Plant Biotechnology Applications of Zinc Finger Technology

With ever-increasing genomic information combined with modern tools for genome modification, we are entering a new era of plant biotechnology. One major tool used for genome modification is the zinc finger nuclease (ZFN). Here, we discuss how ZFNs have proven useful in many genome modification applications. In order to remove the function of a gene or genes, targeted mutagenesis using ZFNs has been readily demonstrated creating numerous gene knockouts, and gene deletion has been demonstrated with removal of gene segments both native and transgenic up to 9 Mb. Applications for gain of function have also been demonstrated. Precision gene editing using ZFNs has resulted in the development of herbicide tolerance, and numerous forms of targeted gene addition have been exhibited. In addition to genome modification, this chapter also describes the use of zinc finger protein transcription factors (ZFP-TFs) for gene regulation in order to provide useful modification of gene expression resulting in altered phenotypes.