Shandong Provincial Key Laboratory of Plant Stress, College of Life Science, Shandong Normal University, Cnan, 250014, PR China.
Shandong Provincial Key Laboratory of Plant Stress, College of Life Science, Shandong Normal University, Cnan, 250014, PR China.
Plant Physiol Biochem. 2021 Feb;159:171-178. doi: 10.1016/j.plaphy.2020.12.024. Epub 2020 Dec 24.
The global annual loss in agricultural production resulting from soil salinization is significant. Although nitrate (NO) is known to play both nutritional and osmotic roles in the salt tolerance of halophytes, it remains unclear how halophytes such as Suaeda salsa L. take up NO under saline conditions. In the present study, the gene of nitrate transporter 2.1 (SsNRT2.1) was cloned from S. salsa and its function was identified in both S. salsa and Arabidopsis thaliana under salinity and low NO-N (0.5 mM NO) conditions. The results revealed that SsNRT2.1 expression and NO concentration in the roots of S. salsa were higher at 200 mM NaCl, compared with that at 0 and 500 mM NaCl after 24 h treatment. The Arabidopsis overexpression lines showed a higher NO content compared to the WT lines at 0 and 50 mM NaCl. A similar trend was observed in the root length. In conclusion, salinity promoted the SsNRT2.1 expression in S. salsa, suggesting that this gene may contribute to the efficient NO uptake in S. salsa under low NO and high salinity conditions. This trait may explain why S. salsa can tolerate high salinity and produce the highest biomass at about 200 mM NaCl.
土壤盐渍化导致全球农业生产每年损失巨大。虽然硝酸盐（NO）在盐生植物的耐盐性中具有营养和渗透作用，但盐生植物（如盐地碱蓬）在盐胁迫下如何吸收 NO 仍不清楚。本研究从盐地碱蓬中克隆了硝酸盐转运蛋白 2.1（SsNRT2.1）基因，并在盐胁迫和低 NO-N（0.5 mM NO）条件下在盐地碱蓬和拟南芥中鉴定了其功能。结果表明，与 0 和 500 mM NaCl 处理 24 h 后相比，200 mM NaCl 处理 24 h 后盐地碱蓬根中 SsNRT2.1 表达和 NO 浓度更高。在 0 和 50 mM NaCl 条件下，拟南芥过表达系的 NO 含量高于 WT 系。根长也呈现出类似的趋势。综上所述，盐度促进了盐地碱蓬中 SsNRT2.1 的表达，表明该基因可能有助于盐地碱蓬在低 NO 和高盐条件下高效吸收 NO。这种特性可以解释为什么盐地碱蓬可以耐受高盐度，并在约 200 mM NaCl 时产生最高的生物量。
