2025
Martínez, D. N.; de la Barrera, E.
Enzymatic activity responses to transport and low-temperature storage: implication for plant nitrogen metabolism studies Journal Article
In: Nitrogen, vol. 6, 2025, ISBN: 2504-3129.
Abstract | Links | BibTeX | Tags: disturbance, neotropical, nitrate reductase, nitrogen deposition, phosphorus, planetary boundaries, plant nutrition, tropical forest, urban ecology
@article{Martínez2025,
title = {Enzymatic activity responses to transport and low-temperature storage: implication for plant nitrogen metabolism studies},
author = {D. N. Martínez and E. de la Barrera},
url = {https://www.mdpi.com/2504-3129/6/1/5
https://agro.mx/wp-content/uploads/2025/01/077-Martinez-N-cold-enzymes.pdf},
doi = {10.3390/nitrogen6010005},
isbn = {2504-3129},
year = {2025},
date = {2025-01-16},
urldate = {2025-01-16},
journal = {Nitrogen},
volume = {6},
abstract = {Understanding how transport and storage conditions affect enzymatic activity is essential for accurate biomonitoring of nitrogen metabolism in plants. This study evaluated the effects of transport conditions and low-temperature storage on the enzymatic activities of nitrate reductase (NR), glutamine synthetase (GS), and phosphomonoesterase (PME) for Chloris gayana, Fraxinus uhdei, and Trifolium repens. Enzymatic activities were measured for leaf samples immediately after collection, after 18 h at room temperature, or after 18 h on ice. Additionally, samples were stored at –16°C or –45°C for up to 28 days. NR activity decreased to near-zero levels under all storage conditions, indicating that this enzyme is unsuitable for delayed analysis. In contrast, GS and PME activities showed species-dependent responses to storage, with increased activity ob-served for T. repens and C. gayana, potentially reflecting tissue degradation processes. F. uhdei exhibited greater stability in enzyme activities, suggesting a higher resilience to storage. These findings highlight the importance of minimizing storage time to preserve enzymatic integrity, particularly for NR, while providing insight into the potential for delayed analysis of GS and PME in specific species. This work offers practical recommendations for future biomonitoring ef-forts in nitrogen deposition studies.},
keywords = {disturbance, neotropical, nitrate reductase, nitrogen deposition, phosphorus, planetary boundaries, plant nutrition, tropical forest, urban ecology},
pubstate = {published},
tppubtype = {article}
}
Understanding how transport and storage conditions affect enzymatic activity is essential for accurate biomonitoring of nitrogen metabolism in plants. This study evaluated the effects of transport conditions and low-temperature storage on the enzymatic activities of nitrate reductase (NR), glutamine synthetase (GS), and phosphomonoesterase (PME) for Chloris gayana, Fraxinus uhdei, and Trifolium repens. Enzymatic activities were measured for leaf samples immediately after collection, after 18 h at room temperature, or after 18 h on ice. Additionally, samples were stored at –16°C or –45°C for up to 28 days. NR activity decreased to near-zero levels under all storage conditions, indicating that this enzyme is unsuitable for delayed analysis. In contrast, GS and PME activities showed species-dependent responses to storage, with increased activity ob-served for T. repens and C. gayana, potentially reflecting tissue degradation processes. F. uhdei exhibited greater stability in enzyme activities, suggesting a higher resilience to storage. These findings highlight the importance of minimizing storage time to preserve enzymatic integrity, particularly for NR, while providing insight into the potential for delayed analysis of GS and PME in specific species. This work offers practical recommendations for future biomonitoring ef-forts in nitrogen deposition studies.
2021
Martínez, D. N.; de la Barrera, E.
Physiological screening of ruderal weed biomonitors of atmospheric nitrogen deposition Journal Article
In: Botanical Sciences, vol. 99, no. 3, pp. 573-587, 2021.
Abstract | Links | BibTeX | Tags: atmospheric pollution, biomass, chlorophyll, invasive species, nitrate reductase, nitrogen, plant nutrition, stable isotopes
@article{Martínez2021,
title = {Physiological screening of ruderal weed biomonitors of atmospheric nitrogen deposition},
author = {D. N. Martínez and E. de la Barrera },
url = {https://botanicalsciences.com.mx/index.php/botanicalSciences/article/view/2789},
doi = {10.17129/botsci.2789},
year = {2021},
date = {2021-05-18},
journal = {Botanical Sciences},
volume = {99},
number = {3},
pages = {573-587},
abstract = {Background: Plants take up various species of reactive nitrogen and their different physiological responses to the increase of nitrogen availability can be useful in biomonitoring.
Questions: Does atmospheric nitrogen deposition affect the physiology of ruderal weeds? Which species are most responsive to the nitrogen deposition?
