Biology subjects

Bolc, P.

Publications and source records attributed to Bolc, P..

3 recordsLinked to original sources

bioRxiv2025

New molecular players: siRNA expression and gene regulation in Hordeum vulgare ageing seeds after germination

Small interfering RNAs (siRNAs), a subclass of small non-coding RNAs, play crucial roles in regulating seed germination and viability through epigenetic mechanisms like RNA-directed DNA methylation (RdDM). This study presents the first comprehensive investigation of siRNA profiles linked to seed viability and germination in barley (Hordeum vulgare), utilizing a unique set of seeds from a single batch subjected to controlled long-term storage. Some seeds lost viability due to moisture exposure from unsealing, creating a natural experimental model to explore vigor effects. sRNA sequencing revealed 85,728 differentially expressed siRNAs, with distinct patterns between regenerated, high-viability, and low-viability seeds. Notably, trans-acting siRNAs (ta-siRNAs) showed peak abundance at different imbibition times depending on seed quality, suggesting dynamic regulation. Around 46% of siRNAs were 21 nucleotides, and 54% were 22 nucleotides long. Gene Ontology and degradome analyses confirmed siRNA target genes involved in vital biological processes such as cytochrome complex function, root development, cell maturation, and carbohydrate metabolism. Despite RNA degradation in low-viability seeds, siRNAs remained relatively stable, indicating their potential role in maintaining seed metabolic activity during dormancy release and germination initiation. This pioneering research uncovers novel insights into siRNA-mediated control of seed longevity and germination, highlighting the innovative use of stable, well-characterized plant material to disentangle molecular mechanisms underpinning seed vigor and germination success.

plant biology↗

bioRxiv2024

k-mer-based GWAS in a wheat collection reveals novel and diverse sources of powdery mildew resistance

BackgroundWheat landraces and cultivars stored in gene banks worldwide represent a valuable source of genetic diversity for discovering genes critical for agriculture, which is increasingly constrained by climate change and inputs reduction. We assembled and genotyped, using DArTseq technology, a panel of 461 accessions representative of the genetic diversity of Swiss wheat material. The collection was evaluated for powdery mildew resistance under field conditions for two consecutive years and at the seedling stage with 10 different wheat powdery mildew isolates. ResultsTo identify the genetic basis of mildew resistance in wheat, we developed a k-mer-based GWAS approach using multiple fully-assembled genomes including Triticum aestivum as well as four progenitor genomes. Compared to approaches based on single reference genomes, we unambiguously mapped an additional 25% resistance-associated k-mers. Our approach outperformed SNP-based GWAS in terms of number of loci identified and precision of mapping. In total, we detected 34 (Pm) powdery mildew resistance loci, including seven previously-described and more importantly 27 novel loci active at the seedling stage. Furthermore, we identified a region associated with adult plant resistance, which was not detected with SNP-based approaches. ConclusionsThe described non-reference-based approach highlights the potential of integrating multiple wheat reference genomes with k-mer GWAS to harness the untapped genetic diversity present in germplasm collections.

genomics↗

bioRxiv2024

Aging and Germination of Long-term Stored Seeds: Can MicroRNAs Unlock the Secrets?

BackgroundSmall non-coding RNAs appear to be one of the key components of the germination process. To investigate how small non-coding RNAs correlate with germination of seeds with different levels of viability, miRNA-Seq analyses were performed. ResultsOur analysis sequencing identified 62 known miRNAs from 11 families and 234 new miRNAs after imbibition process. Among the miRNAs with the highest expression levels, we can mention: miR159, miR168 and miR166. The study placed particular emphasis on miRNAs with significant differences in expression levels at different stages of imbibition and among seeds with different viability. DEG analysis identified 28 miRNAs with significant differences in expression levels, their function was assessed by in silico analyses and confirmed by degradome-seq analysis. The expression of miRNAs was verified by qRT-PCR. ConclusionOur data provides a useful source of information on miRNA during germination long term storage seeds with different viability. The studies suggest that miRNAs are involved in the germination process by their regulation DNA and RNA binding, regulation of developmental process and ribosome.

plant biology↗