Genetic transformation of Acacia magium cross Acacia auriculiformis and molecular characterization of phenylalanine ammonia-lyase in quaking aspen (Populus tremuloides)

Genetic improvement is needed to improve the product characteristics and mass propagation of plantation-managed pulpwood species, such as Acacia magium × auriculiformis and Populus tremuloides Michx (quaking aspen). Large-scale propagation of selected elite trees can be achieved with in vitro techniques such as tissue culture. Genetic transformation systems are a proven strategy for introducing genes of interest into these pulpwood species. To facilitate these long-term strategies, two independent studies were undertaken for this dissertation to address issues relating to genetic improvement of Acacia and quaking aspen.; In chapter 1, tissue culture and genetic transformation of Acacia magium × aurculiformis are described. This is the first time that whole plant regeneration and gene transformation systems were established for A. magium × aurculiformis using excised tissues from mature plants.; In chapter 2, molecular cloning and characterization of phenylalanine ammonia-lyase (PAL) in quaking aspen, a commonly used lumber and pulpwood species in the Lake States, is presented. Two tissue-specific PAL cDNAs were identified and characterized in this study. This is the first work to compare the expression and localization of distinct PAL genes in quaking aspen.