1. Pretreating poplar cuttings with low nitrogen ameliorates salt stress responses by increasing stored carbohydrates and priming stress signaling pathways.
- Author
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Gao, Yongfeng, Sun, Yufang, Ou, Yongbin, Zheng, Xinhua, Feng, Qian, Zhang, Hao, Fei, Yang, Luo, Jie, Resco de Dios, Víctor, and Yao, Yinan
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CELLULAR signal transduction ,CARBOHYDRATES ,POPLARS ,SOIL salinity ,SALT ,CHLOROPHYLL spectra ,DENTAL glass ionomer cements ,BRASSINOSTEROIDS - Abstract
Soil salinity is a widespread stress in semi-arid forests worldwide, but how to manage nitrogen (N) nutrition to improve plant saline tolerance remains unclear. Here, the cuttings of a widely distributed poplar from central Asia, Populus russikki Jabl., were exposed to either normal or low nitrogen (LN) concentrations for two weeks in semi-controlled greenhouse, and then they were added with moderate salt solution or not for another two weeks to evaluate their physiological, biochemical, metabolites and transcriptomic profile changes. LN-pretreating alleviated the toxicity caused by the subsequent salt stress in the poplar plants, demonstrated by a significant reduction in the influx of Na
+ and Cl- and improvement of the K+ /Na+ ratio. The other salt-stressed traits were also ameliarated, indicated by the variations of chlorophyll content, PSII photochemical activity and lipid peroxidation. Stress alleviation resulted from two different processes. First, LN pretreatment caused a significant increase of non-structural carbohydrates (NSC), allowed for an increased production of osmolytes and a higher potential fueling ion transport under subsequent salt condition, along with increased transcript levels of the cation/H+ ATPase. Second, LN pretreatment enhanced the transcript levels of stress signaling components and phytohormones pathway as well as antioxidant enzyme activities. The results indicate that early restrictions of N supply could enhance posterior survival under saline stress in poplar plants, which is important for plantation programs and restoration activities in semi-arid areas. [Display omitted] • Low nitrogen (LN) pretreating alleviated the toxicity caused by the subsequent salt stress in poplar. • LN pretreatment build non-structural carbohydrates (NSC) storage beneficial for the subsequent salt stress. • Cross tolerance for the following salt stress by LN pretreatment. • LN-caused metabolic priming for the following salt stress revealed by the global transciptome profile change. [ABSTRACT FROM AUTHOR]- Published
- 2021
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