小麦DELLA获得性突变体矮变1号增强了幼苗的抗盐能力

DELLA蛋白是GA信号途径中重要的负向调控因子,能够响应各种环境信号,在植物抵抗生物和非生物胁迫中起着重要的作用。功能获得性DELLA突变体矮变1号在矮化育种上已得到广泛应用,但是其在耐盐方面的研究鲜有报道。本文采用含200 mmol L~(–1) NaCl的Hoagland水培溶液处理中国春、京411、矮秆早和矮变1号幼苗7 d,测定盐胁迫下的总叶绿素含量、相对含水量、超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量,并借助免疫印迹检测了4个小麦品种中DELLA蛋白的积累。盐胁迫处理后,矮变1号的叶片没有出现明显的萎蔫和失绿,而其他3个品种均表现出不同程度的萎蔫。盐胁迫使4个小麦品种的总叶绿素含量和相对含水量均有所下降,但矮变1号的下降幅度最小;与此同时,矮变1号体内SOD活性的相对上升幅度最大,并且体内的MDA含量相对上升幅度最小。4个品种中矮变1号的DELLA蛋白积累量最高,矮变1号具有较高的耐盐性与其体内的高DELLA蛋白含量密切相关。

AWheat DELLA Gain-of-Function Mutant Aibian 1 Promotes Seedling Salt Tolerance

DELLA proteins are negative regulators in GA signal pathway. DELLA protein is able to response to various environmental signals and plays an important role in plant resistance to biotic and abiotic stresses. The DELLA gain-of-function mutant Aibian 1 has been widely applied in wheat breeding for dwarfness, but its tolerance to salt is unclear. In this study, Aibian 1 was compared with Chinese Spring, Jing 411, and Aiganzao in salt tolerance using Hoagland’s hydroponic culture with 200 mmol L?1 NaCl. Total chlorophyll content, relative water content, superoxide dismutase (SOD) activity and malondialdehyde (MDA) content were measured to evaluate the ability of salt tolerance. Immunoblot assay was employed to assess the DELLA protein abundance in wheat seedlings. After seven-day NaCl treatment, Aibian 1 showed no clear withering leaves, whereas the other three cultivars displayed obviously wilting and yellowing leaves. Among the four cultivars, Aibian 1 had the least loss on chlorophyll content and relative water content, the highest SOD activity, and the lowest levels of MDA content after salt treatment. Immunoblot assay indicated the highest accumulation of DELLA protein in Aibian 1 among the four cultivars. Thus, we consider the high level of DELLA protein is closely related to salt tolerance in Aibian 1.