The expression characteristics and allelic variation of AnVromindoline-1/3 in Avena nuda L.

Abstract

Oat is a worldwide cultivated crop with nutritional, ecological and economic value. The hardness of oat is closely related to the damage to the grain during harvesting, washing, threshing and hulling, and has an important impact on the processing quality and eating quality of oats. Vromindolines are a group of proteins specific to the Avena genus and are responsible for the softness of oat endosperm. Avena nuda is an allohexaploid, and is an important grain and feed crop in China. Vromindolines have been studied in the genus Oat, but have not been reported in Avena nuda. In this study, we performed paraffin sectioning and scanning electron microscopy analysis on oat kernels with different hardness, and the sequence characteristics, allelic variation, expression patterns and subcellular localization of Vromindoline-1 and Vromindoline-3 genes in Avena nuda were also analyzed. The results showed that the cell structure and ultrastructure of soft oat variety grains are significantly different from those of hard oats variety. PCR amplification and sequence analysis showed that the lengths of AnVin-1 and AnVin-3 genes were 444 and 429 bp, respectively, and AnVin-1 existed in the oat A, C and D genomes. Expression analysis in different tissues showed that AnVin-1A, AnVin-1C, AnVin-1D and AnVin-3C were expressed to varying degree in roots, stems and leaves. Expression analysis at the panicle developmental stage showed that the expression levels of these four genes first increased and then decreased, with the highest expression levels at 14 days after pollination. In addition, the expression levels of AnVin-1C and AnVin-3C in soft oat variety were higher than those in hard oats at 14 DAP. Among the single nucleotide polymorphisms among 18 AnVin-1C and 9 AnVin-3C gene sequences, AnVin-1C6 and AnVin-3C2 genes had three haplotypes in a oat natural population. Based on the allelic variation sites of AnVin-1C6, a cleavage amplified polymorphic sequence marker was established, which explained 1.44% of the variation in hardness. The above results of this study indicated that AnVin-1 and AnVin-3 genes were involved in kernel development and might affect kernel firmness.