Plant & Animal Genomes XVII Conference

January 10-14, 2009
Town & Country Convention Center
San Diego, CA

Map-Based Cloning Of The Cleistogamy Locus

Ning Wang¹ , Sudha Nair¹ , Yerlan Turuspekov¹ , Mohammad Pourkheirandish¹ , Suphawat Sinsuwongwat ¹ , Mohammad Sameri¹ , Hiroyuki Kanamori² , Ichiro Honda³ , Yoshiaki Watanabe³ , Nils Stein⁴ , Thomas Wicker⁵ , Akemi Tagiri¹ , Yoshiaki Nagamura¹ , Takashi Matsumoto¹ , Takao Komatsuda¹

¹  National Institute of Agrobiological Sciences (NIAS), Plant Genome Research Unit, Kannondai 1-2-1, Tsukuba, Ibaraki 305 8602 Japan

²  Institute of the Society for Techno-innovation of Agriculture, Forestry and Fisheries (STAFF), 446-1 Ippaizuka, Kamiyokoba, Tsukuba, Ibaraki, 305-0854, Japan

³  National Institute of Crop Science (NICS) Tsukuba, Kannondai 2-1-18, Ibaraki 305-8518, Japan

⁴  Group Genome Diversity, Dep.Genebank Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Corrensstr. 3, D-06466 Gatersleben, Germany

⁵  Institute of Plant Biology, University of Zürich, Zürich CH8008, Switzerland

Flowers which shed their pollen before opening, and therefore tend to be exclusively autogamous, are referred to as cleistogamous. Cleistogamy is associated with escape from infection by certain fungal pathogens, such as the Fusarium spp. which cause head blight in the cereals, and also inhibits pollen-mediated gene flow. In cleistogamous barley cultivars, the lodicule appears atrophied, and this character is controlled by a recessive allele at the Cly1 gene. We report here the isolation of Cly1, which lies in a genomic region of chromosome 2HL, showing some colinearity with a part of rice chromosome 4. The colinearity is interrupted by a micro-inversion. A population of 6,132 gametes allowed Cly1 to be mapped within a 0.7cM interval defined by two ESTs, and the locus co-segregated with an ortholog of a rice transcription factor. A barley EST homologous with this ortholog was used to screen a barley BAC library. The development of additional markers narrowed the location of Cly1 to a 7kbp region which contained only a single ORF. The expression of this sequence (presumed to be Cly1) was specific to the lodicule. The Cly1 coding sequence of a core collection of 274 cultivars was resequenced, and this produced a clear association between cleistogamy and the presence of a synonymous SNP located in a conserved domain within the C-terminal region. In the presence of the recessive allele, transcription was suppressed, suggesting that the development of the lodicule fails when the Cly1 protein accumulates.