Work

Genotypic and transcriptomic characterization of a SAD gene cluster in European hazelnut (Corylus avellana L.)

Year: 2026

Type: article

Abstract: European hazelnut ( Corylus avellana L.) is a nut crop whose kernels are rich in unsaturated fatty acids, a feature that has so far been only marginally studied from a genetic perspective in this species. In the current work, a preliminary genome-wide association study (GWAS) for fatty acid content in hazelnut kernels was conducted on a diversity panel of 89 individuals, using 40,113 single nucleotide polymorphisms (SNPs). The analysis reported significant marker-trait association for five and six SNPs with arachidic acid (C20:0) and linoleic acid (C18:2Δ 9,12 ), respectively. A strong association with arachidic acid ( p value = 2.86 x 10 −11 ) was observed for a SNP on chromosome 4 in proximity of a cluster including seven gene models putatively encoding for stearoyl-[acyl-carrier-protein] (ACP) Δ9-desaturase (SAD), the enzyme that introduces a first double bound in C18 fatty acids in plants. As a parallel approach, a genome-wide characterization of fatty acid desaturases ( FADs ) was performed identifying 27 members belonging to this gene family in the reference genome of this species. Comparative genomics analysis between European hazelnut and other Fagales highlighted the presence of a SAD gene cluster in the other species analysed except Persian walnut ( Juglans regia L.). Finally, the characterization of FAD gene expression profiles in vegetative organs like leaves, petioles, nodes, internodes and roots of both plantlets grown in pot ( in vivo ) and in tissue culture ( in vitro ) was carried out. Differences among the organs in the expression patterns of paralogues of FAD genes were observed, with a general conservation of the transcriptional profiles between the two growth systems. Among the SAD genes arranged in cluster, CaSAD.9 ( LOC132177089 ) showed high expression levels [log 2 (TPM+1) ≥ 6.83] in all the organs of plantlets from both growth systems.

Source: Journal of Agriculture and Food Research

DOI: 10.1016/j.jafr.2026.103294