Song Tingting, Xu Huihui, Sun Na, Jiang Liu, Tian Pu, Yong Yueyuan, Yang Weiwei, Cai Hua, Cui Guowen
College of Animal Sciences and Technology, Northeast Agricultural UniversityHarbin, China.
College of Life Sciences, Northeast Agricultural UniversityHarbin, China.
Front Plant Sci. 2017 Jul 11;8:1208. doi: 10.3389/fpls.2017.01208. eCollection 2017.
Alkaline salts (e.g., NaHCO and NaCO) causes more severe morphological and physiological damage to plants than neutral salts (e.g., NaCl and NaSO) due to differences in pH. The mechanism by which plants respond to alkali stress is not fully understood, especially in plants having symbotic relationships such as alfalfa ( L.). Therefore, a study was designed to evaluate the metabolic response of the root-nodule symbiosis in alfalfa under alkali stress using comparative metabolomics. Rhizobium-nodulized (RI group) and non-nodulized (NI group) alfalfa roots were treated with 200 mmol/L NaHCO and, roots samples were analyzed for malondialdehydyde (MDA), proline, glutathione (GSH), superoxide dismutase (SOD), and peroxidase (POD) content. Additionally, metabolite profiling was conducted using gas chromatography combined with time-of-flight mass spectrometry (GC/TOF-MS). Phenotypically, the RI alfalfa exhibited a greater resistance to alkali stress than the NI plants examined. Physiological analysis and metabolic profiling revealed that RI plants accumulated more antioxidants (SOD, POD, GSH), osmolytes (sugar, glycols, proline), organic acids (succinic acid, fumaric acid, and alpha-ketoglutaric acid), and metabolites that are involved in nitrogen fixation. Our pairwise metabolomics comparisons revealed that RI alfalfa plants exhibited a distinct metabolic profile associated with alkali putative tolerance relative to NI alfalfa plants. Data provide new information about the relationship between non-nodulized, rhizobium-nodulized alfalfa and alkali resistance.
由于pH值的差异，碱性盐（如NaHCO₃和Na₂CO₃）对植物造成的形态和生理损伤比中性盐（如NaCl和Na₂SO₄）更严重。植物对碱胁迫的响应机制尚未完全了解，尤其是在具有共生关系的植物中，如紫花苜蓿（Medicago sativa L.）。因此，本研究旨在通过比较代谢组学评估碱胁迫下紫花苜蓿根瘤共生体的代谢反应。用200 mmol/L NaHCO₃处理结瘤（RI组）和未结瘤（NI组）的紫花苜蓿根，分析根样品中丙二醛（MDA）、脯氨酸、谷胱甘肽（GSH）、超氧化物歧化酶（SOD）和过氧化物酶（POD）的含量。此外，使用气相色谱结合飞行时间质谱（GC/TOF-MS）进行代谢物谱分析。从表型上看，RI紫花苜蓿比所检测的NI植物对碱胁迫表现出更强的抗性。生理分析和代谢谱分析表明，RI植物积累了更多的抗氧化剂（SOD、POD、GSH）、渗透调节物质（糖、糖醇、脯氨酸）、有机酸（琥珀酸、富马酸和α-酮戊二酸）以及参与固氮的代谢物。我们的成对代谢组学比较表明，相对于NI紫花苜蓿植物，RI紫花苜蓿植物表现出与假定的碱耐受性相关的独特代谢谱。数据提供了有关未结瘤、根瘤菌结瘤的紫花苜蓿与抗碱性之间关系的新信息。
