Characterization and absolute quantification of the Cellulose synthase-like F6 homoeologs in oats

TheCellulose synthase-like F6(CslF6) gene has been reported as a key factor for beta-glucan synthesis in grasses. However, the action of this gene on oat beta-glucan content is poorly understood. The objectives of this study were: (i) to quantify the absolute expression ofCslF6transcripts in oats under field conditions; and (ii) to characterize theCslF6homoeologs in oat genotypes with different levels of beta-glucan content. Developing kernels of five oat genotypes were collected under field conditions in two planting dates. TheCslF6absolute quantification was performed using droplet digital PCR considering global and homoeolog-specific expressions. The third exon of theCslF6gene, which covers approximately 62.2% of the coding region, was sequenced in each homoeolog. TheCslF6expression was highly influenced by planting date, kernel developmental stage, and genotype. HighCslF6transcript number was not associated with high beta-glucan content, indicating the action of a complex biosynthesis pathway controlling this trait in oats. Under stressful conditions, theCslF6expression was more pronounced and associated with beta-glucan content. TheCslF6motif has 1767 bases pair and is highly conserved between A and D homoeologs. Single nucleotide polymorphisms were not identified among the assessed genotypes, regardless of the homoeolog. The results presented in this study may contribute for a better understanding of theCslF6influence on oat beta-glucan content.