Abstract
Abstract Background 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. Methods Humic acids isolated from vermicompost were analyzed using 13 C and 15 N 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. Results The amide functional group produced the only nitrogen signal in the 15 N 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. Conclusion 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.
Abstract from the paper’s OpenAlex record; open copy licensed cc-by. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 8
Claim · model-written summary
N -isopropyldecanamide was detected in humic extract.
Zea maysOrganisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“similar alkamide moieties were found in the unbound humic extract”
e1“treated maize seedlings”
Claim · model-written summary
N -isopropyldecanamide synthesis yielded 86%.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The synthesis of N -isopropyldecanamide had few steps and produced a high yield (86%)”
e1“treated maize seedlings”
Claim · model-written summary
Alkamide effects on maize root growth depended on concentration.
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The effects of N -isopropyldecanamide on root growth were concentration dependent”
e1“treated maize seedlings”
Claim · model-written summary
High alkamide concentration enhanced root growth after 15 days.
- Treatment
- High concentrations (10 −4 M)e0
- Outcome
- root growthe0
- Direction
- enhancede0
- Qualifier
- after 15 daye0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“High concentrations (10 −4 M) enhanced root growth after 15 day of diminishing shoot biomass”
e1“treated maize seedlings”
Claim · model-written summary
High alkamide concentration diminished shoot biomass.
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“High concentrations (10 −4 M) enhanced root growth after 15 day of diminishing shoot biomass”
e1“treated maize seedlings”
Claim · model-written summary
Low alkamide concentrations promoted root growth at 7 and 15 days.
- Treatment
- low concentrations (10 −8 M and 10 −6 M)e0
- Outcome
- root growthe0
- Direction
- promotede0
- Qualifier
- 7 and 15 dayse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“low concentrations (10 −8 M and 10 −6 M) promoted root growth at 7 and 15 days”
e1“treated maize seedlings”
Claim · model-written summary
N -isopropyldecanamide enhanced nitric oxide accumulation during lateral root emergence.
- Organ / stage
- lateral root emergencee0
- Treatment
- N -isopropyldecanamidee0
- Outcome
- nitric oxide accumulatione0
- Direction
- enhancede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Both N -isopropyldecanamide and humic acids enhanced nitric oxide accumulation during lateral root emergence”
e1“treated maize seedlings”
Claim · model-written summary
Humic acids enhanced nitric oxide accumulation during lateral root emergence.
- Organ / stage
- lateral root emergencee0
- Treatment
- humic acidse0
- Outcome
- nitric oxide accumulatione0
- Direction
- enhancede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Both N -isopropyldecanamide and humic acids enhanced nitric oxide accumulation during lateral root emergence”
e1“treated maize seedlings”
The same questions in other papers
other · molecular: metabolites · Zea mays (maize)Positive and negative results
36 papers in the same direction as this paper · 2 in the opposite direction
- positive
- no effect
- no effect
35 papers more in this group
See all 39 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.