Accumulation of the bitter substance quercetin mediated by the overexpression of a novel seed-specific gene FtRDE2 in Tartary buckwheat.

Tartary buckwheat (Fagopyrum tataricum) is frequently employed as a resource to develop health foods, owing to its abundant flavonoids such as rutin. However, the consumption of Tartary buckwheat (TB) is limited in food products due to the strong bitterness induced by the hydrolysis of rutin into quercetin. This transformation is facilitated by the degrading enzyme (RDE). While multiple RDE isoenzymes exist in TB, the superior coding gene of FtRDEs has not been fully explored, which hinders the breeding of TB varieties with minimal bitterness. Here, we found that FtRDE2 is the most abundant enzyme in RDE crude extracts, and its corresponding gene is specifically expressed in TB seeds. Results showed that FtRDE2 has strong rutin hydrolysis activity. Overexpression of FtRDE2 not only significantly promoted rutin hydrolysis and quercetin accumulation but also dramatically upregulated genes involved in the early phase of flavonoid synthesis (FtPAL1、FtC4H1、Ft4CL1, FtCHI1) and anthocyanin metabolism (FtDFR1). These findings elucidate the role of FtRDE2, emphasizing it as an endogenous factor contributing to the bitterness in TB and its involvement in the metabolic regulatory network. Moreover, correlation analysis revealed a positive relationship between the catalytic activity of RDE extracts and the expression level of FtRDE2 during seed germination. In summary, our results suggest that FtRDE2 can serve as a promising candidate for the molecular breeding of a TB variety with minimal bitterness.

[Clinical observation on deep needling at Xiaguan (ST 7) with round sharp needle combined with plum-blossom needle for trigeminal neuralgia of wind and heat].

OBJECTIVE: To compare the clinical therapeutic effect between deep needling at Xiaguan (ST 7) with round sharp needle combined with plum-blossom needle and conventional acupuncture in patients with trigeminal neuralgia (TN) of wind and heat, and explore its mechanism. METHODS: A total of 60 patients with TN of wind and heat were randomized into an observation group (30 cases) and a control group (30 cases). In the observation group, deep needling with round sharp needle was applied at Xiaguan (ST 7), and tapping with plum-blossom needle was applied at Yangbai (GB 14), Quanliao (SI 18), Dicang (ST 4), Sibai (ST 2), etc. of affected side. In the control group, conventional acupuncture was applied at the same acupoints selected in the observation group. The treatment was given once a day, 5 times a week for 4 weeks in the both groups. Before and after treatment, the scores of short-form McGill pain questionnaire (SF-MPQ), TCM syndrome, patient global impression of change (PGIC) and comprehensive symptom were observed, the serum levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), vasoactive intestinal peptide (VIP) and ß-endorphin (ß-EP) were detected, and the adverse reaction was observed in the both groups. RESULTS: After treatment, the scores of PRI, PPI, VAS, TCM syndrome, PGIC and comprehensive symptom and the serum levels of IL-6, TNF-α and VIP were decreased compared before treatment in the both groups (P<0.05), and the variations of above indexes in the observation group were larger than those in the control group (P<0.05). After treatment, the serum levels of ß-EP were increased compared before treatment in the both groups (P<0.05), and the variation of that in the observation group was larger than the control group (P<0.05). No severe adverse reaction was observed in the both groups. CONCLUSION: Deep needling at Xiaguan (ST 7) with round sharp needle combined with plum-blossom needle can effectively treat the trigeminal neuralgia of wind and heat and relieve pain, its therapeutic effect is superior to conventional acupuncture. The mechanism may be related to the regulation of serum IL-6, TNF-α, VIP and ß-EP.