Braga Ítalo de Oliveira, Carvalho da Silva Thalliton Luiz, Belo Silva Vivianny Nayse, Rodrigues Neto Jorge Candido, Ribeiro José Antônio de Aquino, Abdelnur Patrícia Verardi, de Sousa Carlos Antônio Ferreira, Souza Manoel Teixeira
Graduate Program of Plant Biotechnology, Federal University of Lavras, Lavras, Brazil.
Institute of Chemistry, Federal University of Goiás, Campus Samambaia, Goiânia, Brazil.
Front Plant Sci. 2022 May 19;13:869105. doi: 10.3389/fpls.2022.869105. eCollection 2022.
The multipurpose tree (Jacq.) Walp. adapts to a very high level of salt stress (≥20 dS m) and resumes the production of new leaves around 2 weeks after losing all leaves due to abrupt salinity stress. The integration of metabolome and transcriptome profiles from gliricidia leaves points to a central role of the phenylpropanoid biosynthesis pathway in the short-term response to salinity stress. In this study, a deeper untargeted metabolomics analysis of the leaves and roots of young gliricidia plants was conducted to characterize the mechanism(s) behind this adaptation response. The polar and lipidic fractions from leaf and root samples were extracted and analyzed on a UHPLC.ESI.Q-TOF.HRMS system. Acquired data were analyzed using the XCMS Online, and MetaboAnalyst platforms, three distinct and complementary strategies. Together, the results obtained first led us to postulate that these plants are salt-excluding plants, which adapted to high salinity stress two salt-excluding mechanisms, starting in the canopy-severe defoliation-and concluding in the roots-limited entry of Na. Besides that, it was possible to show that the phenylpropanoid biosynthesis pathway plays a role throughout the entire adaptation response, starting in the short term and continuing in the long one. The roots metabolome analysis revealed 11 distinct metabolic pathways affected by salt stress, and the initial analysis of the two most affected ones-steroid biosynthesis and lysine biosynthesis-led us also to postulate that the accumulation of lignin and some phytosterols, as well as lysine biosynthesis-but not degradation, play a role in promoting the adaptation response. However, additional studies are necessary to investigate these hypotheses.
多用途树（Gliricidia sepium (Jacq.) Walp.）能适应非常高的盐胁迫水平（≥20 dS m），并且在因突然的盐胁迫而失去所有叶片后约2周左右恢复新叶的生长。对葛藤叶的代谢组和转录组图谱进行整合分析表明，苯丙烷生物合成途径在对盐胁迫的短期响应中起核心作用。在本研究中，对年轻葛藤植株的叶和根进行了更深入的非靶向代谢组学分析，以表征这种适应反应背后的机制。从叶和根样品中提取极性和脂质部分，并在超高效液相色谱-电喷雾-四极杆飞行时间-高分辨率质谱系统（UHPLC.ESI.Q-TOF.HRMS）上进行分析。使用XCMS Online和MetaboAnalyst平台这三种不同且互补的策略对获得的数据进行分析。综合来看，首先获得的结果使我们推测这些植物是拒盐植物，它们通过两种拒盐机制适应高盐胁迫，起始于地上部分——严重落叶，终结于根部——限制钠的进入。除此之外，还能够表明苯丙烷生物合成途径在整个适应反应中都发挥作用，从短期开始并持续到长期。根部代谢组分析揭示了11条受盐胁迫影响的不同代谢途径，对受影响最大的两条途径——类固醇生物合成和赖氨酸生物合成的初步分析也使我们推测木质素和一些植物甾醇的积累以及赖氨酸的生物合成——而非降解，在促进适应反应中发挥作用。然而，需要进一步的研究来探究这些假设。
