Abstract Detail

Genomics / Proteomics

Talianova, Martina [1], Griesenbeck, Joachim [2], Oberprieler, Christoph [3].

Copy number and expression of chloroplast and nuclear genes belonging to the Photosystem II and Calvin cycle throughout different ploidy levels in Leucanthemum (Compositeae, Anthemideae).

Polyploidy represents the most important source of evolutionary novelties in plant evolution and speciation. It leads to novel gene combinations and/or to novel gene expression patterns, and thus has considerably affected plant species diversity. An important determinant of the ecological success and economic utility of polyploid plants are their photosynthetic capabilities. Polyploids exhibit larger mesophyll cells with more chloroplasts and increased photosynthetic capacities per cell than their diploid ancestors, and thus photosynthesis provides a good example of phenotypic difference between species with different ploidy level. However, the causes of these differences at the level of underlying genes are not well understood. Since in eukaryotes most of the genes encoding organelle-destined proteins have been horizontally transferred to the nucleus, coordinate expression to produce the correct concentrations of organelle proteins and to maintain organelle function is of a key importance. Major functional complexes of photosynthesis (i.e. Photosystem I, Photosystem II, Calvin cycle, and the light-harvesting complex) are composed of gene families located in either nucleus or chloroplasts. Interestingly, due to cell volume constraints, multiplication of chloroplast in the cell appears not to exactly correspond to the ploidy level change of the nuclear material. Polyploidization of the nuclear genome may thus disrupt the stoichiometry of gene products of nuclear and plastid encoded genes.
In our work, we are studying the relationships of the copy number and expression between chloroplast-encoded gene psbA and nuclear gene psbO (Photosystem II), and between chloroplast-encoded Rubisco large subunit rbcL and nuclear-encoded Rubisco small subunit rbcS throughout different ploidy levels in four closely related species from the genus Leucanthemum (Compositeae, Anthemideae) with different ploidy levels. Our aim is to gain insights into the expression levels of functionally related genes from different compartments (nucleus versus chloroplasts), which can provide us with valuable clues about the stoichiometry regulation as a response to polyploidization.

Broader Impacts:

1 - University of Regensburg, Institute of Botany, Universitätsstr. 31, Regensburg, D-93040, Germany
2 - University of Regensburg, Institute of Biochemistry, Genetics, and Microbiology, Universitätsstr. 31, Regensburg, D-93040, Germany
3 - Institute Of Botany, University Of Regensburg, Universitätsstr. 31, Regensburg, N/A, D-93040, Germany

Keywords:
Polyploidy
expression
Gene duplications.

Presentation Type: Poster:Posters for Topics
Session: P
Location: Grand Salon A - D/Riverside Hilton
Date: Monday, July 29th, 2013
Time: 5:30 PM
Number: PGP002
Abstract ID:366
Candidate for Awards:None