Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 8, 2010
Publication Date: August 1, 2010
Citation: Tyagi, N., Dahleen, L.S., Bregitzer, P.P. 2010. Candidate Genes Within Tissue Culture Regeneration QTL Revisited with a Linkage Map Based on Transcript Derived Markers. Crop Science. 50:1697-1707. Interpretive Summary: Growing plant cells in tissue culture and regenerating new whole plants from those cells is an important tool for genetic studies and crop improvement. The plant regeneration trait in barley is controlled by several regions on the barley chromosomes. Recent reports in barley have shown the order and placement of some genes along the barley chromosomes. We compared this information with the regions located for plant regeneration and found that each contained genes that could be important for regeneration. These included a gene similar to one in rice that has been shown to increase regeneration, plus genes involved with plant hormones, cell division and chloroplast development. Further examination of these genes will help us better understand the process of plant regeneration from barley tissue cultures.
Technical Abstract: Green plant regeneration from tissue culture is under the genetic control of multiple genes. Candidate genes for regeneration have been identified in multiple species using QTL and microarray analyses, and some of these genes have been verified as improving regeneration through transformation. Multiple studies have located QTL for regeneration from barley tissue cultures but these studies have been based on RFLP markers which do not provide information on candidate genes. A recent transcript-derived marker barley map based on expressed sequence tags was used to locate QTL for barley green plant regeneration and identify candidate genes. QTL analysis identified four significant regions, on chromosomes 2H, 3H, 6H and 7H, in places where QTL were previously identified. An additional four regions were suggestive for green and/or albino plant regeneration on chromosomes 1H, 3H, 4H and 5H. Examination of transcript-derived markers at the QTL peaks showed that many genes identified as important for regeneration in other species were located in these QTL peaks, including a gene for ferredoxin-nitrate reductase, genes involved in hormone response and synthesis, cell division/cell cycle, chloroplast development, and transcription factors. Identifying these genes allows manipulation to better understand the processes involved in regeneration from barley tissue cultures.