|Li, Yiyuan -|
|Xioa, Jianhui -|
|Wu, Jiajie -|
|Kong, Xiuying -|
Submitted to: New Phytologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 4, 2012
Publication Date: July 31, 2012
Citation: Li, Y., Xioa, J., Wu, J., Gu, Y.Q., Kong, X. 2012. A tandem segmental duplication (TSD) in the green revolution gene Rht-D1b region underlies plant height variation. New Phytologist. doi: 10.1111/j.1469-8137.2012.04243.x. Interpretive Summary: Wheat is one of the most widely adapted of all crops, grown on more land than any other crop, and with rice and maize vie yearly for the greatest tonnage of food production worldwide. Wheat is the single most important source of plant calories and protein in the human diet and together with other cereal grains accounts for most of the food directly consumed by humans. Wheat is the largest cereal crop in the world. The dwarfing genes, known as the "green revolution" genes, have made a significant contribution to wheat production worldwide. Among all the dwarfing genes described in wheat, the Rht10 allele identified in Chinese wheat line Aibain 1 showed the strongest dwarfing phenotype. A combinational molecular characterization including Southern blot analysis, target region sequencing, expressing analyses, and transgenic planting overexpressing Rht10 gene were performed to demonstrate the additive effect of tandem duplication of Rht10 genes in Aibian 1. This result suggests that systematic screening for duplications in key agronomic genes may be a valuable method for identifying novel variation for crop improvement.
Technical Abstract: Semi-dwarfing genes Rht-B1b (Rht1) and Rht-D1b (Rht2), known as the “Green revolution” genes, have made a significant contribution to wheat production worldwide. Rht-D1c (Rht10) carried by Chinese wheat line Aibian 1 is an allele at the Rht-D1 locus. It has the strongest effect among all dwarfing genes thus far described in wheat. We found that the Rht-D1c allele was generated through a tandem segmental duplication (TSD) of more than 1 Mb region, resulting in multiple copies of the Rht-D1b allele. The TSD forms a haplotype block in Aiban 1 and its derivatives. Two copies of Rht-D1b in the TSD were three-fold more effective in reducing plant height than a single copy, and transformation with a segment containing the tandemly duplicated copy of Rht-D1b resulted in the same level of reduction of plant height as the original copy in Aibian 1. This result suggests that systematic screening for duplications in key agronomic genes may be a valuable method for identifying novel variation for crop improvement.