Fussy Andre, Papenbrock Jutta
Institute of Botany, Leibniz University Hannover, Hannover, Germany.
Front Plant Sci. 2024 Sep 3;15:1454541. doi: 10.3389/fpls.2024.1454541. eCollection 2024.
Freshwater scarcity demands exploration of alternative resources like saline water and soils. Understanding the molecular mechanisms behind NaCl regulation in potential crop plants becomes increasingly important for promoting saline agriculture. This study investigated the euhalophyte , analyzing its gene expression, yield, and total phenolic compounds under hydroponic cultivation. We employed five salinity levels (0, 7.5, 15, 22.5, and 30 g/L NaCl) across five harvests at 15-day intervals, capturing plant development. Notably, this design deviated from conventional gene expression studies by recording organ-specific responses (shoots and roots) in plants adapted to long-term salinity treatments at various developmental stages. The highest fresh mass of was observed four months after germination in 15 g/L NaCl. Identifying a reliable set of reference genes for normalizing gene expression data was crucial due to comparisons across shoots, roots, developmental stages, and salinity levels. A set of housekeeping genes - ubiquitin c (), actin () and dnaJ-like protein () - was identified for this purpose. Interestingly, plants grown without NaCl (0 g/L) displayed upregulation of certain genes associated with a NaCl deficiency related nutritional deprivation. These genes encode a tonoplast Na/H-antiporter (, a vacuolar H-ATPase (), two H-PPases (, ), a hkt1-like transporter (), a vinorine synthase (), a peroxidase (), and a plasma membrane Na/H-antiporter (). Other genes encoding an amino acid permease () and a proline transporter () demonstrated marginal or dispersing salinity influence, suggesting their nuanced regulation during plants development. Notably, osmoregulatory genes (, ) were upregulated in mature plants, highlighting their role in salinity adaptation. This study reveals distinct regulatory mechanisms in for coping with varying salinity levels. Identifying and understanding physiological reactions and sodium responsive key genes further elucidate the relationship between sodium tolerance and the obligate sodium requirement as a nutrient in euhalophytes.
淡水短缺促使人们探索诸如咸水和土壤等替代资源。了解潜在作物中氯化钠调节背后的分子机制对于促进盐碱农业变得越来越重要。本研究对真盐生植物进行了调查，分析了其在水培条件下的基因表达、产量和总酚类化合物。我们在五个收获期（间隔15天）采用了五个盐度水平（0、7.5、15、22.5和30 g/L氯化钠），以记录植物的生长发育情况。值得注意的是，该设计与传统基因表达研究不同，它记录了在不同发育阶段适应长期盐度处理的植物的器官特异性反应（地上部分和根部）。在15 g/L氯化钠处理下，发芽四个月后观察到最高鲜重。由于要对地上部分、根部、发育阶段和盐度水平进行比较，因此确定一组可靠的参考基因来标准化基因表达数据至关重要。为此，鉴定出了一组管家基因——泛素c（）、肌动蛋白（）和类dnaJ蛋白（）。有趣的是，在无氯化钠（0 g/L）条件下生长的植物中，某些与氯化钠缺乏相关营养剥夺有关的基因出现上调。这些基因编码液泡膜Na/H反向转运蛋白（）、液泡H-ATP酶（）、两个H-PP酶（，）、一个类hkt1转运蛋白（）、一个长春花碱合酶（）、一个过氧化物酶（）和一个质膜Na/H反向转运蛋白（）。其他编码氨基酸通透酶（）和脯氨酸转运蛋白（）的基因显示出轻微或分散的盐度影响，表明它们在植物发育过程中的调控较为细微。值得注意的是，渗透调节基因（，）在成熟植物中上调，突出了它们在盐度适应中的作用。本研究揭示了真盐生植物应对不同盐度水平的独特调控机制。识别和理解生理反应以及钠响应关键基因进一步阐明了真盐生植物中耐钠性与作为养分的必需钠需求之间的关系。
