the osmotic stress tolerance of paper mulberry (Broussonetia papyrifera L. Vent), an economically important tree, we transformed it with a plasmid carrying tall fescue (Festuca arundinacea Schreb) FaDREB2 under the control of CaMV 35S. The ectopic expression of FaDREB2 did not cause growth retardation, and the paper mulberry seedlings expressing FaDREB2 showed higher salt and drought tolerance than wild-type plants (WT). After 13 d of withholding water, or 15 d in the presence of 250 mM NaCl, all the WT plants died, while the plants expressing FaDREB2 survived. The FaDREB2 transgenic plants had higher leaf water and chlorophyll contents, accumulated more proline and soluble sugars, and had less membrane damage than the WT plants under high salt and water-deficient conditions. Taken together, the results indicate the feasibility of improving tolerance to multiple environmental stresses in paper mulberry seedlings via genetic engineering, by introducing FaDREB2, which promotes the increased accumulation of osmolytes (soluble sugars and proline), to counter osmotic stresses caused by abiotic factors.
脱水响应元件结合蛋白（DREB）是 AP2/ERF 转录因子的一个亚家族，已被证明能提高植物对渗透胁迫的耐受性。为了提高造纸桑树（Broussonetia papyrifera L. Vent）的耐渗透胁迫能力，这是一种具有经济重要性的树种，我们将携带高羊茅（Festuca arundinacea Schreb）FaDREB2 的质粒转化为 CaMV 35S 控制下的造纸桑树。FaDREB2 的异位表达不会导致生长迟缓，表达 FaDREB2 的造纸桑树幼苗比野生型植物（WT）表现出更高的耐盐性和耐旱性。在停水 13 天后，或在 250 mM NaCl 存在下 15 天后，所有 WT 植物均死亡，而表达 FaDREB2 的植物存活。在高盐和缺水条件下，FaDREB2 转基因植物的叶片水分和叶绿素含量较高，脯氨酸和可溶性糖积累较多，膜损伤较少。综上所述，结果表明，通过遗传工程引入 FaDREB2 可以提高造纸桑树幼苗对多种环境胁迫的耐受性，FaDREB2 促进了渗透胁迫下渗透物质（可溶性糖和脯氨酸）的积累，从而抵抗非生物因素引起的渗透胁迫。
