Expression Analysis of Phenylpropanoid Pathway Genes and Metabolomic Analysis of Phenylpropanoid Compounds in Adventitious, Hairy, and Seedling Roots of Tartary Buckwheat

Tartary buckwheat (Fagopyrum tataricum) is an important crop that belongs to the Polygonaceae family, whose roots have received considerable attention due to the presence of compounds with high nutritional and medicinal value. In this study, we aimed to develop an efficient protocol for the culture of adventitious (ARs) and hairy (HRs) roots on a half-strength Schenk and Hildebrandt (SH) medium containing different concentrations of the auxins, α-naphthaleneacetic acid (NAA), indole-3-butyric acid (IBA), and indole-3-acetic acid (IAA). The highest percentage of root induction (91.67%) was achieved with 0.5 mg/L IAA, whereas the greatest number of roots was found in 1 mg/L IAA. In contrast, 0.1 mg/L IBA returned the longest roots. As expected, HRs were obtained from in vitro leaf explants infected with Agrobacterium rhizogenes R1000. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis of 11 phenolic pathway genes revealed that five genes (FtPAL, FtC3H, FtHQT, FtCHS, and FtANS) were highly expressed in HRs, whereas only four (FtC4H, FtFLS2, FtDFR, and FtANR), and three (Ft4CL, FtCHI, and FtF3H) were recognized in the ARs and seedling roots (SRs), respectively. HPLC analysis of phenolic compounds in different root cultures showed that the majority of the phenolic compounds (both individual and total) were significantly accumulated in the HRs. Principal component analysis (PCA) identified differences among the three root types, whereby HRs were separated from ARs and SRs based on the amount of phenolic compounds present. Analysis of the metabolic pathway revealed that among the identified metabolites, the 3, 2, and 1 pathways were associated with flavonoid, flavone and flavonol, and phenylpropanoid biosynthesis, respectively. Hierarchical clustering analysis and the heat map showed that the different root cultures presented unique metabolites.

Efficiency of herbicide ACRIS (dimethenamid-P + terbuthylazine) on sunflower

Trials with a herbicide Acris, SE (280 g/l of dimethenamid-P + 250 g/l of terbuthylazine) were carried out in the Astrakhan, Krasnodar and Altai regions. The aim of this work is studying biological and economic efficiency of pre-emergence treatment with the combined herbicide Acris, SE on sunflower. The treatment with the herbicide Acris, SE (2.0–3.0 l/ha) made it possible to prevent many annual dicotyledonous weeds: Chenopodium album, Amaranthus retroflexus, Fagopyrum tataricum, Abutilon theophrastii and Solanum nigrum. Ambrosia artemisiifolia, found in the Krasnodar region, is less sensitive to this herbicide. The herbicide Acris, SE was highly effective in suppressing annual monocotyledonous weeds: Echinochloa crusgalli and Panicum miliaceum. Efficiency of the herbicide ACRIS was at the level of the standard Gardo Gold, and at the maximum application rate (3.0 l/ha) exceeded the standard one. Pre-emergence soil treatment with the herbicide Acris, SE did not have a negative effect on the germination of sunflower. Significant increase of sunflower yield was noted in all regions of trials. The most significant values were observed on varieties Flagman and R 453 in the Krasnodar region (8.7–9.2 and 7.0–7.5 quintal/ha, respectively). The lowest yields of sunflower in untreated control (10.2 and 11.0 quintal/ha) were observed in the Altai region, but the relative increase in yield in variants with the herbicide Acris, SE application was maximum (from 29.1 to 67.6% in relation to yields in untreated control). In the Astrakhan region, application rates of the herbicide Acris, SE of 2.5 and 3.0 l/ha were characterized by statistical significance (increases up to 2.5 and 3.2 quintal/ha, respectively).

Genome-Wide Analysis of the Auxin/Indoleacetic Acid Gene Family and Response to Indole-3-Acetic Acid Stress in Tartary Buckwheat (Fagopyrum tataricum)

Auxin/indoleacetic acid (Aux/IAA) family genes respond to the hormone auxin, which have been implicated in the regulation of multiple biological processes. In this study, all 25 Aux/IAA family genes were identified in Tartary buckwheat (Fagopyrum tataricum) by a reiterative database search and manual annotation. Our study provided comprehensive information of Aux/IAA family genes in buckwheat, including gene structures, chromosome locations, phylogenetic relationships, and expression patterns. Aux/IAA family genes were nonuniformly distributed in the buckwheat chromosomes and divided into seven groups by phylogenetic analysis. Aux/IAA family genes maintained a certain correlation and a certain species-specificity through evolutionary analysis with Arabidopsis and other grain crops. In addition, all Aux/IAA genes showed a complex response pattern under treatment of indole-3-acetic acid (IAA). These results provide valuable reference information for dissecting function and molecular mechanism of Aux/IAA family genes in buckwheat.

Effect of Exogenous Sulfur on Photosynthesis System of Fagopyrum tataricum Seedlings Under Cadmium Stress

This study explored the physiological mechanism of adscititious sulfur induced cadmium tolerance in tartary buckwheat (Fagopyrum tataricum) on the photosynthetic reaction system. The results showed that the supplementation of S could boost chlorophyll a and b content during Cd treatment, as well as the chlorophyll a/b ratio. Cd stress significantly increased the contents of ALA, PBG, Urogen III, Coprogen III, and Proto IX, while the Mg-Proto IX and pchlide contents were significantly reduced. These results indicate that Cd stress block the synthesis of chlorophyll through interruption of the synthesis of Mg-Proto IX. The adoption of additional S under Cd stress reversed the above contents to the control level. In addition, Cd stress had no significant effect on iron and calcium content, yet was able to significantly decrease Mg, Mn, and Cu content. The lack of Cu and Mn in the tartary buckwheat leaves consequently resulted in the interruption of the electron transport chain at the oxidation region of the PSII reaction centers. The photosynthesis and quantum yield of the PSII photochemistry were both significantly enhanced with additional sulfur under Cd treatment. In conclusion, the results advance the theoretical mechanism of excess S in alleviating the Cd stress in plants through the photosynthetic pathway.