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36 results on '"Dobrev, P. I."'

29. Rapid separation of Arabidopsis male gametophyte developmental stages using a Percoll gradient

Author

Dupl'áková, Nikoleta, Dobrev, Petre I, Reňák, David, and Honys, David

Abstract

Research investigating the dynamics of male gametophyte (MG) development has proven to be challenging for the plant science community. Here we describe our protocol for separating Arabidopsis MG developmental stages, which is based on the centrifugation of pollen through a discontinuous Percoll concentration gradient. This Percoll gradient can be formed using a pipette, and it does not require a gradient maker. The purity of the isolated developing spores is as high as 70%, and in most separations it is well above 80%. Using this protocol, we can separate four different stages of pollen development—uninucleate microspore (UNM), bicellular pollen (BCP), tricellular immature pollen (TCP) and mature pollen grain (MPG). The duration of the separation procedure, excluding the cutting of flower inflorescences, is 6 h. This is reduced to 4 h when using a vacuum cleaning method to remove the MPGs before the Percoll density separation.

Published
2016
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35. Impact of jasmonic acid on lignification in the hemp hypocotyl

Author

Behr, Marc, Pokorna, Eva, Dobrev, Petre I., Motyka, Václav, Guignard, Cédric, Lutts, Stanley, Hausman, Jean-Francois, and Guerriero, Gea

Abstract

ABSTRACTPhytohormones are crucial molecules regulating plant development and responses to environmental challenges, including abiotic stresses, microbial and insect attacks. Most notably, phytohormones play important roles in the biosynthesis of lignocellulosics. Jasmonates are involved in secondary growth and secondary metabolism, such as phenylpropanoids and lignin biosyntheses. At the physiological and molecular levels, the actions of phytohormones depend on subtle concentration changes, as well as antagonistic equilibria between two or more of these molecules. In this article, we investigate the consequences of jasmonic acid (JA) spraying on young hemp hypocotyls. First, we show that JA application results in changes in the monomeric composition of lignin. Second, we highlight that, five days after application, JA leads to an increase in salicylic acid (SA) content in hemp hypocotyls. These results are discussed in the light of the known antagonism between JA and SA at both the physiological and molecular levels.

Published
2019
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36. Purification and determination of plant hormones auxin and abscisic acid using solid phase extraction and two-dimensional high performance liquid chromatography.

Author

Dobrev PI, Havlícek L, Vagner M, Malbeck J, and Kamínek M

Subjects
Abscisic Acid analysis, Indoleacetic Acids analysis, Plant Growth Regulators analysis, Reproducibility of Results, Abscisic Acid isolation & purification, Chromatography, High Pressure Liquid methods, Indoleacetic Acids isolation & purification, Plant Growth Regulators isolation & purification
Abstract

A method for separation and purification of plant hormones auxin and abscisic acid based on mixed mode reversed-phase anion-exchange solid phase extraction and two-dimensional HPLC was developed. Two-dimensional HPLC in "heart cutting" mode was very efficient in the purification of these two hormones. Its purification power is high enough to allow reliable on-line quantification of both hormones even with non-selective detectors.

Published
2005
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