Abstract
BackgroundClonal propagation is highly desired especially for valuable horticultural crops. The method with the potentially highest multiplication rate is regeneration via somatic embryogenesis. However, this mode of propagation is often hampered by the occurrence of developmental aberrations and non-embryogenic callus. Therefore, the developmental process of somatic embryogenesis was analysed in the ornamental crop Cyclamen persicum by expression profiling, comparing different developmental stages of embryogenic cell cultures, zygotic vs. somatic embryos and embryogenic vs. non-embryogenic cell cultures.ResultsThe analysis was based on a cDNA microarray representing 1,216 transcripts and was exemplarily validated by realtime PCR. For this purpose relative transcript abundances of homologues of a putative receptor kinase, two different glutathione S-transferases (GST), a xyloglucan endotransglycosylase (XET) and a peroxidase (POX) were quantitatively measured by realtime PCR for three different comparisons. In total, 417 genes were found to be differentially expressed. Gene Ontology annotation revealed that transcripts coding for enzymes that are active in the extracellular compartment (apoplast) were significantly overrepresented in several comparisons. The expression profiling results are underpinned by thorough histological analyses of somatic and zygotic embryos.ConclusionsThe putative underlying physiological processes are discussed and hypotheses on improvement of the protocol for in vitro somatic embryogenesis in Cyclamen persicum are deduced. A set of physiological markers is proposed for efficient molecular control of the process of somatic embryogenesis in C. persicum. The general suitability of expression profiling for the development and improvement of micropropagation methods is discussed.
Highlights
Clonal propagation is highly desired especially for valuable horticultural crops
Global expression profiling results We analysed the expression of 1,216 transcripts (Additional file 1) during somatic and zygotic embryogenesis in C. persicum using a cDNA microarray derived from annotated transcripts of a previous analysis [29]
In order to find key physiological pathways that are (i) fundamentally involved in s.e. in C. persicum (ii) prone to cause aberrant development and (iii) accessible for manipulation by in vitro culture, we subjected our data to Gene Ontology (GO) annotation [30] (Figure 2)
Summary
The method with the potentially highest multiplication rate is regeneration via somatic embryogenesis. This mode of propagation is often hampered by the occurrence of developmental aberrations and non-embryogenic callus. Plant micropropagation on a commercial scale has developed since the 1960s and gained high impact during the last centuries for clonal mass propagation especially of ornamental crops [1,2]. The expression of single genes has frequently been investigated in the course of somatic and zygotic embryogenesis and the importance of certain gene products has been proven for individual stages of development in different plant species. Developmental aberrations, can rarely be attributed to single or few genes in the course of s.e. Instead, it can be assumed that the whole expression pattern is changed during the course of the culture. In problem-oriented approaches, microarray-based expression analyses might give a more complete picture of the cultures' physiology that subsequently allows molecular physiologically founded progression of propagation protocol development
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
