Transfer of knowledge about flowering and vegetative propagation from model species to bulbous plants

Abstract

The extensive characterization of plant genes and genome sequences summed to the continuous development of biotechnology tools, has played a major role in understanding biological processes in plant model species. The challenge for the near future is to generate methods and pipelines for an efficient transfer of this knowledge to economically important crops and other plant species. In the case of flower bulbs, which are economically very important for the ornamental industry, flowering time control and vegetative propagation constitute the most relevant processes for agronomical improvements. Those processes have been reasonably studied in reference species, making them excellent candidates for translational investigations in bulbous plant species. The approaches that can be taken for the transfer of biological knowledge from model to non-model species can be roughly categorized as "bottom-up" or "top-down". The former approach usually goes from individual genes to systems, also known as a "gene-by-gene" approach. It assumes conservation of molecular pathways and therefore makes use of sequence homology searches to identify candidate genes. "Top-down" methodologies go from systems to genes, and are e.g. based on large scale transcriptome profiling via heterologous microarrays or RNA sequencing, followed by the identification of associations between phenotypes, genes, and gene expression patterns and levels. In this review, examples of the various knowledge-transfer approaches are provided and pros and cons are discussed. Due to the latest developments in transgenic research and next generation sequencing and the emerging of systems biology as a matured research field, transfer of knowledge concerning flowering time and vegetative propagation capacity in bulbous species are now within sight.

Molecular Regulation of Temperature-Dependent Floral Induction in Tulipa gesneriana

“…For further identification of putative flowering timecontrolling genes and to gain insight into the global transcriptional changes, an initial top-down approach was followed (Leeggangers et al, 2013). The top-down approach consisted of an untargeted analysis using GO enrichment and a clustering analysis.…”

PLAZA 3.0: an access point for plant comparative genomics

“…The extraction of biological knowledge from a genome sequence, through the detection of similarities and differences with genomes of closely or more distantly related species, is an important concept. By using such comparative approaches, (i) knowledge can be transferred from model to non-model organisms ( 2 ), (ii) insights can be gained in the evolution of specific genes or entire metabolic and signaling pathways ( 3 ), (iii) genes of importance for niche-specific plant adaptations can be identified ( 4 ) and (iv) large-scale genomic events, such as whole-genome duplications (WGDs), can be unveiled ( 5 ). As the number of potential pairwise comparisons grows superlinearly with the number of available genomes, such comparative analyses require considerable computational resources.…”

Mechanisms of vegetative propagation in bulbs : a molecular approach

“…Both axillary and adventitious meristems constitute an important source of vegetative propagation in species where sexual reproduction takes considerably much longer or is not very successful (reviewed in (Leeggangers et al 2013)). The first case occurs in flower bulbs.…”

“…Tulip bulbs are equivalent to a compacted plant whose stem shortened into a basal plate that bears modified concentric leaves (bulb-scales); one central apical bud (the Shoot Apical Meristem; SAM) and one axillary bud per bulb scale (Le Nard and de Hertogh 1993; Leeggangers et al 2013). Note that the outer bulb-scale dries out at the end of the growing season and turns into a so-called "tunica", which will protect the bulb from dehydration during storage time.…”