The transcription factor StTINY3 enhances cold-induced sweetening resistance by coordinating starch resynthesis and sucrose hydrolysis in potato.

The accumulation of reducing sugars in cold-stored tubers, known as cold-induced sweetening (CIS), negatively affects potato processing quality. The starch to sugar interconversion pathways that are altered in cold-stored CIS tubers have been elucidated, but the mechanism that regulates them remains largely unknown. This study identified a CBF/DREB transcription factor (StTINY3) that enhances CIS resistance by both activating starch biosynthesis and repressing the hydrolysis of sucrose to reducing sugars in detached cold-stored tubers. Silencing StTINY3 in a CIS-resistant genotype decreased CIS resistance, while overexpressing StTINY3 in a CIS-sensitive genotype increased CIS resistance, and altering StTINY3 expression was associated with expression changes in starch resynthesis-related genes. We showed first that overexpressing StTINY3 inhibited sucrose hydrolysis by enhancing expression of the invertase inhibitor gene StInvInh2, and second that StTINY3 promoted starch resynthesis by up-regulating a large subunit of the ADP-glucose pyrophosphorylase gene StAGPaseL3, and the glucose-6-phosphate transporter gene StG6PT2. Using electrophoretic mobility shift assays, we revealed that StTINY3 is a nuclear-localized transcriptional activator that directly binds to the dehydration-responsive element/CRT cis-element in the promoters of StInvInh2 and StAGPaseL3. Taken together, these findings established that StTINY3 influences CIS resistance in cold-stored tubers by coordinately modulating the starch to sugar interconversion pathways and is a good target for improving potato processing quality.

Comparative transcriptome reveals distinct starch-sugar interconversion patterns in potato genotypes contrasting for cold-induced sweetening capacity.

Potato accumulates large amounts of soluble sugar during cold storage periods. However, a system based understanding of this process is still largely unknown. Here, we compared the dynamic cold-responded transcriptome of genotypes between cold-induced sweetening resistant (CIS-R) and cold-induced sweetening sensitive (CIS-S) in tubers. Comparative transcriptome revealed that activating the pathways of starch degradation, sucrose synthesis and hydrolysis could be common strategies in response to cold in both genotypes. Moreover, the variation in sugar accumulation between genotypes may be due to genetic differences in cold response, which could be mainly explained: CIS-R genotype was active in starch synthesis and attenuated in sucrose hydrolysis by promoting the coordinate expression of aseries ofgenes involved in starch-sugar interconversion. Additionally, transcription factors, the candidate master regulators of starch-sugar interconversion, were discussed. Taken together, this work has provided an avenue for studying the mechanism involved in the regulation of the CIS resistance.

Distinct cold responsiveness of a StInvInh2 gene promoter in transgenic potato tubers with contrasting resistance to cold-induced sweetening.

Potato (Solanum tuberosum L.) vacuolar invertase (ß-fructofuranosidase; EC 3.2.1.26) inhibitor 2 (StInvInh2) plays an important role in cold-induced sweetening (CIS) of potato tubers. The transcript levels of StInvInh2 were increased by prolonged cold in potato tubers with CIS-resistance but decreased in potato tubers with CIS-sensitivity. However, the transcript regulation mechanisms of StInvInh2 responding to prolonged cold are largely unclear in CIS-resistant and CIS-sensitive genotypes. In the present study, the 5'-flanking sequence of the StInvInh2 was cloned, and cis-acting elements were predicted. No informative differences in StInvInh2 promoter structure between resistant and sensitive-CIS potato genotypes were observed. Histochemical assay showed that the promoter of StInvInh2 mainly governed ß-glucuronidase (GUS) expression in potato microtubers. Quantitative analysis of GUS expression suggested that StInvInh2 promoter activity was enhanced by prolonged cold in CIS-resistant genotype tubers but suppressed in CIS-sensitive tubers. These findings provide essential information regarding transcriptional regulatory mechanisms of StInvInh2 in cold-stored tubers contrasting CIS capacity.

The effects of P6 electrical acustimulation on postoperative nausea and vomiting in patients after infratentorial craniotomy.

BACKGROUND: Postoperative nausea and vomiting (PONV) are frequent and harmful complications after neurosurgery. Current pharmacy-based treatment is the standard of care; it, however, lacks efficiency. Invasive and noninvasive acupuncture at the P6 meridian point has been shown to be effective in the prevention of PONV. We evaluated the effectiveness of transcutaneous electrical acupoint stimulation (TEAS) at P6 for the prophylaxis of PONV in patients undergoing infratentorial craniotomy. METHODS: In this prospective, blind, and randomized study, patients received TEAS at P6 on the dominant side starting 30 minutes before the induction of anesthesia and up to 24 hours after surgery or sham acustimulation at P6. The anesthesia was maintained with sevoflurane/remifentanil and intermittent fentanyl/cisatracurium. Antiemetics with 4 mg ondansetron and 10 mg dexamethasone were administered intraoperatively. Data documenting postoperative episodes of nausea and vomiting and the need for antiemetic rescue (10 mg metoclopramide intramuscularly) were collected. Statistical analysis was performed using the χ test. P<0.05 was considered to be significant. RESULTS: Of the 130 patients enrolled, 119 patients completed the study. The 24-hour cumulative incidence of vomiting was significantly lower in the TEAS group than in the control group (22% vs. 41%, P=0.025). The cumulative incidences of nausea at 6 hours (27% vs. 47%, P=0.019) and 24 hours (33% vs. 58%, P=0.008) after surgery were also significantly lower in the TEAS group compared with the control group. The overall requirements of rescue antiemetics were similar between the groups. CONCLUSION: Perioperative TEAS at P6 may be an effective adjunct to the standard antiemetic drug therapy for the prevention of PONV after infratentorial craniotomy.