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Molecular factors involved in the formation of secondary vascular tissues and lignification in higher plants

studies of CuZn-SOD and members of MYB and zinc-finger transcription factor families

Karlsson, Marlene (2003). Molecular factors involved in the formation of secondary vascular tissues and lignification in higher plants. Diss. (sammanfattning/summary) Umeå : Sveriges lantbruksuniv., Acta Universitatis Agriculturae Sueciae. Silvestria, 1401-6230 ; 280
ISBN 91-576-6514-1
[Doctoral thesis]

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The formation of secondary vascular tissues involves complex processes and many steps, a number of which have been examined in detail in this study. A novel CuZn-SOD, with a high pI and thus denoted hipI-SOD, was identified and characterized in Pinus sylvestris. Results from immunolocalisation analyses indicated that it is localised in lignified structures, suggesting that SOD might participate in the formation of secondary cell walls and lignification. To further investigate its role in these processes, a Zinnia mesophyll cell system was set up. This enabled us to follow the differentiation from mesophyll cell to tracheary element. Various inhibitors against SOD and H2O2-production were applied. The results suggested that HipI-SOD might have a novel and important function in secondary cell wall formation and lignification processes. The expression pattern and localization of the protein during formation of tracheary elements support this assumption. The other part of this study involved analysis of transcription factors and their regulation, especially in secondary vascular tissues. The genes encoding three MYB-transcription factors and one novel Zinc-finger transcription factor were found in an EST-library from the cambial region of hybrid aspen (Populus tremula L. x tremuloides Michx.). The genes were cloned and characterized and their regulation by hormones, sucrose and gravity was investigated. The genes were found to be under hormone and sucrose control, and their expression altered during tension wood formation. Transgenic plants were constructed, carrying one of two antisense constructs of MYB-genes, PttMYB46 or PttMYB76, which were strongly expressed in lignified tissues. Analysis of plants with either of these constructs displayed a complex phenotype, including reduced growth, increased concentration of some phenolic acids and changes in lignin composition. Some of the phenotypic traits were indicative of strong investment in defensive characters.

Authors/Creators:Karlsson, Marlene
Title:Molecular factors involved in the formation of secondary vascular tissues and lignification in higher plants
Subtitle:studies of CuZn-SOD and members of MYB and zinc-finger transcription factor families
Series Name/Journal:Acta Universitatis Agriculturae Sueciae. Silvestria
Year of publishing :August 2003
Number of Pages:47
ALLI. Karpinska, B., Karlsson, M., Schinkel, H., Streller, S., Süss, K-H., Melzer, M. & Wingsle, G. (2001) A novel superoxide dismutase with a high isoelectric point in higher plants. Expression, regulation, and protein localization. Plant Physiology 126: 1668-1677. II. Karlsson, M., Melzer, M., Prokhorenko, I., Johansson, T. & Wingsle, G. HipI-Superoxide dismutase, a possible regulator of hydrogen peroxide in the lignification of tracheary elements in Zinnia elegans L. Submitted. III. Karlsson, M., Stenberg, A., Schrader, J., Sterky, F., Bhalerao, R., Wingsle, G. & Karpinska, B. MYB transcription factors in the secondary vascular tissues of hybrid aspen and their regulation by hormones, sucrose and gravity. Submitted. IV. Karlsson, M., Witzell, J., Srivastava, M., Wiklund, S., Rodriguez-Buey, M., Edlund, U., Karpinska, B., Mellerowicz, E.J. & Wingsle, G. Morphological, anatomical and chemical changes in hybrid aspen carrying antisense constructs of a MYB transcription factor. Submitted.
Place of Publication:Umeå
ISBN for printed version:91-576-6514-1
Publication Type:Doctoral thesis
Full Text Status:Public
Agris subject categories.:F Plant production > F62 Plant physiology - Growth and development
Subjects:Not in use, please see Agris categories
Agrovoc terms:superoxide dismutase, zinnia, transcription factors, cell walls, lignification, salicylates, vascular tissues
Keywords:Superoxide dismutase, Zinnia system, MYB-transcription factors, Zinc-finger transcription factor, Secondary cell wall formation, Lignification, Salicylates
Permanent URL:
ID Code:328
Department:(S) > Dept. of Forest Genetics and Plant Physiology
Deposited By: Marlene Karlsson
Deposited On:20 Aug 2003 00:00
Metadata Last Modified:02 Dec 2014 10:03

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