Improvement of Transformation Systems
Improvement of transformation systems in major crops such as soybean (Glycine max) and maize (Zea mays) is our continuous effort. This research area includes the improvement of T-DNA integration efficiency and quality, which will make production of transgenic lines more cost-effective and further satisfy the need of genome-wide functional analysis of genes in these crop species.
Small RNA-mediated Gene Silencing
Efficient gene silencing in a complex genome background such as soybean represents a new challenge in transgene technology. Conventional RNAi has been shown to be a powerful tool to accomplish this goal. More recently, atasiRNA has received more attention and becomes one of our current research focuses. We are employing RNAi as well as atasiRNA in soybeans and trying to explore new strategies in improving the efficacy of these approaches in this crop. The experience and lessons learned from down-regulation of several important soybean genes should be applicable for regulation of other genes in soybean. In addition, transgenic soybean lines developed in these studies can be used for plant biology study and soybean trait improvement.
Coordinated gene expression
Conventional approach for expressing multiple genes is through stacking multiple transgene expression cassettes, which has its own promoter and terminator. Such an approach suffers from several drawbacks which include a higher chance of promoter homology-dependent gene silencing, interactions between adjacent transgenes, and increased difficulty in cloning. We are now trying to develop new strategies through coordinated gene expression to overcome these limitations. The success in our new strategies could enhance crop trait stacking and be instrumental to plant biology study.
Reverse genetics tools such as transposon mutagenesis have been demonstrated to have a great utility in knocking-out genes in the plant genome. We had been collaborating with several other institutions on the transposon mutagenesis project. The goal of these projects is to tag a large number of soybean genes with special interest to seed traits. Tagged genes will be mapped to the soybean physical map. Mutant soybean lines and genes whose functions are identified in this study will be a good resource for the soybean research community.