Cadmium (Cd) is a naturally occurring toxic heavy metal that adversely affects plant germination, growth, and development. While the effects of Cd have been described on many crop species including rice, maize, wheat and barley, few studies are available on cadmium’s effect on Tartary buckwheat which is a traditional grain in China. We examined nine genotypes and found that 30 µM of Cd reduced the root length in seedlings by between 4 and 44% and decreased the total biomass by 7 to 31%, compared with Cd-free controls. We identified a significant genotypic variation in sensitivity to Cd stress. Cd treatment decreased the total root length and the emergence and growth of lateral roots, and these changes were significantly greater in the Cd-sensitive genotypes than in tolerant genotypes. Cd resulted in greater wilting and discoloration in sensitive genotypes than in tolerant genotypes and caused more damage to the structure of root and leaf cells. Cd accumulated in the roots and shoots, but the concentrations in the sensitive genotypes were significantly greater than in the more tolerant genotypes. Cd treatment affected nutrient uptake, and the changes in the sensitive genotypes were greater than those in the tolerant genotypes, which could maintain their concentrations closer to the control levels. The induction of SOD, POD, and CAT activities in the roots and shoots was significantly greater in the tolerant genotypes than in the sensitive genotypes. We demonstrated that Cd stress reduced root and shoot growth, decreased plant biomass, disrupted nutrient uptake, altered cell structure, and managed Cd-induced oxidative stress differently in the sensitive and tolerant genotypes of Tartary buckwheat.

Tartary buckwheat (Fagopyrum tataricum Gaertn.) is a coarse grain crop rich in flavonoids that are beneficial to human health because they function as anti-inflammatories and provide protection against cardiovascular disease and diabetes. Flavonoid biosynthesis is a complex process, and relatively little is known about the regulatory pathways involved in Tartary buckwheat. Here, we cloned and characterized the FtMYB163 gene from Tartary buckwheat, which encodes a member of the R2R3-MYB transcription factor family. Amino acid sequence and phylogenetic analysis indicate that FtMYB163 is a member of subgroup 7 (SG7) and closely related to FeMYBF1, which regulates flavonol synthesis in common buckwheat (F. esculentum). We demonstrated that FtMYB163 localizes to the nucleus and has transcriptional activity. Expression levels of FtMYB163 in the roots, stems, leaves, flowers, and seeds of F. tataricum were positively correlated with the total flavonoid contents of these tissues. Overexpression of FtMYB163 in transgenic Arabidopsis enhanced the expression of several genes involved in early flavonoid biosynthesis (AtCHS, AtCHI, AtF3H, and AtFLS) and significantly increased the accumulation of several flavonoids, including naringenin chalcone, naringenin-7-O-glucoside, eriodictyol, and eight flavonol compounds. Our findings demonstrate that FtMYB163 positively regulates flavonol biosynthesis by changing the expression of several key genes in flavonoid biosynthetic pathways.

Background: Chalcone synthase (CHS) functions as a pivotal and initiating enzyme in the flavonoid biosynthesis pathway within plants, playing a crucial role in the accumulation and metabolic processes of flavonoids. Despite its importance, there has been no comprehensive analysis or detailed description of the CHS gene family members specifically in Tartary buckwheat. Methods: Based on a comprehensive analysis using multiple bioinformatics approaches and quantitative real−time PCR (qRT−PCR) technology, this study systematically identified and characterized the CHS gene family members from the complete genome sequence of Tartary buckwheat. Results: In this study, we identified a total of 14 FtCHS genes (FtCHS1−FtCHS14) in Tartary buckwheat. Analysis of gene structure and protein motifs showed that most FtCHS genes consist of two exons and a single intron, featuring conserved Chal−sti−synt_N and Chal−sti−synt_C domains. Phylogenetic studies suggested that FtCHS genes can be categorized into four primary groups: Groups I, II, III, and IV. Further analysis of the promoter regions revealed that the FtCHS family genes contain multiple cis−acting elements that respond to light, plant hormones, stress, and developmental cues. By combining phylogenetic analysis with gene expression data, we found that the genes in Group II (FtCHS3, FtCHS4, FtCHS5, and FtCHS6) exhibit significantly elevated expression levels specifically in flowers. Conclusions: Our study indicated that FtCHS is a gene superfamily comprising at least four functional members. The expression patterns of these FtCHS genes suggest their probable involvement in flower−related biological processes in Tartary buckwheat. This work provides fundamental insights into the comprehensive understanding of the functional roles of the CHS gene family in Tartary buckwheat.

Background and aims – Campeiostachys is an allohexaploid perennial genus of the Triticeae tribe (Poaceae). The allopolyploids of Triticeae are produced by interspecific hybridization of different genera. In this study, we investigate the genome origin of Campeiostachys and the relationships of some species based on phylogenetic analyses. Material and methods – Two nuclear (Acc1 and DMC1) and two chloroplast (matK and rps16) DNA regions of the species of Campeiostachys and its related genera were used for phylogenetic analyses. Key results – The Acc1 and DMC1 sequences revealed that the genome composition of all Campeiostachys species in our study is StYH, suggesting that Campeiostachys may have originated by the natural hybridization between species with StY and H genomes, as no species with Y or HY genomes have been found in the wild. The results from the chloroplast regions indicated that the maternal donor of the Campeiostachys species contains the St subgenome. In addition, phylogenetic analysis of the nuclear sequences showed that C. purpuraristata always groups with the species of the C. dahurica complex in the St, Y, or H clade, distinct from other species in the genus. Also, C. calcicola, C. kamoji, and C. tsukushiensis var. transiens are distinct yet closely related species. Conclusion – Campeiostachys species originated from the natural hybridization of the tetraploid species of Roegneria (StY) with the diploid species of Hordeum (H), with Roegneria (StY) acting as the maternal donor. Campeiostachys purpuraristata should be classified into the C. dahurica complex and treated as C. dahurica var. purpuraristata.