Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China.
College of Landscape Architecture, Northeast Forestry University, Harbin 150040, China.
Int J Environ Res Public Health. 2020 May 26;17(11):3770. doi: 10.3390/ijerph17113770.
Exogenous hormones play an important role in plant growth regulation and stress tolerance. However, little is known about the effect of exogenous abscisic acid (ABA) on wheat seedlings under salt and alkali stresses. Here, a pot experiment of saline and alkaline stresses (0 and 100 mmol/L) in which ABA water solution (0, 50 and 100 μmol/L) was sprayed on wheat seedlings was conducted to study the alleviative effectiveness of ABA on salt and alkali stresses. After spraying ABA (50 μmol·L), shoot biomass increased 19.0% and 26.7%, respectively. The Na content in shoots reduced from 15-fold and 61.5-fold to 10-fold and 37.3-fold in salt and alkali stresses, compared to controls. In addition, proline and organic acid synthesis in shoots also reduced significantly, but the soluble sugar content increased under alkali stress. A high concentration of ABA (100 μmol·L) had no significant effects on biomass and ion content in wheat seedlings under both stresses. In conclusion, foliar application of ABA with moderate concentration could effectively accelerate shoot growth of salt-induced wheat seedlings by adjusting the levels of ions and organic solutes.
外源激素在植物生长调节和胁迫耐受中起着重要作用。然而，外源脱落酸（ABA）对盐碱胁迫下小麦幼苗的影响知之甚少。本研究采用盆栽模拟盐碱性胁迫（0 和 100mmol/L），喷施不同浓度 ABA（0、50 和 100μmol/L）溶液，研究 ABA 对盐碱性胁迫的缓解效果。喷施 ABA（50μmol·L）后，小麦幼苗地上部生物量分别增加了 19.0%和 26.7%。与对照相比，盐碱性胁迫下小麦幼苗地上部 Na 含量分别降低至对照的 10 倍和 37.3 倍，碱胁迫下地上部 Na 含量降低至对照的 61.5 倍。此外，盐碱性胁迫下，幼苗地上部脯氨酸和有机酸的合成显著减少，但碱胁迫下可溶性糖含量增加。高浓度 ABA（100μmol·L）对两种胁迫下小麦幼苗生物量和离子含量无显著影响。综上所述，叶面喷施适宜浓度的 ABA 可以通过调节离子和有机溶质的水平，有效促进盐胁迫下小麦幼苗地上部的生长。
