Auxin signaling plays an important role in plant growth and development. It responds to various developmental and environmental events, such as embryogenesis, organogenesis, shoot elongation, tropical growth, lateral root formation, flower and fruit development, tissue and organ architecture, and vascular differentiation. However, there has been little research on the Auxin Response Factor (ARF) genes of tartary buckwheat (Fagopyrum tataricum), an important edible and medicinal crop. The recent publication of the whole-genome sequence of tartary buckwheat enables us to study the tissue and expression profile of the FtARF gene on a genome-wide basis. In this study, 20 ARF (FtARF) genes were identified and renamed according to the chromosomal distribution of the FtARF genes. The results showed that the FtARF genes belonged to the related sister pair, and the chromosomal map showed that the duplication of FtARFs was related to the duplication of the chromosome blocks. The duplication of some FtARF genes shows conserved intron/exon structure, which is different from other genes, suggesting that the function of these genes may be diverse. Real-time quantitative PCR analysis exhibited distinct expression patterns of FtARF genes in various tissues and in response to exogenous auxin during fruit development. In this study, 20 FtARF genes were identified, and the structure, evolution, and expression patterns of the proteins were studied. This systematic analysis laid a foundation for the further study of the functional characteristics of the ARF genes and for the improvement of tartary buckwheat crops.

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.

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.