Nature Plants. Article number:15186 (2015). DOI:10.1038/nplants.2015.186

Authors :

Rohit Mago, Peng Zhang, Sonia Vautrin, Hana Šimková, Urmil Bansal, Ming-Cheng Luo, Matthew Rouse, Haydar Karaoglu, Sambasivam Periyannan, James Kolmer, Yue Jin, Michael A. Ayliffe, Harbans Bariana, Robert F. Park, Robert McIntosh, Jaroslav Doležel, Hélène Bergès, Wolfgang Spielmeyer, Evans S. Lagudah, Jeff G. Ellis, Peter N. Dodds

Abstract :

We identify the wheat stem rust resistance gene Sr50 (using physical mapping, mutation and complementation) as homologous to barley Mla, encoding a coiled-coil nucleotide-binding leucine-rich repeat (CC-NB-LRR) protein. We show that Sr50 confers a unique resistance specificity different from Sr31 and other genes on rye chromosome 1RS, and is effective against the broadly virulent Ug99 race lineage. Extensive haplotype diversity at the rye Sr50 locus holds promise for mining effective resistance genes.

Link :

http://www.nature.com/articles/nplants2015186

Authors :

Dobrovolskaya O, Pont C, Sibout R, Martinek P, Badaeva E, Murat F, Chosson A, Watanabe N, Prat E, Gautier N, Gautier V, Poncet C, Orlov Y, Krasnikov A, Bergès H, Salina E, Laikova L, Salse J.

Plant Physiol. 2015 Jan;167(1):189-99. doi: 10.1104/pp.114.250043

Abstract :

Bread wheat (Triticum aestivum) inflorescences, or spikes, are characteristically unbranched and normally bear one spikelet per rachis node. Wheat mutants on which supernumerary spikelets (SSs) develop are particularly useful resources for work towards understanding the genetic mechanisms underlying wheat inflorescence architecture and, ultimately, yield components. Here, we report the characterization of genetically unrelated mutants leading to the identification of the wheat FRIZZY PANICLE (FZP) gene, encoding a member of the APETALA2/Ethylene Response Factor transcription factor family, which drives the SS trait in bread wheat. Structural and functional characterization of the three wheat FZP homoeologous genes (WFZP) revealed that coding mutations of WFZP-D cause the SS phenotype, with the most severe effect when WFZP-D lesions are combined with a frameshift mutation in WFZP-A. We provide WFZP-based resources that may be useful for genetic manipulations with the aim of improving bread wheat yield by increasing grain number.

Link : http://www.ncbi.nlm.nih.gov/pubmed/25398545

Authors :

Da Cheng Hao, Sonia Vautrin, Chi Song, Ying Jie Zhu, Helene Berges, Chao Sun and Shi Lin Chen

Pak. J. Bot., 47(4): 1347-1357, 2015.

Abstract :

Salvia is a representative genus of Lamiaceae, a eudicot family with significant species diversity and population adaptibility. One of the key goals of Salvia genomics research is to identify genes of adaptive significance. This information may help to improve the conservation of adaptive genetic variation and the management of medicinal plants to increase their health and productivity. Large-insert genomic libraries are a fundamental tool for achieving this purpose. We report herein the construction, characterization and screening of a gridded BAC library for Salvia officinalis (sage). The S. officinalis BAC library consists of 17,764 clones and the average insert size is 107 Kb, corresponding to similar to 3 haploid genome equivalents. Seventeen positive clones (average insert size 115 Kb) containing five terpene synthase (TPS) genes were screened out by PCR and 12 of them were subject to Illumina HiSeq 2000 sequencing, which yielded 28,097,480 90-bp raw reads (2.53 Gb). Scaffolds containing sabinene synthase (Sab), a Sab homolog, TPS3 (kaurene synthase-like 2), copalyl diphosphate synthase 2 and one cytochrome P450 gene were retrieved via de novo assembly and annotation, which also have flanking noncoding sequences, including predicted promoters and repeat sequences. Among 2,638 repeat sequences, there are 330 amplifiable microsatellites. This BAC library provides a new resource for Lamiaceae genomic studies, including microsatellite marker development, physical mapping, comparative genomics and genome sequencing. Characterization of positive clones provided insights into the structure of the Salvia genome. These sequences will be used in the assembly of a future genome sequence for S. officinalis.

2015_Salvia

Authors :

Akpinar BA, Magni F, Yuce M, Lucas SJ, Šimková H, Šafář J, Vautrin S, Bergès H, Cattonaro F, Doležel J, Budak H.

BMC Genomics. 2015 Jun 13;16:453. doi: 10.1186/s12864-015-1641-y.
 

Abstract :

BACKGROUND:

The substantially large bread wheat genome, organized into highly similar three sub-genomes, renders genomic research challenging. The construction of BAC-based physical maps of individual chromosomes reduces the complexity of this allohexaploid genome, enables elucidation of gene space and evolutionary relationships, provides tools for map-based cloning, and serves as a framework for reference sequencing efforts. In this study, we constructed the first comprehensive physical map of wheat chromosome arm 5DS, thereby exploring its gene space organization and evolution.

RESULTS:

The physical map of 5DS was comprised of 164 contigs, of which 45 were organized into 21 supercontigs, covering 176 Mb with an N50 value of 2,173 kb. Fifty-eight of the contigs were larger than 1 Mb, with the largest contig spanning 6,649 kb. A total of 1,864 molecular markers were assigned to the map at a density of 10.5 markers/Mb, anchoring 100 of the 120 contigs (>5 clones) that constitute ~95 % of the cumulative length of the map. Ordering of 80 contigs along the deletion bins of chromosome arm 5DS revealed small-scale breaks in syntenic blocks. Analysis of the gene space of 5DS suggested an increasing gradient of genes organized in islands towards the telomere, with the highest gene density of 5.17 genes/Mb in the 0.67-0.78 deletion bin, 1.4 to 1.6 times that of all other bins.

CONCLUSIONS:

Here, we provide a chromosome-specific view into the organization and evolution of the D genome of bread wheat, in comparison to one of its ancestors, revealing recent genome rearrangements. The high-quality physical map constructed in this study paves the way for the assembly of a reference sequence, from which breeding efforts will greatly benefit.

Link : http://www.ncbi.nlm.nih.gov/pubmed/26070810