Down-Regulation of Small Rubber Particle Protein Expression Affects Integrity of Rubber Particles and Rubber Content in Taraxacum brevicorniculatum

0385325 - ÚPT 2013 RIV US eng J - Journal Article
Hillebrand, A. - Post, J. J. - Wurbs, D. - Wahler, D. - Lenders, D. - Krzyžánek, Vladislav - Pruefer, D. - Gronover, CH. S.
Down-Regulation of Small Rubber Particle Protein Expression Affects Integrity of Rubber Particles and Rubber Content in Taraxacum brevicorniculatum.
PLoS ONE. Roč. 7, č. 7 (2012), e41874:1-9. ISSN 1932-6203. E-ISSN 1932-6203
Institutional support: RVO:68081731
Keywords : Hevea-Brasiliensis * Parthenium-Argentatum * Elongation-Factor * Silencing Affects * Surface-Structure * Oil Bodies * Latex * Prenyltransferase * Biosynthesis * Stability
Subject RIV: CE - Biochemistry
Impact factor: 3.730, year: 2012

The biosynthesis of rubber is thought to take place on the surface of rubber particles in laticifers, highly specialized cells that are present in more than 40 plant families. The small rubber particle protein (SRPP) has been supposed to be involved in rubber biosynthesis, and recently five SRPPs (TbSRPP1-5) were identified in the rubber-producing dandelion species Taraxacum brevicorniculatum. Here, we demonstrate by immunogold labeling that TbSRPPs are localized to rubber particles, and that rubber particles mainly consist of TbSRPP3, 4 and 5 as shown by high-resolution two-dimensional gel electrophoresis and mass spectrometric analysis. We also carried out an RNA-interference approach in transgenic plants to address the function of TbSRPPs in rubber biosynthesis as well as rubber particle morphology and stability. TbSRPP-RNAi transgenic T. brevicorniculatum plants showed a 40-50% reduction in the dry rubber content, but neither the rubber weight average molecular mass nor the polydispersity of the rubber were affected. Although no phenotypical differences to wildtype particles could be observed in vivo, rubber particles from the TbSRPP-RNAi transgenic lines were less stable and tend to rapidly aggregate in expelling latex after wounding of laticifers. Our results prove that TbSRPPs are very crucial for rubber production in T. brevicorniculatum, probably by contributing to a most favourable and stable rubber particle architecture for efficient rubber biosynthesis and eventually storage.
Permanent Link: http://hdl.handle.net/11104/0214612