The use of humic substances as plant biostimulants has been increasingly attracting farmers and stunning researchers. The ability of these substances to enhance root growth by changing root architecture is often linked to their hormonal activities, such as auxin effects and nitric oxide production. Humeomics accesses the molecular constituents of humic substances, revealing the importance of alkyl components because of their conformations and chemical activities. Here, we describe the alkamides present in humic acids and compare their bioactivities using plasma membrane H+-ATPase activity level as a biochemical marker. Humic acids isolated from vermicompost were analyzed using 13C and 15N nuclear magnetic resonance spectroscopy. The unbound fraction was extracted with ethyl acetate and submitted to gas chromatography coupled to mass spectrometry to detect the presence of N-isopropyldecanamide. We synthesized N-isopropyldecanamide and treated maize seedlings for 7 and 15 days with different concentrations. The root growth and plasma membrane H+-ATPase activity were monitored. Nitric oxide accumulation in the lateral roots was imaged using 4,5-diaminofluorescein diacetate. The results were compared with those obtained for seedlings treated with humic acids isolated from vermicompost. The amide functional group produced the only nitrogen signal in the 15N humic acid resonance spectrum and similar alkamide moieties were found in the unbound humic extract through comparisons using gas chromatography coupled to mass spectrometry. The synthesis of N-isopropyldecanamide had few steps and produced a high yield (86%). The effects of N-isopropyldecanamide on root growth were concentration dependent. High concentrations (10−4 M) enhanced root growth after 15 day of diminishing shoot biomass. However, low concentrations (10−8 M and 10−6 M) promoted root growth at 7 and 15 days, similar to the humic acid-induced plasma membrane H+-ATPase activity. Both N-isopropyldecanamide and humic acids enhanced nitric oxide accumulation during lateral root emergence. We described for the first time the effects of N-isopropyldecanamide on the plasma membrane H+-ATPase activity in maize seedling roots and compared its effects with those caused by humic acids. N-Isopropyldecanamide was detected in the unbound fraction of the humic supramolecular assembly, indicating that the putative hormone-like effects of these substances result also from the presence of this new class of plant regulators, in addition to other molecules.

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烷基酰胺：与腐殖酸生物活性有关的新型植物生长调节剂

腐殖质作为植物生物刺激剂的使用越来越吸引农民和出色的研究人员。这些物质通过改变根系结构而增强根系生长的能力通常与它们的激素活性有关，例如生长素的作用和一氧化氮的产生。Humeomics访问腐殖质的分子成分，揭示了烷基成分的重要性，因为它们的构象和化学活性。在这里，我们描述了腐殖酸中存在的链酰胺，并使用质膜H + -ATPase活性水平作为生化标记来比较它们的生物活性。使用13 C和15 N核磁共振波谱分析了从ver虫中分离出的腐殖酸。未结合的级分用乙酸乙酯萃取，并进行气相色谱与质谱联用，以检测N-异丙基癸酰胺的存在。我们合成了N-异丙基癸酰胺，并以不同的浓度处理了7天和15天的玉米幼苗。监测根生长和质膜H + -ATPase活性。使用4，5-二氨基荧光素二乙酸酯对侧根中一氧化氮的积累进行成像。将结果与从腐殖土中分离的腐殖酸处理过的幼苗的结果进行比较。酰胺官能团在15N腐殖酸共振谱中产生了唯一的氮信号，并且通过使用气相色谱-质谱联用的比较，在未结合的腐殖提取物中发现了类似的烷酰胺部分。N-异丙基癸酰胺的合成步骤少，产率高（86％）。N-异丙基癸酰胺对根生长的影响是浓度依赖性的。茎生物量减少15天后，高浓度（10-4 M）增强了根的生长。但是，低浓度（10-8 M和10-6 M）在7天和15天促进根生长，类似于腐殖酸诱导的质膜H + -ATPase活性。N-异丙基癸酰胺和腐殖酸均会在侧根出苗时增加一氧化氮的积累。我们首次描述了N-异丙基癸酰胺对玉米幼苗根系质膜H + -ATPase活性的影响，并将其与腐殖酸的影响进行了比较。在腐殖质超分子组装体的未结合部分中检测到N-异丙基癸酰胺，