Pretreating poplar cuttings with low nitrogen ameliorates salt stress responses by increasing stored carbohydrates and priming stress signaling pathways
Pretreating poplar cuttings with low nitrogen ameliorates salt stress responses by increasing stored carbohydrates and priming stress signaling pathways
复制标题
用低氮预处理杨树插条可通过增加储存的碳水化合物和启动应激信号通路来改善盐胁迫反应
DOI：
10.1016/j.ecoenv.2021.112801
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发表时间：
2021-09-21
影响因子：
6.8
通讯作者：
Yao, Yinan
中科院分区：
文献类型：
--
作者：
Gao, Yongfeng;Sun, Yufang;Yao, Yinan
土壤盐分是全球半干旱森林中普遍存在的一种胁迫，但如何管理氮素营养以提高植物的耐盐性仍不清楚。在半控制温室条件下，对分布广泛的中亚杨树插条进行了低氮(LN)和中等氮(LN)浓度处理两周，然后分别在中等浓度和不加盐条件下处理两周，观察其生理生化、代谢产物和转录谱的变化。LN处理减轻了随后的盐胁迫对杨树的毒害，表现为显著减少了Na+和Cl-的内流，提高了K+/Na+比值。其他盐胁迫性状也得到了改善，表现为叶绿素含量、PSII光化学活性和膜脂过氧化作用的变化。应力缓解由两个不同的过程产生。首先，LN处理引起非结构性碳水化合物(NSC)的显著增加，从而增加了渗透调节物质的产生，在随后的盐条件下具有更高的促进离子运输的潜力，并增加了阳离子/H+ATPase的转录水平。其次，LN处理提高了胁迫信号成分和植物激素途径的转录水平以及抗氧化酶活性。结果表明，早期限制氮素供应可以提高杨树在盐分胁迫下的后期存活率，这对半干旱地区的人工林规划和恢复活动具有重要意义。
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.