Biomedical subjects

Renate Horn

Publications and source records attributed to Renate Horn.

3 recordsLinked to original sources

PubMed2026

Genome-wide analysis of FATA associated with drought tolerance in tetraploid potato (Solanum tuberosum).

The cuticle represents the outer most protective barrier against biotic and abiotic stresses. It is composed of cutin and waxes and protects plants from desiccation, UV, cold, mechanical stresses, and pathogens. GWAS/BSAseq combined with SeqSNP analyses in an association panel of 34 potato cultivars had revealed that the acyl-ACP thioesterase FATA (Soltu.DM.06G033680.1) is significantly associated with drought tolerance in potato. Apart from three FATB genes, only one FATA gene is present in potato that has the highest homology to FATA2 in Arabidopsis. FATA is responsible for the export of C18:1 fatty acid from chloroplast into cytosol, which is necessary for the biosynthesis of cutin. A knockout mutant of AtFATA2 was analyzed with regard to the cuticle permeability and to drought tolerance as well as recovery. Loss of FATA function leads to higher sensibility to water deficit in Arabidopsis, but to no change in recovery. The increased permeability of the cuticle in the fata2 knockout mutant as shown indirectly by higher chlorophyll leaching might play a role in this. Haplotypes for FATA were identified for the two potato cultivars Albatros and Désirée. All Désirée haplotypes and Albatros haplotypes 1, 3 and 4 were also revealed by former potato pan genome studies, while Albatros haplotype 2 is unique and has not been described before. Protein models were developed to investigate the influence of different SNPs in the haplotypes on the predicted protein structure and especially the substrate cavity. In potato, protein modeling suggests that only the hypothetical isoform B of FATA might be able to process oleoyl-ACP, but not hypothetical isoform A. However, this hypothesis needs to be verified by enzyme activity assays.

FATA↗

PubMed2006

Expression analysis of the sunflower SF21 gene family reveals multiple alternative and organ-specific splicing of transcripts.

The SF21 proteins were originally identified in sunflower pollen and in the stigmatic and transmitting tissues of sunflower pistils [Kräuter-Canham, R., Bronner, R., Evrard, J.L., Hahne, G., Friedt, W. and Steinmetz, A., 1997. A transmitting tissue- and pollen-expressed protein from sunflower with sequence similarity to the human RTP protein. Plant Science 129, 191-202.]. They are polypeptides of about 350 amino acids showing limited but significant sequence similarities with the animal NDR/RTP family of proteins of yet unknown function. Based on genomic sequence information derived from BAC clones containing SF21-related sequences we have identified transcripts generated from three different, but highly related genomic copies: SF21C, SF21D and SF21E. A sequence analysis of SF21C transcripts amplified by RT-PCR using specific primer pairs revealed a complex splicing pattern producing a minimum of three splice variant forms of the protein, one of 355 residues, and two truncated proteins of 90 and 138 amino acids, respectively. One of these variants was detected only in styles from pollinated florets, indicating organ-specific splicing. Two other splice variants, identified for a related transcript, SF21D, generate proteins differing by an 8-residue extension at their C-terminus. This analysis of SF21 transcripts in sunflower supports already existing evidence that alternative splicing is complex and common in plants.

Alternative Splicing↗

PubMed2005

Candidate gene database and transcript map for peach, a model species for fruit trees.

Peach (Prunus persica) is a model species for the Rosaceae, which includes a number of economically important fruit tree species. To develop an extensive Prunus expressed sequence tag (EST) database for identifying and cloning the genes important to fruit and tree development, we generated 9,984 high-quality ESTs from a peach cDNA library of developing fruit mesocarp. After assembly and annotation, a putative peach unigene set consisting of 3,842 ESTs was defined. Gene ontology (GO) classification was assigned based on the annotation of the single "best hit" match against the Swiss-Prot database. No significant homology could be found in the GenBank nr databases for 24.3% of the sequences. Using core markers from the general Prunus genetic map, we anchored bacterial artificial chromosome (BAC) clones on the genetic map, thereby providing a framework for the construction of a physical and transcript map. A transcript map was developed by hybridizing 1,236 ESTs from the putative peach unigene set and an additional 68 peach cDNA clones against the peach BAC library. Hybridizing ESTs to genetically anchored BACs immediately localized 11.2% of the ESTs on the genetic map. ESTs showed a clustering of expressed genes in defined regions of the linkage groups. [The data were built into a regularly updated Genome Database for Rosaceae (GDR), available at (http://www.genome.clemson.edu/gdr/).].

Breeding↗