Transformation as a Tool for Genetic Analysis in Populus

Abstract

We summarize the outlook for using transformation as a genetic tool in Populus. Transformation approaches avoid the major obstacle to performing genetics experiments in trees -namely long generation cycles and the difficulty of inbreeding to reveal loss of function alleles. Dominant transgenic alleles allow modifications in gene function to be readily observed in primary transformants. Although transformation has been mainly used for reverse genetics (where the gene sequence of interest is known), transgenic mutagenesis approaches such as activation tagging and gene/enhancer traps have also been shown to enable forward genetics (where the phenotype, not the gene, is known). We outline challenges and needs for more efficient use of transformation tools. These include expansion of the transformation toolbox (e.g., promoters, vectors, targeting), and improved ability to conduct field trials to study gene function in native and plantation environments (in spite of regulatory obstacles). Because of the power of transformation, it will remain a major genetic research tool for dissection of gene function in Populus for many years to come. It is the key biological attribute that makes poplar the most powerful model organism for genetic analysis of woody plant growth, adaptation, and development.

Abscisic acid signalling mediates biomass trade‐off and allocation in poplar

“…As the implementation of transgene technologies, variability among transformation events is well known and has been ascribed to differences in gene expression intensity, the insertion site of the construct, etc. (Peach & Velten, ; Busov et al ., ). Although the transformation events generated with the same construct had been selected for similar phenotypes under laboratory conditions, our results show that moderate differences became pronounced during our long‐term field study because of the exponential nature of growth and interaction with the natural environment.…”

NEP-TC a rRNA Methyltransferase Involved on Somatic Embryogenesis of Tamarillo (Solanum betaceum Cav.)

“…The difficulty in relating individual genes to phenotypes (Wang and Waterhouse, 2001), and the substantial gene redundancy that many plant gene families present (Busov et al, 2010), have already been referred as relevant limitations for the dissection of individual gene function(s) through functional genomics approaches as the ones used in this work. Genetic redundancy is a major problem for dissecting gene function in all plant species.…”

Direct regeneration from in vitro leaf and petiole tissues of Populus tremula ‘Erecta’

“…The genetic background and functions of these genes should be further recapitulated in poplar trees with a different genetic background using the genetic transformation method. Significant effort has been made to develop a transformation system for poplar species (Busov et al 2009); however, the efficient transformation system has been developed for a very limited number of poplar species/cultivars. For example, hybrid aspen clone INRA 717-IB4 (Populus tremula 9 P. alba) has been intensively used for gene transformation (Peña and Seguin 2001;Confalonieri et al 2003;Ye et al 2009).…”