Studied species: Eleven ruderal weeds.
Study site and dates: Morelia, Michoacán, Mexico. 2019.
Methods: Under scenarios of 10, 20, 40 and 80 kg N ha-1year-1, we quantified plant responses of biomass production, nitrate reductase activity, chlorophyll content, fluorescence, δ15N, nitrogen and carbon content.
Results: Total biomass production increased with the rate of nitrogen deposition for Bidens pilosa, Chloris gayana, Lepidium virginicum, and Pennisetum setaceum, as chlorophyll content in B. pilosa, C. gayana, and L. virginicum. In turn, the below- to above-ground biomass ratio decreased for B. pilosa and C. gayana, as photosynthetic efficiency in C. gayana, L. virginicum, and Chloris pycnothrix. Nitrate reductase activity was only affected in L. virginicumm, C. gayana, and T. officinale.
With the exception of C. pycnothrix, the nitrogen content increased, while the carbon augmented in C. gayana, C. pycnothrix, and P. setaceum. The C/N ratio was reduced in B. pilosa, C. gayana, Chloris virgata, P. setaceum, and T. officinale. The δ15N was increased in B. pilosa, C. gayana, C. virgata and P. setaceum.
Conclusions: Bidens pilosa, C. gayana, L. virginicum, and P. setaceum were the species with more affected variables to nitrogen deposition, which could be useful in the biomonitoring.
},
keywords = {atmospheric pollution, biomass, chlorophyll, invasive species, nitrate reductase, nitrogen, plant nutrition, stable isotopes},
pubstate = {published},
tppubtype = {article}
}
Background: Plants take up various species of reactive nitrogen and their different physiological responses to the increase of nitrogen availability can be useful in biomonitoring.
Questions: Does atmospheric nitrogen deposition affect the physiology of ruderal weeds? Which species are most responsive to the nitrogen deposition?
Studied species: Eleven ruderal weeds.
Study site and dates: Morelia, Michoacán, Mexico. 2019.
Methods: Under scenarios of 10, 20, 40 and 80 kg N ha-1year-1, we quantified plant responses of biomass production, nitrate reductase activity, chlorophyll content, fluorescence, δ15N, nitrogen and carbon content.
Results: Total biomass production increased with the rate of nitrogen deposition for Bidens pilosa, Chloris gayana, Lepidium virginicum, and Pennisetum setaceum, as chlorophyll content in B. pilosa, C. gayana, and L. virginicum. In turn, the below- to above-ground biomass ratio decreased for B. pilosa and C. gayana, as photosynthetic efficiency in C. gayana, L. virginicum, and Chloris pycnothrix. Nitrate reductase activity was only affected in L. virginicumm, C. gayana, and T. officinale.
With the exception of C. pycnothrix, the nitrogen content increased, while the carbon augmented in C. gayana, C. pycnothrix, and P. setaceum. The C/N ratio was reduced in B. pilosa, C. gayana, Chloris virgata, P. setaceum, and T. officinale. The δ15N was increased in B. pilosa, C. gayana, C. virgata and P. setaceum.
Conclusions: Bidens pilosa, C. gayana, L. virginicum, and P. setaceum were the species with more affected variables to nitrogen deposition, which could be useful in the biomonitoring.
Questions: Does atmospheric nitrogen deposition affect the physiology of ruderal weeds? Which species are most responsive to the nitrogen deposition?
Studied species: Eleven ruderal weeds.
Study site and dates: Morelia, Michoacán, Mexico. 2019.
Methods: Under scenarios of 10, 20, 40 and 80 kg N ha-1year-1, we quantified plant responses of biomass production, nitrate reductase activity, chlorophyll content, fluorescence, δ15N, nitrogen and carbon content.
Results: Total biomass production increased with the rate of nitrogen deposition for Bidens pilosa, Chloris gayana, Lepidium virginicum, and Pennisetum setaceum, as chlorophyll content in B. pilosa, C. gayana, and L. virginicum. In turn, the below- to above-ground biomass ratio decreased for B. pilosa and C. gayana, as photosynthetic efficiency in C. gayana, L. virginicum, and Chloris pycnothrix. Nitrate reductase activity was only affected in L. virginicumm, C. gayana, and T. officinale.
With the exception of C. pycnothrix, the nitrogen content increased, while the carbon augmented in C. gayana, C. pycnothrix, and P. setaceum. The C/N ratio was reduced in B. pilosa, C. gayana, Chloris virgata, P. setaceum, and T. officinale. The δ15N was increased in B. pilosa, C. gayana, C. virgata and P. setaceum.
Conclusions: Bidens pilosa, C. gayana, L. virginicum, and P. setaceum were the species with more affected variables to nitrogen deposition, which could be useful in the biomonitoring.