Delineating the structural, functional and evolutionary relationships of sucrose phosphate synthase gene family II in wheat and related grasses
1 Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstr. 3, D-06466 Gatersleben, Germany
2 Sardar Vallabh Bhai Patel University of Agriculture and Technology, Modipuram, Meerut, Uttar Pradesh 250110, India
3 Iwate Biotechnology Research Center, Narita 22-174-4, Kitakami, Iwate 024-0003, Japan
4 Plant Breeding Institute, Christian-Albrechts University of Kiel, Olshausenstrasse 40, 24098 Kiel Germany
5 Department of Agronomy and Plant Breeding, College of Agriculture, Isfahan University of Technology, 841568311, Isfahan, Iran
6 Department of Plant Pathology, Throckmorton Plant Sciences Center, Kansas State University, Manhattan, KS 66506, USA
BMC Plant Biology 2010, 10:134 doi:10.1186/1471-2229-10-134Published: 30 June 2010
Sucrose phosphate synthase (SPS) is an important component of the plant sucrose biosynthesis pathway. In the monocotyledonous Poaceae, five SPS genes have been identified. Here we present a detailed analysis of the wheat SPSII family in wheat. A set of homoeologue-specific primers was developed in order to permit both the detection of sequence variation, and the dissection of the individual contribution of each homoeologue to the global expression of SPSII.
The expression in bread wheat over the course of development of various sucrose biosynthesis genes monitored on an Affymetrix array showed that the SPS genes were regulated over time and space. SPSII homoeologue-specific assays were used to show that the three homoeologues contributed differentially to the global expression of SPSII. Genetic mapping placed the set of homoeoloci on the short arms of the homoeologous group 3 chromosomes. A resequencing of the A and B genome copies allowed the detection of four haplotypes at each locus. The 3B copy includes an unspliced intron. A comparison of the sequences of the wheat SPSII orthologues present in the diploid progenitors einkorn, goatgrass and Triticum speltoides, as well as in the more distantly related species barley, rice, sorghum and purple false brome demonstrated that intronic sequence was less well conserved than exonic. Comparative sequence and phylogenetic analysis of SPSII gene showed that false purple brome was more similar to Triticeae than to rice. Wheat - rice synteny was found to be perturbed at the SPS region.
The homoeologue-specific assays will be suitable to derive associations between SPS functionality and key phenotypic traits. The amplicon sequences derived from the homoeologue-specific primers are informative regarding the evolution of SPSII in a polyploid context.