Effects of Combining the Genes Controlling Anthocyanin and Melanin Synthesis in the Barley Grain on Pigment Accumulation and Plant Development

Abstract

Anthocyanins and melanins are phenolic pigments of plants and accumulate in seed envelopes of the barley grain, thereby giving them a blue, purple, or black color. To explore the effects of combined accumulation of anthocyanins and melanins in the grain, a barley near-isogenic line (NIL), characterized by simultaneous accumulation in both pigments, was developed using a marker-assisted approach. The presence of both pigments in the grain pericarp was evaluated by light microscopy. Emergence of anthocyanin pigmentation proved to be temporally separated from that of melanin, and the formation of anthocyanin pigments began at an earlier stage of spike maturation. During spike maturation, a significantly higher total anthocyanin content was noted in the created NIL than in the parental anthocyanin-accumulating NIL, indicating a positive influence of the Blp1 gene on the anthocyanin content at some developmental stages. In a comparative analysis of yield components, it was found that the observed differences between the barley NILs are possibly caused by environmental factors, and the presence of pigments does not decrease plant productivity. Our results should facilitate investigation into genetic mechanisms underlying overlaps in the biosynthesis of pigments and into breeding strategies aimed at the enrichment of barley varieties with polyphenols.