Proteomic analyses of somatic and zygotic embryos of Cyclamen persicum Mill. reveal new insights into seed and germination physiology

authored by

Traud Winkelmann, Dimitri Heintz, Alain Van Dorsselaer, Margrethe Serek, Hans Peter Braun

Abstract

In the horticulturally important ornamental species Cyclamen persicum Mill., somatic embryogenesis is an efficient vegetative propagation method and the development of artificial seeds is an ultimate aim. This study aims at a systematic comparison of the proteomes of zygotic embryos, somatic embryos grown in liquid medium containing 30 or 60 g l^-1 sucrose, germinating embryos of both types and endosperm in order to obtain novel insights into seed and germination physiology. Using high resolution two-dimensional isoelectric focussing/sodium dodecylsulfate polyacrylamide gel electrophoresis (2D IEF/SDS PAGE), 74% of the proteins expressed in zygotic embryos were found in similar abundance in somatic embryos grown in 60 g l^-1 sucrose. Somatic embryos grown in 30 g l^-1 sucrose accumulated fewer protein species than those grown in 60 g l^-1. Selected proteins were identified following mass spectrometry (nano-LC-MS/MS). Four enzymes involved in glycolysis (UDP-glucose pyrophosphorylase, fructose bisphosphate aldolase, triosephosphate isomerase and glyceraldehyde-3-phosphate dehydrogenase GAPDH) were specifically induced in somatic embryos. 11S globulin proteins identified by MS were present in high levels in somatic embryos, zygotic embryos and endosperm, whereas 7S globulins were detected mainly in endosperm and zygotic embryos. These are the first storage proteins identified in C. persicum. Xyloglucans are known to be another group of seed storage compounds in C. persicum. Interestingly, xyloglucan endotransglycosylases were found to be highly expressed in endosperm tissue. We discuss the physiological implications of these observations.

Organisation(s)

Woody Plant and Propagation Physiology Section
Institute of Plant Genetics

External Organisation(s)

University of Strasbourg

Type

Article

Journal

PLANTA

Volume

224

Pages

508-519

No. of pages

12

ISSN

0032-0935

Publication date

22.02.2006

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Genetics, Plant Science

Electronic version(s)

https://doi.org/10.1007/s00425-006-0238-8 (Access: Unknown)