Phylogenetic relationship and sequence diversity of candidate genes involved in anthocyanin biosynthesis pathway in Carthamus species with contrasting seed coat colors

The morphological structure of seed such as coat color can be considered as effective parameters in the evaluation of resistance to pests. The present study is aimed at achieving these goals: first, to determine the phylogenetic relationship of different species of safflower with different seed coat colors based on three candidate genes in the anthocyanin biosynthesis pathway that encode the early steps (PAL: phenylalanine ammonia-lyase and CHS: chalcone synthase) and the final step (UFGT: flavonoid-3-O-glucosyltransferase); second, based on our previous study on the absence of cyanidin-3-O-glucoside (Cyd-3-glu) in white/brown-seeded genotypes, it can be determined whether the lack of production is related to the absence of genes or the lack of expression. In general, the detection of Cyd-3-glu upstream compounds in all studied safflower genotypes, regardless of the color of the seed coat, can be interpreted as the expression of genes responsible for the synthesis of these compounds in the anthocyanin synthesis pathway. In addition, these findings indicated that the accumulation pattern of the mentioned secondary metabolites could be varied in safflower genotypes according to the seed coat color pattern. Regarding the UFGT gene, the evidence showed that this gene is expressed in safflower genotypes with two different seed coat color patterns, but in each genotype the tendency to produce secondary metabolites is different. Consequently, it seems that UFGT may not only regulate Cyd-3-glu biosynthesis but also involved in biosynthesis of flavonol glucoside in black safflower. Additionally, UFGT only affected flavonol glycosides biosynthesis and had no effect on Cyd-3-glu biosynthesis in white- seeded safflower genotypes.

Automated summary

The characteristics of seed structure, such as coat color, play a significant role in evaluating resistance to pests. This study aims to determine the phylogenetic relationship of safflower species with different seed coat colors based on three candidate genes in the anthocyanin biosynthesis pathway. The research also investigates the absence of cyanidin-3-O-glucoside in white/brown-seeded genotypes and its relation to gene absence or lack of expression. The findings demonstrate that gene expression and secondary metabolite accumulation vary in safflower genotypes according to seed coat color, particularly with regards to the UFGT gene's role in flavonol glucoside biosynthesis.