Calone Roberta, Sanoubar Rabab, Lambertini Carla, Speranza Maria, Antisari Livia Vittori, Vianello Gilmo, Barbanti Lorenzo
Department of Agricultural and Food Sciences (DISTAL), University of Bologna, 40127 Bologna, Italy.
Plants (Basel). 2020 Apr 28;9(5):561. doi: 10.3390/plants9050561.
Salinity is a major constraint for plant growth in world areas exposed to salinization. (L.) Moench is a species that has received attention for biomass production in saline areas thanks to drought and salinity tolerance. To improve the knowledge in the mechanisms of salt tolerance and sodium allocation to plant organs, a pot experiment was set up. The experimental design combined three levels of soil salinity (0, 3, and 6 dS m) with three levels of water salinity (0, 2-4, and 4-8 dS m) and two water regimes: no salt leaching (No SL) and salt leaching (SL). This latter regime was carried out with the same three water salinity levels and resulted in average +81% water supply. High soil salinity associated with high water salinity (HSS-HWS) affected plant growth and final dry weight (DW) to a greater extent in No SL (-87% DW) than SL (-42% DW). Additionally, HSS-HWS determined a stronger decrease in leaf water potential and relative water content under No SL than SL. HSS-HWS with No SL resulted in a higher Na bioaccumulation from soil to plant and in translocation from roots to stem and, finally, leaves, which are the most sensitive organ. Higher water availability (SL), although determining higher salt input when associated with HWS, limited Na bioaccumulation, prevented Na translocation to leaves, and enhanced selective absorption of Ca vs. Na. At plant level, higher Na accumulation was associated with lower Ca and Mg accumulation, especially in No SL. This indicates altered ion homeostasis and cation unbalance.
盐分是世界上受盐渍化影响地区植物生长的主要限制因素。盐角草是一种因耐旱和耐盐性而在盐碱地生物质生产方面受到关注的物种。为了增进对耐盐机制和植物器官中钠分配的了解，开展了一项盆栽试验。试验设计将三种土壤盐分水平（0、3和6 dS/m）与三种水盐分水平（0、2 - 4和4 - 8 dS/m）以及两种水分管理方式相结合：无盐分淋洗（无SL）和盐分淋洗（SL）。后一种管理方式采用相同的三种水盐分水平，平均供水量增加了81%。高土壤盐分与高水盐分（HSS - HWS）相结合，在无SL条件下（干重减少87%）比在SL条件下（干重减少42%）对植物生长和最终干重（DW）的影响更大。此外，HSS - HWS导致无SL条件下叶片水势和相对含水量的下降幅度比SL条件下更大。无SL的HSS - HWS导致从土壤到植物的钠生物积累更高，并且从根向茎以及最终向最敏感的器官叶片的转运增加。更高的水分可利用性（SL），尽管与高水盐分结合时会导致更高的盐分输入，但限制了钠的生物积累，阻止了钠向叶片的转运，并增强了对钙与钠的选择性吸收。在植物水平上，更高的钠积累与更低的钙和镁积累相关，尤其是在无SL条件下。这表明离子稳态改变和阳离子失衡。
