NaHCO3胁迫下马铃薯根系代谢组差异分析

【目的】分析马铃薯根系对NaHCO3胁迫的代谢组学差异，揭示不同马铃薯品种响应NaHCO3胁迫的代谢分子机制，为优化马铃薯育种、栽培技术措施以及生产应用提供理论依据。【方法】以马铃薯‘V7’和‘康尼贝克’2个品种幼苗根系为研究对象，选用不同浓度梯度（CK、10 mmol/L、20 mmol/L、30 mmol/L、40 mmol/L、50 mmol/L）NaHCO3溶液模拟碱胁迫，胁迫7 d后，结合非靶向代谢组学检测方法，利用高效液相色谱（LC-MS）技术及多维统计学对2个马铃薯品种根系代谢产物进行检测分析。【结果】（1）NaHCO3胁迫下，‘V7’根系中检测到160种代谢物上调、91种代谢物下调，‘康尼贝克’根系中125种代谢物上调、52种代谢物下调。（2）KEGG通路富集分析表明，2个品种各筛选出10条差异代谢通路，其中植物次生代谢产物的生物合成、不饱和脂肪酸的生物合成、由组氨酸和嘌呤衍生的生物碱合成以及嘧啶代谢这4条差异代谢通路是马铃薯根系响应碱胁迫的关键代谢途径。（3）糖类、酰胺类化合物、胺类、含氧有机化合物、生物碱、酚酸类、菑体-皂苷元等差异代谢物均参与到了马铃薯响应NaHCO3胁迫的复杂的调控网络中。【结论】研究筛选出马铃薯根系响应NaHCO3胁迫的关键代谢产物以及代谢途径，耐碱性品种V7与碱敏感性品种‘康尼贝克’二者根系代谢组学存在差异性；同时，同一个品种不同胁迫程度下其根系代谢与CK也存在差异性。氨基酸及其衍生物、有机酸、尿囊素这3类差异代谢物含量的积累是‘V7’根系代谢过程活跃、耐碱性能力强于‘康尼贝克’的重要特征分子。

Difference Analysis of Potato Root Metabolome under NaHCO3 Stress

[Objective] The study aims to analyze the metabolomic differences of potato roots to NaHCO3 stress, reveal the metabolic molecular mechanism of different potato varieties in response to NaHCO3 stress, and provide theoretical basis for optimizing potato breeding, cultivation techniques and production applications. [Methods] The root system of potato ‘V7’ and ‘KANG Nibeike’ seedlings was selected as the research object, and NaHCO3 solution was used to simulate alkali stress with different concentration gradients (CK, 10 mmol/L, 20 mmol/L, 30 mmol/L, 40 mmol/L, 50 mmol/L). The root metabolites of two potato varieties were analyzed by high performance liquid chromatography (LC-MS) and multidimensional statistics combined with non-targeted metabolomics detection. [Results] (1) Under NaHCO3 stress, 160 metabolites were up-regulated and 91 metabolites were down-regulated in ‘V7’ roots, 125 metabolites were up-regulated and 52 metabolites were down-regulated in ‘KANG Nibeike’ roots. (2) KEGG pathway enrichment analysis showed that 10 differential metabolic pathways were selected for each of the two varieties, among which 4 differential metabolic pathways, namely, biosynthesis of plant secondary metabolites, biosynthesis of unsaturated fatty acids, synthesis of histidine and purine-derived alkaloids, and pyrimidine metabolism, were the key metabolic pathways in response to alkali stress in potato roots. (3) Differential metabolites such as carbohydrates, amides, amines, oxy-containing organic compounds, alkaloids, phenolic acids, somatogenin, etc. are involved in the complex regulatory network of potato response to NaHCO3 stress. [Conclusion] The key metabolites and metabolic pathways of potato root in response to NaHCO3 stress were screened out. There were differences in the root metabolomics of alkaline tolerant cultivar ‘V7’ and alkali sensitive cultivar ‘KANG Nibeike’. At the same time, there were differences between the root metabolism of the same variety and CK under different stress levels. The accumulation of amino acids and their derivatives, organic acids and allantoin is an important characteristic of ‘V7’ root metabolism, which is more active and alkaline resistant than ‘KANG Nibeike’.