Search

Background The effects of the increase of atmospheric CO2 on agricultural productivity have been mainly analyzed through its impact on biomass yield, and little attention has been directed to quality traits, such as nutritional or organoleptic attributes. For this study, plants of hot Habanero pepper ( Capsicum chinense Jacq.) were grown in growth chambers under three different CO2 levels: 380 (normal atmospheric value), 760 and 1140 µmol mol−1, and their effects on pod yield, size, color and pungency, were monitored. Results The total number of pods per plant increased by 88.5% at the highest CO2, in comparison to plants grown at normal CO2 conditions. Pod size and yield per plant also increased when plants were grown at the highest CO2 concentration (partial pressure). Furthermore, total capsaicinoids contents in ripe peppers under a high CO2 atmosphere were 27% higher than those from plants under lower concentrations, but it was not the case for immature pods. Conclusion These data suggest that the increase of atmospheric CO2 could modify specific routes of secondary metabolism as well as others desirable traits, thus affecting the quality of Capsicum pepper products. © 2012 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

A method for measuring the content of total capsaicinoids by in situ densitometry on thin layer chromatography (TLC) plates is described. This method is easy to perform, reproducible, and can detect up to 0.5 µg of capsaicinoids in unpurified organic extracts. Identity of the compounds was assigned by comparing the chromatographic behavior of the putative capsaicinoids with that of standards. Under the assayed conditions, capsaicin could not be separated from dihydrocapsaicin by TLC; however, the amounts detected in different tissues was always equal to the sum of the individual compounds, as quantified by gas chromatography, suggesting that the method is reliable. [ABSTRACT FROM AUTHOR]

Alkaloids are part of the chemical arsenal designed to protect plants against an adverse environment. Therefore, their synthesis and accumulation are frequently induced in response to certain environmental conditions and are mediated by chemical signals, which are formed as the first responses to the external stimulus. A set of experiments using Catharanthus roseus seedlings is presented to illustrate this interaction. Using the well characterized induction of monoterpenoid indole alkaloid synthesis in response to methyl jasmonate, one chemical mediator; simple and reproducible experiments are proposed to demonstrate this type of plant-environment interaction to plant physiology or biochemistry B.Sc. students. After exposure to the inducer, seedlings are analyzed for alkaloid accumulation and for the increase of tryptophan decarboxylase (TDC) enzyme activity by means of thin layer chromatography, followed by UV spectrophotometry. Alkaloids should increase as a result of the exposure to the inducer, as well as TDC activity, which plays a critical role in channeling carbon skeletons from primary to secondary metabolism in this plant. [ABSTRACT FROM AUTHOR]

A simple and reproducible technique for the quantitation of the main monoterpenoid indole alkaloids from aerial tissues of Catharanthus roseus , based on in situ densitometry-thin layer chromatography, is described. The sensitivity of this method was enough to detect the amounts of ajmalicine, catharanthine, and vindoline present in 100 mg of dried leaf tissue and in different in vitro culture systems. The main advantage of this method is that it allows the proper separation of these alkaloids using a single solvent mixture, as well as the scanning of the corresponding spots at a single wavelength, reducing the number of chromatographic plates required and the time invested in the analysis. [ABSTRACT FROM AUTHOR]

Shoot apex, leaf primordia, leaf sections and roots from Mexican prickly poppy seedlings, were inoculated with Agrobacterium tumefaciens harboring the binary vector pCAMBIA2301, which contained the ß-glucuronidase (uid A) gene. Histochemical ß-glucuronidase (GUS) assay in infected explants showed transient gus gene expression between 3 and 12 days after inoculation. To our knowledge, this is the first report of A. mexicana susceptibility to A. tumefaciens-mediated genetic transformation. [ABSTRACT FROM AUTHOR]

In situ RT-PCR presents advantages over other expression analysis methods due to its rapid processing and low-cost equipment. However, this technique is not without its challenges. A protocol based on a capsule made from centrifuge tubes that offers advantages over slides is presented. This capsule protects histological sections from drying out, and its easy assembly reduces time pauses between incubations. In addition, the container size where the sample is deposited allows the addition and withdrawal of the different solutions. The capsule does not need previous sealing after each incubation, and, above all, it is a low-cost and accessible material. A guideline for tissue sectioning using a cryostat that offers advantages over other sectioning methods is also described., (© 2024. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

Protoplasts are plant cells from which the pectocellulosic cell wall has been removed, thus keeping the plasma membrane intact. For plant secondary metabolites research, this system is a powerful tool to study the metabolites' dynamics inside the cells, such as the subcellular localization of proteins, characterization of gene function, transcription factors involved in metabolite pathways, protein transport machinery, and to perform single-cell omics studies. Due to its lack of a cell wall, better images of the interior of the cell can be obtained compared to the whole tissue. This allows the identification of specific cell types involved in the accumulation of specialized metabolites, such as alkaloids, given their autofluorescence properties. Here is a simplified protocol to obtain protoplasts from leaves and in vitro cell cultures from Argemone mexicana, which produces the pharmacologically important alkaloids berberine and sanguinarine., (© 2024. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

The main parameters for the estimation of growth within in vitro cultures are reviewed. Procedures to measure these parameters are described, emphasizing in each case their convenience of use, depending on the features of the culture to evaluate.