OsPPG encodes a pseudouridine-5'-phosphate glycosidase and regulates rice spikelet development

Florets are the basic structural units of spikelets,and their morphogenesis determines the yield and quality of rice grains.However,whether and how pseudouridine-5’-phosphate glycosidase participates in rice spikelet development remains an open question.In this study,we identified a novel gene,OsPPG,which encodes a peroxisome-localized pseudouridine-5’-phosphate glycosidase and regulates the development of rice spikelets.osppg mutants exhibited abnormal sterile lemma,lemma,palea,lodicule,stamens,and pistils;male sterility;shorter panicles;and reduced plant height.OsPPG was found to regulate several OsMADS genes,thereby affecting the morphogenesis of rice spikelets.Furthermore,metabolomics revealed that the OsPPG gene was involved in the decomposition of pseudouridine via the pyrimidine metabolism pathway and may affect the jasmonic acid signaling pathway.These results suggest that OsPPG is a key regulator of rice spikelet development.

A randomized,double-blind,placebo-controlled trial assessing the efficacy and safety of tegaserod in patients from China with chronic constipation

AIM： To evaluate the efficacy and safety of tegaserod, 6 mg twice daily （b.i.d.）, in men and women with chronic constipation （CC） from China. METHODS： This was a multicenter, double-blind, placebo-controlled study. Following a 2-wk treatmentfree baseline period, patients were randomized to receive either tegaserod （6 mg b.i.d.） or placebo （b.i.d.） for 4 wk. An analysis of covariance with repeated measures was used to determine the overall effect of treatment for the primary efficacy variable; the change from baseline in the number of complete spontaneous bowel movements （CSBMs） during the 4-wk treatment period. Secondary efficacy endpoints included other measures of response in terms of CSBMs, and patients＇ daily and weekly assessment of bowel habits. Safety was also assessed, based on the incidence and severity of adverse events （AEs）. RESULTS： A total of 607 patients were randomized to receive either tegaserod （n = 304） or placebo （n = 303）. Tegaserod treatment resulted in a rapid and significant increase from baseline in the adjusted mean number of CSBMs per week over wk 1-4 compared with placebo （1.39 vs 0.91, P = 0.0002）. A statistically significant difference in favor of tegaserod was also observed for a mean increase ≥ 1 CSBM/wk over wk 1-4 （47.7% vs 35.0%, tegaserod vs placebo, respectively, P = 0.0018） and for the absolute number of≥ 3 CSBMs/wk over wk 1-4 （25.0% vs 14.5%, tegaserod vs placebo, respectively, P = 0.0021）. Improvements in other symptoms of CC were also seen in the tegaserod group, including improved stool form and reduced straining. In addition, more patients in the tegaserod group reported satisfactory relief from their constipation symptoms. The frequency and severity of AEs was comparable between tegaserod and placebo groups, with the exception of a greater incidence of diarrhea in patients receiving tegaserod （3.6%） compared with placebo （1.7%）. CONCLUSION： Tecjaserod treatment improved multiple symptoms of CC and was associated with a favorable safety profile.