A.m Stanca

Following the screening of a suppression subtractive library developed from durum wheat plants exposed to low temperature for 6 h, two early cold-regulated (e-cor) genes have been isolated. These genes, coding putatively for a ribokinase (7H8) and a C3H2C3 RING-finger protein (6G2), were characterized by the stress-induced retention of a subset of introns in the mature mRNA. This feature was dependent on cold for 7H8 and on cold and dehydration for 6G2. When other genes, such as the stress-related gene WCOR410c, coding for a dehydrin (one intron), or a gene coding for a putative ATP binding cassette transporter (16 introns) were analyzed, no cold-dependent intron retention was observed. Cold-induced intron retention was not observed in mutants defective in the chloroplast development; nevertheless treatment with cycloheximide in the absence of cold was able to promote intron retention for the 7H8 e-cor gene. These results suggest that the cold-induced intron retention reflects the response of the spliceosoma to specific environmental signals transduced to the splicing protein factors through a chloroplast-dependent pathway. Notably, when the 7H8 Arabidopsis orthologous gene was analyzed, no stress induction in terms of mRNA abundance and no cold-dependent intron retention was detected. Otherwise, 6G2 Arabidopsis homologous sequences sharing the same genomic structure of the durum wheat 6G2 showed a similar intron retention event although not strictly dependent on stress.

Abstract Individual reports are presented from representatives from some of the 34 member countries of the ECP/GR (European Cooperative Programme for Crop Genetic Resources Networks) Working Group on Barley at their sixth meeting, which was held in conjunction with the second meeting of the EU Barley Project GENRES CT98-104 regarding the status of research on plant genetic resources and collections, gene conservation, and breeding of barley.

An integrated physical and genetic map represent a prerequisite for DNA sequence assembly of wheat chromosome 5A. About 95,000 BAC clones for 5A were fingerprinted using SnaPshot method and the useful fingerprints were assembled into contigs using both FPC and LTC software. Two minimal tiling paths (MTPs), were defined: FPC-MTP consisting of 4,201 for 5AS and 6,560 for 5AL overlapping BAC clones and LTC-MTP made of 5,412 for 5AS and 8,709 for 5AL overlapping BACs. Both MTPs were organized in three dimensional (3D) pools, to increase the efficiency of further anchoring, that was performed using two different strategies. The anchoring of FPC-MTP was done through screening with several classes of molecular markers mapped on four segregating populations, including SSRs (simple sequence repeat) and based on transposable element-junctions obtained either from literature or by in silico screening of 454-derived 2x coverage of 5A flow sorted DNA. To anchor the LTC-MTP an Agilent 15K specifi...